Solid-state luminescent materials

Abstract

To provide a light storage material exhibiting large light storage quantum yield and brightness and an article using the same.SOLUTION: A luminescent material characterized in that a molecular structure of minimum-excited triplet state T1 is optimized by using a functional B3LYP and a basis function 6-31G (d) in the density functional method, in a most optimized structure of the lowest excited triplet state T1, in the relationship of transition dipole moments between higher order singlet excited states Sn and ground state S0 of the lowest excited triplet state T1 (μSn-S0), a spin-orbit mutual function between Sn and T1 (SOCSn-T1), and energy difference between Sn and T1 (ESn-T1), when defined as Pn=μSn-S0SOCSn-T1 / ESn-T1, a range of (ΣnPn)2 calculated using a functional PBE0 and a basis function TZP in the density function method is 4.00×10-7D2 or larger, a square of spin-orbit mutual function (SOCT1-S0) of T1 and S0 calculated using the functional PBE0 and the basis function TZP in the density function method is 1×101 cm-2 or smaller.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a light-emitting material, a light-storing material, a display medium, and an ink. [Background technology]

[0002] In recent years, materials that remain luminescent after the excitation light is turned off have attracted attention. Such materials are used in emergency indicator lights for darkrooms that can be seen in dark environments in emergencies. Furthermore, by taking advantage of the characteristic of phosphorescent materials that remain luminescent after the excitation light is turned off, phosphorescence can be detected using low-cost, compact photodetectors without relying on surrounding phosphors or fluorescent impurities. Therefore, applications such as anti-counterfeiting media and bioimaging have begun to be considered.

[0003] The three main factors that represent the performance of such phosphorescent materials are the quantum yield of phosphorescence at room temperature (Φ DE ), the average lifespan of the phosphorescent DE ), the intensity of the glow (I DE ) are listed. DE and τ DE is expressed by the following formula:

[0004]

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[0005] In addition, in order to visually recognize and detect the luminescence after the irradiation of the excitation light is stopped, Φ DE The phosphorescence yield (Φ DE t=0.02-1s ) is important, for example, Φ DE Even if is large, the delay time will be long and Φ DE t=0.02-1s If the value is small, the phosphorescence will not be visible in a bright environment, or if the object to which the phosphorescent material is attached is small, the detector will not be able to detect the phosphorescence.

[0006] Non-Patent Document 1 reports a material that utilizes the phosphorescence phenomenon due to the trapping mechanism in ion-doped oxide semiconductors. In such materials, after electrons transition from the valence band to the conduction band during the light absorption process (Figure 1, (1)), most of the energy is usually released as fluorescence rather than phosphorescence (Figure 1, (2)). At that time, some of the electrons are trapped in trap states derived from the doped ions (Figure 1, (3)). The trapped electrons then return to the conduction band (Figure 1, (4)), and then immediately return to the valence band, causing phosphorescence (Figure 1, (5)). The time of delayed emission is determined by the time spent in the trap state.

[0007] Non-Patent Document 2 also reports a similar trapping mechanism for the phosphorescence phenomenon in a mixture of donor and acceptor molecules. In this material, after the donor (D) or acceptor (A) molecules absorb light (Figure 2, (1)), a charge-separated state is formed between the donor and acceptor molecules (Figure 2, (2)), and light is immediately emitted without phosphorescence (Figure 2, (2)). Some electrons or holes diffuse and, in some cases, are trapped in trap levels (Figure 2, (4)). The electrons or holes then return to the donor molecules (Figure 2, (5)) and immediately emit fluorescence (Figure 2, (6)). Depending on the time spent diffusing or in the trap level, light emission persists after the excitation light irradiation is stopped, demonstrating the phosphorescence function.

[0008] Non-Patent Documents 3 to 5 report examples of materials in which fluorescent dopant molecules are doped into conjugated host molecules. In these materials, singlet oxygen is generated by light irradiation, which is absorbed by the conjugated host molecules in the presence of oxygen (Figure 3, (1)). A chemical reaction between the singlet oxygen and the conjugated host molecule generates a conjugated dioxetane derivative (Figure 3, (2)). Depending on the structure of the conjugated moiety, the dioxetane derivative subsequently decomposes, generating an excited state of the conjugated ketone (Figure 3, (3)). Energy is then transferred from the excited state of the conjugated ketone to the guest molecule, forming the excited state of the guest (Figure 3, (4)). The guest then immediately emits fluorescence (Figure 3, (5)). After the formation of the conjugated dioxetane derivative, a delay occurs depending on the time it takes for the conjugated ketone to be formed, resulting in the development of a phosphorescent function. Non-Patent Documents 3 to 5 also propose bioimaging.

[0009] Additionally, Non-Patent Document 6 and Patent Document 1 report materials that exhibit a phosphorescence phenomenon utilizing room-temperature phosphorescence. In such materials, molecules absorb light to form the lowest singlet excited state (S1) (Figure 4, (1)), which then undergoes intersystem crossing to a triplet state, forming the lowest triplet excited state (T1) (Figure 4, (2)). Many compounds that do not contain heavy atoms have a slow phosphorescence rate (radiative process from T1) (Figure 4, (3)), and therefore a slow intramolecular vibrational deactivation rate (Figure 4, (4)). When a host that undergoes slow deactivation due to energy transfer to the host material is used (Figure 4, (5)), slow room-temperature phosphorescence is emitted. Because the rate of room-temperature phosphorescence is a slow photophysical process, a phosphorescence function is observed in which the emission continues for as long as several seconds to 10 seconds after the excitation light irradiation is stopped. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Patent No. 5424172 [Non-patent literature]

[0011] [Non-Patent Document 1] K. Van den Eeckhout, PF Smet, D. Poelman, Materials 2010, 3, 2536. [Non-patent document 2] R. Kabe, C, Adachi, Nature 2017, 550, 384. [Non-patent document 3] M. Palner, K. Pu, S. Shao, J. Rao, Angew. Chem. Int. Ed. 2015, 54, 11477. [Non-patent document 4] Q. Miao, C. Xie, X Zhen, Y. Lyu, H. Duan, X. Liu, J. V Jokerst, K. Pu, Nat. Biotech. 2017, 35, 1102. [Non-patent document 5] J. Huang, X. Zhen, Z. Zeng, J. Li, C. Xie, Q. Miao, J. Chen, P. Chen, K. Pu, Nat. Commun. 2019, 10, 2064. [Non-patent document 6] S. Hirata, K. Totani, T. Yamashita, H. Kaji, SR Marder, T. Watanabe, C. Adachi, Adv. Funct. Mater. 2013, 23, 3386. Summary of the Invention [Problem to be solved by the invention]

[0012] However, some of the phosphorescent materials shown in Non-Patent Documents 1 to 5 emit light for several minutes to over an hour after the irradiation of excitation light is stopped. DE and Φ DE t=0.02-1sHowever, the problem is that the light-storage behavior can only be observed in the dark, and unlike fluorescent materials, it has not been used in applications where the surroundings are bright. Furthermore, because various fluorescent materials exhibit a significant increase in luminance with increasing excitation light intensity, they can detect fluorescence from very small objects, making them useful for various sensors and bioimaging applications. However, fluorescent materials such as those described in Non-Patent Documents 1 to 5 do not exhibit an increase in luminance with increasing excitation light intensity, making it impossible to detect luminescence when the object is 10 μm or smaller. While the advantage of luminescence imaging over other imaging technologies is its high resolution, existing fluorescent materials have not been used for high-resolution imaging because they cannot detect the luminescence phenomenon when the object is small.

[0013] Furthermore, the room-temperature phosphorescent light-storing materials disclosed in Non-Patent Document 6 and Patent Document 1 have the problem that the quantum yield of light-storing is as low as 14% or less.

[0014] The present invention has been made with the aim of solving the problems in the above-mentioned existing inventions, and its object is to provide a luminous material that exhibits a high luminous quantum yield and luminance, and an article using the same. [Means for solving the problem]

[0015] The molecular structure of the lowest excited triplet state T1 was optimized using the density functional theory with the functional B3LYP and the basis set 6-31G(d). In the optimized structure of the lowest excited triplet state T1, the higher singlet excited state S n and the ground state S0, the transition dipole moment (μ Sn-S0 ), S n and T1, the spin-orbit interaction (SOC Sn-T1 ), and S n and T1 (E Sn-T1 ) in the relationship P n =μ Sn-S0 SOC Sn-T1 / E Sn-T1 When we define The density functional theory was calculated using the functional PBE0 and the basis set TZP (Σ n P n ) 2 The range is 4.00×10 -7 D 2 That's all, Spin-orbit interactions (SOC) of T1 and S0 calculated using functional PBE0 and basis set TZP in density functional theory T1-S0 ) squared is 1×10 1 cm -2 is as follows: In either the optimized structure of the ground state S0 or the optimized structure of the lowest singlet excited state S1, which are optimized using the functional B3LYP and the basis set 6-31G(d) in the density functional theory, the oscillator strength (f S1-S0 ) is 0.2 or less. 2. The luminescent material according to claim 1, wherein the molecular structure of the lowest excited triplet state T1 is optimized using the functional B3LYP and the basis set 6-31G(d) in a density functional theory, and the optimized structure is used to calculate formula (11) in a density functional theory using the functional PBE0 and the basis set TZP, where the value of the luminescent material is 100 times or less than the value of compound (12).

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[0016] [3] The molecule is the energy difference between S1 and T1 (E S1-T1 ) is 0.2 eV or more. [4] The light-emitting material according to any one of [1] to [3], wherein the molecule is a secondary aromatic amine or a tertiary aromatic amine. [5] The light-emitting material according to any one of [1] to [3], wherein the molecule is an aromatic amine having two or three aromatic or heterocyclic rings in which a carbon atom on the ring is directly bonded to a nitrogen atom, at least one of the aromatic or heterocyclic rings in which a nitrogen atom on the ring is directly bonded to a nitrogen atom is an antenna unit and at least one is a center unit, and the T1 energy of the center unit is smaller than the T1 energy of the antenna unit. [6] A solid light-storing material comprising the luminescent material according to any one of [1] to [5], wherein the concentration of the luminescent material is 0.001% by mass to 30% by mass. [7] A display medium having a layer containing the solid state light-storing material according to [6]. [8] Particles containing the solid light-storing material according to [6] and having a diameter of 10 μm or less. [9] An ink comprising the particles according to [8]. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a phosphorescent material that exhibits a high phosphorescent quantum yield and brightness, and an article using the same. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is an explanatory diagram illustrating the light-storage phenomenon due to the trap mechanism in an ion-doped oxide semiconductor. [Figure 2] FIG. 2 is an explanatory diagram illustrating the phosphorescent phenomenon of a material consisting of a mixture of donor molecules (D molecules) and acceptor molecules (A molecules). [Figure 3] FIG. 3 is an explanatory diagram illustrating the phosphorescent phenomenon that utilizes the chemical reaction of the host molecule with oxygen. [Figure 4] FIG. 4 is an explanatory diagram illustrating the phosphorescence phenomenon caused by room temperature phosphorescence. [Figure 5]FIG. 5 is a graph showing the relationship between the accumulated luminance immediately after the irradiation of the excitation light is stopped and the excitation light intensity in Example 1 and Comparative Examples 1 and 2. [Figure 6] FIG. 6 shows the emission spectra of Sample 5 when irradiated with 360 nm excitation light (top) and immediately after the irradiation was stopped (bottom). [Figure 7] FIG. 7 is a graph showing the temperature (T) dependence of τP of Sample 5. [Figure 8] FIG. 8 is a graph showing the temperature (T) dependence of kNR+kQ of Sample 5. [Figure 9] FIG. 9 is a graph showing the relationship between (ΣnPn)2 and kP in Examples 2 and 3 and Comparative Examples 4 to 11. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, one embodiment of the present invention will be described, but the examples in the following embodiment do not limit the present invention.

[0020] "Light-emitting materials" The luminescent material according to the present invention has a higher singlet excited state S in the optimized structure of T1. n and the ground state S0, the transition dipole moment (μ Sn-S0 ), S n and T1, the spin-orbit interaction (SOC Sn-T1 ), and S n and T1 (E Sn-T1 ), P n =μ Sn-S0 SOC Sn-T1 / E Sn-T1 When we define n P n ) 2 The range is 4.00×10 -7 D 2 and the spin-orbit interaction (SOC T1-S0 ) squared is 1×10 1 cm -2 or less, and the oscillator strength (f S1-S0) is 0.2 or less. This molecule can provide a phosphorescent material and an article using the same that exhibit a high phosphorescent quantum yield and brightness.

[0021] In detail, the molecular structure of the lowest excited triplet state T1 is optimized using the functional B3LYP and the basis set 6-31G(d) in the density functional theory. The molecular structure is optimized using the functional B3LYP and the basis set 6-31G(d) in the density functional theory. In the optimized structure of the lowest excited triplet state T1, the higher singlet excited state S n and the ground state S0, the transition dipole moment (μ Sn-S0 ), S n and T1, the spin-orbit interaction (SOC Sn-T1 ), and S n and T1 (E Sn-T1 ), P n =μ Sn-S0 SOC Sn-T1 / E Sn-T1 When the definition is made, it is preferable to satisfy the following. The density functional theory was calculated using the functional PBE0 and the basis set TZP (Σ n P n ) 2 The range is 4.00×10 -7 D 2 That's all. Spin-orbit interactions (SOC) of T1 and S0 calculated using functional PBE0 and basis set TZP in density functional theory T1-S0 ) squared is 1×10 1 cm -2 below. In either the optimized structure of S0 or the optimized structure of S1, which are optimized using the functional B3LYP and the basis set 6-31G(d) in the density functional theory, the oscillator strength (f S1-S0 ) is less than or equal to 0.2. In this specification, room temperature refers to 25° C. Furthermore, physical property values measured or calculated at room temperature are indicated with (RT).

[0022] (Φ in room temperature phosphorescent materials DE and τ DE ) In the case of room temperature phosphorescent materials, Φ DE and τ DE is the room temperature phosphorescence quantum yield (Φ P (RT)) and room temperature phosphorescence lifetime (τ P (RT)). Φ P (RT)τ P (RT) is expressed by the following formula:

[0023]

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[0024] where Φ ISC (RT) is the yield of intersystem crossing from the lowest excited singlet state (S1) to the triplet state at room temperature, k P is the phosphorescence rate constant of the dye, k NR (RT) is the rate constant of the decay from the lowest triplet excited state (T1) to the ground state (S0) based on the vibration of the dye at room temperature, k Q (RT) is the rate at which the dye is deactivated by interactions such as energy transfer from the dye to the surrounding host at room temperature. From Equations 3 and 4, a large Φ is required to obtain efficient and long-lived room-temperature phosphorescence. ISC (RT) and k P , small k NR (RT) and k Q (RT) is required, and k P >k NR (RT)+k Q The relationship (RT) is desirable. ISC (RT) is expressed by the following formula:

[0025]

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[0026] where k F is the fluorescence rate constant of the dye, k IC (RT) is the rate constant of deactivation of the dye from S1 to S0 due to intramolecular vibration at room temperature, kISC (RT) is the rate constant for intersystem crossing from S1 to the triplet state. ISC To obtain (RT), at least k ISC (RT)>k F The relationship k is necessary. ISC Control of (RT) is complicated when heavy atoms are not utilized, so k F In many cases, reducing Φ ISC (RT) can be increased. F is f S1-S0 Since it is proportional to f S1-S0 The molecular design of the pigment reduces the ISC This is suitable for obtaining (RT).

[0027] (k P Regarding k P The theoretical literature dates back to the 1960s. P is expressed by the following formula: (H. Gropper, F. Ber. Doerr, Bunsen-Ges. Phys. Chem. 1963, 67, 46.)

[0028]

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[0029] The first term of Equation 6, Σ n P n is the second term Σ n P n If ' is sufficiently larger than ', then Equations 6 to 8 can be simplified as follows:

[0030]

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[0031] By calculation (Σ n P n ) 2 and experimentally measured k P Since there is a good correlation between (Figure 9), the simplification by Equation 9 is statistically meaningful, and (Σ nP n ) 2 The calculation of k P 9 shows the calculation results for Table 2 of the example. n P n ) 2 and experimentally measured k p 10 is a graph showing the relationship between

[0032] (k NR (Regarding RT) k NR There is theoretical literature from the 1970s that suggests that (RT) can be theoretically proportionally expressed as follows: (Metz, F.; Friedrich, S.; Hohlneicher, G. Chem. Phys. Lett. 1972, 16, 353-358.)

[0033]

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[0034] Since FC is a term that is strongly dependent mainly on the energy difference between T1 and S0 (phosphorescence wavelength), between molecules with similar phosphorescence wavelengths, at least the first term SOC from Eq. T1-S0 2 The molecule with larger k NR As (RT) becomes larger, the phosphorescent function is lost. From this, SOC T1-S0 2 By reducing k p can be made larger.

[0035] The molecule of the present invention is in the optimized structure of T1, which is obtained by optimizing the molecular structure of the lowest excited triplet state T1 using the functional B3LYP and the basis set 6-31G(d) in the density functional theory. Higher singlet excited state S n and the ground state S0, the transition dipole moment (μ Sn-S0 ), S n and T1, the spin-orbit interaction (SOC Sn-T1 ), and S nand T1 (E Sn-T1 ), P n =μ Sn-S0 SOC Sn-T1 / E Sn-T1 When the definition is given, the calculation was performed using the functional PBE0 and the basis set TZP in the density functional theory (Σ n P n ) 2 The range is 4.00×10 -7 D 2 and the spin-orbit interaction (SOC T1-S0 ) squared is 1×10 1 cm -2 The following is the result.

[0036] (Σ n P n ) 2 is 4.00 x 10 -7 D 2 More than 8.00 x 10 is preferable. -7 D 2 The above is more preferable. This can increase the probability of emitting phosphorescence when a triplet excited state is formed.

[0037] T1 and S0 spin-orbit interaction (SOC T1-S0 ) squared, i.e. (SOC T1-S0 ) 2 is 1 x 10 1 cm -2 Less than 1×10 is preferred 0 cm -2 The following is more preferable: This reduces the probability that phosphorescence will be deactivated when a triplet excited state is formed, thereby extending the phosphorescence lifetime and providing a phosphorescent function.

[0038] The molecule of the present invention is characterized in that, in either the optimized structure of S0 or the optimized structure of S1, which are optimized using the functional B3LYP and the basis set 6-31G(d) in the density functional theory, the oscillator strength (f S1-S0 ) is less than 0.2. S1-S0) is preferably 0.2 or less, more preferably 0.1 or less, which makes it possible to increase the probability of forming a triplet excited state.

[0039] The molecules of the present invention have an energy difference between S1 and T1 (E S1-T1 ) is preferably 0.2 eV or more. S1-T1 ) is preferably 0.2 eV or more, more preferably 0.5 eV or more, which can prevent the triplet excited state from returning to the singlet state at high speed and preventing the emission of non-long-lasting delayed fluorescence.

[0040] (molecule) The molecule of the present invention has the above-mentioned properties and can exhibit high-intensity phosphorescence at room temperature. Specific examples of the molecule will be described below.

[0041] The molecule of the present invention preferably has a central atom, at least one antenna unit and at least one center unit bonded to the central atom, which is typically a nitrogen atom. The antenna unit determines the three-dimensional structure of the molecule and affects the degree of twisting of the molecule. The center unit functions as a chromophore and affects the phosphorescent properties such as the emitted color. The center unit typically has a structure common to fluorescent materials. In this molecule, the T1 energy of the center unit is preferably smaller than the T1 energy of the antenna unit.

[0042] The molecule of the present invention is preferably an aromatic amine, more preferably a secondary aromatic amine or a tertiary aromatic amine. In a secondary aromatic amine or a tertiary aromatic amine, the functional groups bonded to the nitrogen atom include an aromatic ring or a heterocyclic ring and a functional group other than a hydrogen atom, which causes a twist in the molecule around the nitrogen atom, thereby achieving the energy state of the present invention. Furthermore, the secondary aromatic amine preferably has two groups having an aromatic ring or a heterocyclic ring as the functional group bonded to the nitrogen atom. The tertiary aromatic amine preferably has two or three groups having an aromatic ring or a heterocyclic ring as the functional group bonded to the nitrogen atom. The aromatic amine preferably has an aromatic ring or heterocycle in which a carbon atom on the ring is directly bonded to a nitrogen atom, and the aromatic amine preferably has two or three aromatic rings or heterocycles in which a carbon atom on the ring is directly bonded to a nitrogen atom. This facilitates the formation of a twist between the antenna unit and the center unit centered on the nitrogen atom, making it possible to improve the efficiency of forming a triplet excited state. Furthermore, (SOC T1-S0 ) 2 effectively (Σ n P n ) 2 This allows for long-life, highly efficient room-temperature phosphorescence.

[0043] The aromatic amine preferably has at least one antenna unit and at least one center unit. In this case, the antenna unit and the center unit are each preferably a group having an aromatic ring or a heterocycle, more preferably a group having an aromatic ring or a heterocycle in which a carbon atom on the ring is directly bonded to a nitrogen atom. In this aromatic amine, the T1 energy of the center unit is preferably smaller than the T1 energy of the antenna unit.

[0044] The aromatic amine is an aromatic amine having two or three aromatic or heterocyclic rings in which a carbon atom on the ring is directly bonded to a nitrogen atom, and it is preferred that at least one of the aromatic or heterocyclic rings in which a carbon atom on the ring is directly bonded to a nitrogen atom is an antenna unit and at least one is a center unit. The aromatic amine preferably has the following molecular structure: In the following molecular structure, a is a center unit in which the aromatic ring or heterocycle constituting the antenna unit is indicated by a thin line, and c is a center unit in which the aromatic ring or heterocycle constituting the center unit is indicated by a thick line. Note that in the following molecular structure, the structure of the aromatic ring or heterocycle is not particularly limited and is shown schematically.

[0045] [ka]

[0046] In the molecular structure shown in (i), two antenna units (a) and one center unit (c) are bonded to a nitrogen atom. The two antenna units may be the same or different. In the molecular structure shown in (ii), one antenna unit (a) and two center units (c) are bound to a nitrogen atom. The two center units may be the same or different. In the molecular structure shown in (iii), n nitrogen atoms are bonded to one n-valent center unit (c), and two antenna units (a) are bonded to each of the n nitrogen atoms. n is an integer, preferably n=1 to 10, more preferably n=1 to 6, and even more preferably n=1 to 4. The n pairs of antenna units may all be the same, or some or all may be different. Furthermore, the pair of antenna units may be the same or different.

[0047] An example of the molecule of the present invention is a molecule represented by the following general formula (I).

[0048] [ka]

[0049] In the general formula (I), n represents an integer of 1 to 10, and when n=1, R 11 represents the center unit, and R 12 represents an antenna unit, a center unit, a hydrogen atom, or any monovalent group; R 13 represents the antenna unit, and for n = 2 to 10, R 11 represents the center unit, and R 12 represents an antenna unit, a hydrogen atom, or any monovalent group; R 13 represents an antenna unit, the center unit is a substituted or unsubstituted p-terphenyl group, a substituted or unsubstituted p-quaterphenyl group, a group having a fused benzene ring of 12 to 80 carbon atoms, or a group having a fused heterocyclic ring of 12 to 80 carbon atoms, and the antenna unit is a substituted or unsubstituted biphenyl group, a substituted or unsubstituted p-terphenyl group, a substituted or unsubstituted p-quaterphenyl group, or a group having two or more fused aromatic rings or fused heterocyclic rings. In the antenna unit, the group having two or more fused aromatic rings or fused heterocyclic rings is preferably a group represented by general formula (II) described below.

[0050] (antenna unit) In the molecule of the present invention, examples of the antenna unit include an aryl group having 12 to 50 carbon atoms, preferably 12 to 40 carbon atoms, a heteroaryl group having 12 to 50 carbon atoms, preferably 12 to 40 carbon atoms, and a group having a conjugated structure that is not limited to an aromatic group. An aryl group or a heteroaryl group is preferred.

[0051] In the molecules of the present invention, at least one antenna unit preferably comprises an aromatic ring or a heterocyclic ring, more preferably two or more aromatic rings, or a combination of at least one aromatic ring and at least one heterocyclic ring. In the antenna unit, examples of the aromatic ring or heterocyclic ring include a benzene ring, a fused benzene ring, an indene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a benzosilole ring, a fluorene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, a silafluorene ring, derivatives thereof, fused aromatic rings or heterocyclic rings in which two or more rings selected from these are fused, and polycyclic aromatic rings or heterocyclic rings in which two or more rings selected from these are bonded by a single bond. The antenna unit preferably comprises a polycyclic aromatic ring in which two or more monocyclic aromatic rings are bonded by a single bond, a fused aromatic ring or fused heterocyclic ring containing at least one aromatic ring, or a derivative thereof, more preferably a fluorene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, or a silafluorene ring, and even more preferably a fluorene ring.

[0052] Examples of groups having a polycyclic aromatic ring in which two or more monocyclic aromatic rings are bonded by a single bond include a biphenyl group, a p-terphenyl group, and a p-quaterphenyl group. The bonding position of these groups having a polycyclic aromatic ring is preferably the 4-position. Furthermore, these groups having a polycyclic aromatic ring may be substituted or unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups, alkyloxy groups having 1 to 8 carbon atoms, alkylamino groups having 1 to 8 carbon atoms, and arylamino groups having 6 to 40 carbon atoms, such as diphenylamino groups. The number of substituents may be one or more, but one is preferred.

[0053] The antenna unit preferably has a fused aromatic ring or a fused heterocyclic ring containing at least one aromatic ring, more preferably has a fused ring containing two or more aromatic rings, or a fused ring containing an aromatic ring and a heterocyclic ring, still more preferably has a fused ring containing a benzene ring and a five-membered aromatic ring or heterocyclic ring, and even more preferably has a fused ring in which two benzene rings are bonded via a five-membered aromatic ring or heterocyclic ring. The heterocycle preferably contains a heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom. The heterocycle may contain one or more of these heteroatoms in combination, but preferably contains one or more single heteroatoms, and more preferably contains one heteroatom. Specific examples of the heterocycle include a pyrrole ring, a furan ring, a thiophene ring, and a silole ring.

[0054] An example of the antenna unit is a group represented by the following general formula (II).

[0055] [ka]

[0056] In general formula (II), X is a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom. When X is a carbon atom, a nitrogen atom, or a silicon atom, the hydrogen atoms bonded to the respective atoms may be substituted or unsubstituted. When X has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. R 1 and R 2 may each independently be a hydrogen atom or a monovalent group. 1 and R 2 are both hydrogen atoms, or R 1 has a monovalent group, and R 2 is a hydrogen atom. R 1 and R 2 In the formula (I), examples of the monovalent group include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group; alkyloxy groups having 1 to 8 carbon atoms; alkylamino groups having 1 to 8 carbon atoms; and arylamino groups having 6 to 40 carbon atoms, such as a diphenylamino group. R 1 and R 2 may form an aromatic ring or a heterocyclic ring. In this case, R1 and R 2 It is preferable that the ring form an indene ring structure, an indole ring structure, a benzofuran ring structure, a benzothiophene ring structure, a benzosilole ring structure, or the like. These rings may be substituted or unsubstituted, and examples of the substituent include an alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, an alkyloxy group having 1 to 8 carbon atoms, an alkylamino group having 1 to 8 carbon atoms, and an arylamino group having 6 to 40 carbon atoms such as a diphenylamino group. L is a single bond or a divalent group. The divalent group is preferably a hydrocarbon group, and may be an alkylene group having 1 to 8 carbon atoms, a cycloalkylene group having 6 to 40 carbon atoms, an arylene group having 6 to 40 carbon atoms, or a heteroarylene group having 6 to 40 carbon atoms. L is preferably a single bond, an arylene group having 6 to 40 carbon atoms, or a heteroarylene group having 6 to 40 carbon atoms. Examples of the arylene group include a phenylene group. Examples of the heteroarylene group include a fluorene-2,7-diyl group, a carbazole-2,7-diyl group, a dibenzofuran-2,7-diyl group, a dibenzothiophene-2,7-diyl group, and a silafluorene-2,7-diyl group. These aryl groups and heteroarylene groups may each be substituted or unsubstituted. * indicates the position of bonding to the nitrogen atom of the aromatic amine.

[0057] Specific examples of the antenna unit include groups containing a fluorene ring or a derivative thereof, such as a fluorenyl group, a dihydroindenofluorenyl group, a fluorenylphenyl group, a phenylfluorenyl group, a bifluorenyl group, etc. In these functional groups, the fluorene ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2-position. These functional groups may be substituted or unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl, alkyloxy groups having 1 to 8 carbon atoms, alkylamino groups having 1 to 8 carbon atoms, and arylamino groups having 6 to 40 carbon atoms, such as diphenylamino. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 7-position of the fluorene ring. In the group containing a fluorene ring or a derivative thereof, one or two of the hydrogen atoms at position 9 of the fluorene ring may be substituted or unsubstituted. When the fluorene ring has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0058] Specific examples of the antenna unit include groups containing a silafluorene ring or a derivative thereof, such as a silafluorenyl group, a dihydrobenzosilolesilafluorenyl group, a silafluorenylphenyl group, a phenylsilafluorenyl group, and a bisilafluorenyl group. In these functional groups, the silafluorene ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2-position. These functional groups may be substituted or unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups; alkyloxy groups having 1 to 8 carbon atoms; alkylamino groups having 1 to 8 carbon atoms; and arylamino groups having 6 to 40 carbon atoms, such as diphenylamino groups. The number of the substituent may be one or more, but is preferably one. The substituent is preferably introduced at the 7-position of the silafluorene ring. In a group containing a silafluorene ring or a derivative thereof, one or two of the hydrogen atoms at position 9 of the silafluorene ring may be substituted or unsubstituted. When the silafluorene ring has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0059] Specific examples of the antenna unit include groups containing a carbazole ring or a derivative thereof, such as a carbazolyl group, a dihydroindolocarbazolyl group, a carbazolylphenyl group, a phenylcarbazolyl group, and a bicarbazolyl group. In these functional groups, the carbazole ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2-position. These functional groups may be substituted or unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups; alkyloxy groups having 1 to 8 carbon atoms; alkylamino groups having 1 to 8 carbon atoms; and arylamino groups having 6 to 40 carbon atoms, such as diphenylamino groups. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 7-position of the carbazole ring. In the group containing a carbazole ring or a derivative thereof, the hydrogen atom at position 9 of the carbazole ring may be substituted or unsubstituted. When the carbazole ring has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0060] Specific examples of the antenna unit include groups containing a dibenzofuran ring or a derivative thereof, such as a dibenzofuranyl group, a dihydrobenzofuranylbenzofuranyl group, a dibenzofuranylphenyl group, a phenyldibenzofuranyl group, and a bidibenzofuranyl group. In these functional groups, the dibenzofuran ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2-position. These functional groups may be substituted or unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups; alkyloxy groups having 1 to 8 carbon atoms; alkylamino groups having 1 to 8 carbon atoms; and arylamino groups having 6 to 40 carbon atoms, such as diphenylamino groups. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 7-position of the dibenzofuran ring.

[0061] Specific examples of the antenna unit include groups containing a dibenzothiophene ring or a derivative thereof, such as a dibenzothiophenyl group, a dihydrobenzothiophenedibenzothiophenyl group, a dibenzothiophenylphenyl group, a phenyldibenzothiophenyl group, and a bidibenzothiophenyl group. In these functional groups, the dibenzothiophene ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2-position. These functional groups may be substituted or unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups; alkyloxy groups having 1 to 8 carbon atoms; alkylamino groups having 1 to 8 carbon atoms; and arylamino groups having 6 to 40 carbon atoms, such as diphenylamino groups. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 7-position of the dibenzothiophene ring.

[0062] In the above-described antenna unit, all of the hydrogen atoms may be hydrogen atoms (H), but some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0063] The chemical formula of a specific example of the antenna unit is shown below.

[0064] [ka]

[0065] [ka]

[0066] [ka]

[0067] [ka]

[0068] [ka]

[0069] [ka]

[0070] In the chemical formula of the antenna unit described above, R represents any monovalent group, such as a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. When one group contains two or more R, all of the R may be the same, or some or all of the R may be different. In addition, in the chemical formula of the antenna unit described above, all of the hydrogen atoms may be hydrogen atoms, but some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0071] (Center unit) In the molecule of the present invention, the center unit may be an aryl group having 12 to 100 carbon atoms, preferably 12 to 80 carbon atoms, a heteroaryl group having 12 to 50 carbon atoms, preferably 12 to 40 carbon atoms, or a group having a conjugated structure that is not limited to an aromatic group. An aryl group or a heteroaryl group is preferred.

[0072] In the molecules of the present invention, at least one center unit preferably comprises an aromatic ring or a heterocyclic ring, more preferably two or more aromatic rings, or a combination of at least one aromatic ring and at least one heterocyclic ring. In the center unit, examples of the aromatic ring or heterocyclic ring include a benzene ring, a fused benzene ring, an indene ring, an indole ring, a benzofuran ring, a benzothiophene ring, a benzosilole ring, a fluorene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, a silafluorene ring, derivatives thereof, fused aromatic rings or heterocyclic rings in which two or more rings selected from these are fused, and polycyclic aromatic rings or heterocyclic rings in which two or more rings selected from these are bonded by a single bond. The antenna unit preferably comprises a fused aromatic ring containing two or more aromatic rings, a polycyclic aromatic ring in which two or more monocyclic aromatic rings are bonded by a single bond, a fused heterocyclic ring containing at least one aromatic ring and at least one heterocyclic ring, or a derivative thereof, more preferably a fused aromatic ring containing two or more aromatic rings, and even more preferably a fused benzene ring. Furthermore, the antenna unit may be a group in which a monocyclic aromatic ring or heterocyclic ring, preferably a phenyl group, is introduced into such a ring structure.

[0073] Examples of groups having a fused aromatic ring containing two or more aromatic rings include a naphthyl group, a phenanthrenyl group, a benzophenanthrenyl group (a chrysenyl group), a benzoanthracenyl group (a tetraphenyl group), a triphenylenyl group, a benzo[e]pyrenyl group, a coronenyl group, a dibenzochrysenyl group, a pyrenyl group, and a hexabenzocoronenyl group. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but is preferably one.

[0074] Examples of groups having a polycyclic aromatic ring in which two or more monocyclic aromatic rings are bonded by a single bond include a p-terphenyl group, a p-quaterphenyl group, etc. Examples of groups having a fused aromatic ring and a monocyclic aromatic ring include a 2,6-diphenylnaphthyl group, etc.

[0075] Other examples of the center unit include groups having a fused heterocycle containing at least one aromatic ring and at least one heterocycle, such as a fluorene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, a silafluorene ring, or a derivative thereof. In the center unit, examples of groups having a fluorene ring or a derivative thereof include a fluorenyl group, a 2-phenylfluorenyl group, a 7-phenylfluorenyl group, and a 2,7-diphenylfluorenyl group. In these functional groups, the fluorene ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2- or 3-position. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 2- or 7-position of the fluorene ring. In the group containing a fluorene ring or a derivative thereof, one or two of the hydrogen atoms at position 9 of the fluorene ring may be substituted or unsubstituted. When the fluorene ring has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0076] In the center unit, examples of groups having a silafluorene ring or a derivative thereof include a 2-phenylfurafluorenyl group, a 7-phenylfurafluorenyl group, and a 2,7-diphenylfurafluorenyl group. In these functional groups, the furafluorene ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2- or 3-position. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 2- or 7-position of the silafluorene ring. In a group containing a furafluorene ring or a derivative thereof, one or two of the hydrogen atoms at position 9 of the furafluorene ring may be substituted or unsubstituted. When the furafluorene ring has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0077] In the center unit, examples of the group having a carbazole ring or a derivative thereof include a carbazolyl group, a 2-phenylcarbazolyl group, a 7-phenylcarbazolyl group, and a 2,7-diphenylcarbazolyl group. In these functional groups, the carbazole ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2nd or 3rd position. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 2nd or 7th position of the carbazole ring. In the group containing a carbazole ring or a derivative thereof, the hydrogen atom at position 9 of the carbazole ring may be substituted or unsubstituted. When the carbazole ring has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl.

[0078] In the center unit, examples of the group having a dibenzofuran ring or a derivative thereof include a dibenzofuranyl group, a 2-phenyldibenzofuranyl group, a 7-phenyldibenzofuranyl group, and a 2,7-diphenyldibenzofuranyl group. In these functional groups, the dibenzofuran ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2nd or 3rd position. Furthermore, these functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When the dibenzofuran has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but one is preferred. The substituent is preferably introduced at the 2- or 7-position of the dibenzofuran ring.

[0079] In the center unit, examples of the group having a dibenzothiophene ring or a derivative thereof include a dibenzothiophenyl group, a 2-phenyldibenzothiophenyl group, a 7-phenyldibenzothiophenyl group, and a 2,7-diphenyldibenzothiophenyl group. In these functional groups, the dibenzothiophene ring is preferably bonded to the nitrogen atom of the aromatic amine at the 2- or 3-position. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. The number of substituents may be one or more, but is preferably one. The substituent is preferably introduced at the 2- or 7-position of the dibenzothiophenyl ring.

[0080] When the aromatic amine is disubstituted, the center unit is preferably a divalent functional group in which two carbon atoms on a polycyclic aromatic ring or heterocyclic ring formed by combining an aromatic ring and / or a heterocyclic ring are directly bonded to nitrogen atoms of the aromatic amine. The disubstituted aromatic amine has the above molecular structure (iii) where n=2. Examples of the group having a divalent fused aromatic ring include a naphthylene group, a phenanthrenylene group, a benzophenanthrenylene group, a triphenylenylene group, a benzo[e]pyrenylene group, a coronenylene group, and a pyrenylene group. Other examples of the group having a divalent polycyclic aromatic ring include a 4,4''-p-terphenylene group and a 4,4''-p-quaterphenylene group. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but is preferably one.

[0081] Examples of the group having a divalent fused heterocycle having an aromatic ring and a heterocycle include a fluorene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, a silafluorene ring; a 2,2'-bifluorene ring, a 2,2'-carbazole ring, a 2,2'-dibenzofuran ring, a 2,2'-dibenzothiophene ring, a 2,2'-silafluorene ring; a dihydroindenofluorene ring, a dihydroindolocarbazole ring, a dihydrobenzofurandibenzofuran ring, a dihydrobenzothiophenedibenzothiophene ring, a dihydrobenzosilolesilafluorene ring; a benzodifuran ring, a benzodithiophene ring, or a derivative thereof, and a divalent functional group in which two of the carbon atoms on the ring are directly bonded to the nitrogen atom of the aromatic amine is preferred. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but is preferably one.

[0082] When the aromatic amine is trisubstituted, the center unit is preferably a trivalent functional group in which three carbon atoms on a polycyclic aromatic ring or heterocyclic ring formed by combining an aromatic ring and / or a heterocyclic ring are directly bonded to nitrogen atoms of the aromatic amine. The trisubstituted aromatic amine has the above molecular structure (iii) where n=3. The trivalent group having an aromatic ring and / or a heterocyclic ring is preferably a trivalent functional group in which three of the carbon atoms on the ring are directly bonded to the nitrogen atom of the aromatic amine, such as a naphthalene ring, a phenanthrene ring, a triphenylene ring, a coronene ring, a truxene ring, a 10,15-dihydro-5H-diindolo[3,2-a:3',2'-c]carbazole ring, a 10,15-dihydro-5H-dibenzosilole[3,2-a:3',2'-c]silafluorene ring, or a derivative thereof. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but is preferably one.

[0083] When the aromatic amine is tetra- or more substituted, the center unit is preferably a tetravalent or higher group in which four or more carbon atoms on a polycyclic aromatic ring or heterocycle formed by combining aromatic rings and / or heterocycles are directly bonded to an aromatic nitrogen atom, and is preferably a tetravalent or higher group having a fused aromatic ring. For example, a tetra-substituted aromatic amine has the above molecular structure (iii) where n=4. The tetravalent or higher valent group having an aromatic ring preferably has a cyclic structure such as a coronene ring or a hexabenzobenzene ring. These functional groups may be substituted or unsubstituted, but are preferably unsubstituted. When substituted, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. The number of substituents may be one or more, but is preferably one.

[0084] In the center unit described above, all of the hydrogen atoms may be hydrogen atoms, but some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0085] Specific examples of the center unit in the molecule of the present invention are shown below.

[0086] [ka]

[0087] [ka]

[0088] Specific examples of the center unit in the disubstituted aromatic amine are shown below. [ka]

[0089] [ka]

[0090] Specific examples of the center unit in the trisubstituted aromatic amine are shown below. [ka]

[0091] Specific examples of the center unit in the tetrasubstituted aromatic amine are shown below. [ka]

[0092] In the chemical formula of the center unit above, R represents any monovalent group, such as a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. When one group contains two or more R, all of the R may be the same, or some or all of the R may be different. In addition, in the chemical formula of the center unit described above, all of the hydrogen atoms may be hydrogen atoms, but some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0093] Specifically, the molecule of the present invention is preferably an aromatic amine in which at least one selected from the above-mentioned antenna units and at least one selected from the above-mentioned center units are directly bonded to the nitrogen atom, and particularly, an aromatic amine in which two antenna units and one center unit are directly bonded to the nitrogen atom is preferred. As the antenna unit, a group having a fluorene ring, a carbazole ring, a dibenzofuran ring, a dibenzothiophene ring, a silafluorene ring, or a derivative thereof, in which the carbon atom at the 2nd position on the ring is directly bonded to a nitrogen atom, can be preferably used. The center unit is preferably a fused aromatic ring consisting of only benzene rings, more preferably a fused aromatic ring consisting of two or three rings, and more specifically, a 1-naphthyl group or a 3-phenanthrene group is preferred.

[0094] Preferably, the molecules of the present invention are represented by the following general formula (III): [ka]

[0095] More preferably, the molecule of the present invention is represented by the following general formula (IV): [ka]

[0096] More preferably, the molecule of the present invention is represented by the following general formula (V): [ka]

[0097] In the general formulae (III) to (V), X and R 1 , R 2, L are the same moieties as those in the general formula (I) and the general formula (II), and are as explained above. 1’ , R 2’ , L' are also common moieties to the general formula (I) and general formula (II) above, as explained above. R centre is a group representing a center unit, which can be selected from the center units described above. centre A preferred example of is a 1-naphthyl group or a 3-phenanthrene group. In the general formulas (III) and (V), X, R 1 , R 2 , L and X', R 1’ , R 2’ and L' may be the same or different. In general formula (IV), R is a hydrogen atom or any monovalent group, and the any monovalent group is preferably an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. In general formula (IV), all of the R may be the same, or some or all of the R may be different. In the above general formulas (III) to (V), all of the hydrogen atoms may be hydrogen atoms, but some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0098] More specifically, the molecules of the present invention include compounds represented by the following structural formulas (VI) to (X): In these compounds, all of the hydrogen atoms may be hydrogen atoms, or some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0099] [ka] [ka]

[0100] The synthesis method of the molecule of the present invention is not particularly limited, and the molecule of the present invention can be synthesized by appropriately combining known synthesis methods and conditions. For example, the compound can be synthesized by reacting a compound having an antenna unit with a compound having a center unit. More specifically, the compound can be synthesized by reacting a halide of the antenna unit with an amine compound having a center unit. The amine compound having a center unit may be a primary amine having one center unit or a secondary amine having two center units. For example, as a molecule of the present invention, a molecule in which n=1 in the above general formula (I) can be synthesized according to the following chemical formula.

[0101] [ka]

[0102] In the above formula, R 11 represents the center unit, and R 12 represents an antenna unit, a center unit, a hydrogen atom, or any monovalent group; R 13 represents the antenna unit. R 11 , R 12 , and R 13 is a group corresponding to the case where n=1 in the above general formula (I), and the details are as explained above. Z represents a halogen atom other than a fluorine atom, and is preferably Cl, Br, or I.

[0103] The reaction may be carried out in the presence of an additive such as a catalyst. The reaction may be carried out at, but not limited to, 80 to 180°C for 1 to 74 hours. Optionally, the resulting compound may be deuterated by treatment with heavy water.

[0104] "Dark light material" The light-storage material according to the present invention preferably contains the above-mentioned luminescent material. The luminescent material is preferably present in an amount of 0.001% by mass to 30% by mass relative to the total amount of the light-storage material. This light-storage material is preferably a solid light-storage material, for example, a solid light-storage material in which the luminescent material is dispersed in a solid medium. The light-storage material may contain a single luminescent material or a combination of two or more luminescent materials.

[0105] The light-storing material may contain a light-emitting material and a host material. The light-storing material preferably contains a light-emitting material and the host material as the remainder. The light-storing material may contain other additives in addition to the light-emitting material and the host material.

[0106] In order for the light-storing material of the present invention to exhibit high light-storage efficiency, it is important to confine the triplet excitons generated in the light-emitting material within the light-emitting material. Therefore, it is preferable to use a host material in addition to the light-storing material. As the host material, an organic compound having a T1 energy higher than the T1 energy of the light-emitting material of the present invention can be used. As a result, it is possible to confine the triplet excitons generated in the light-emitting material of the present invention within the molecules of the light-emitting material of the present invention, thereby fully utilizing the light-storage efficiency of the light-emitting material. However, even if the T1 energy of the host material is equivalent to that of the light-emitting material of the present invention, if the host material has a low triplet exciton diffusion ability, it is still possible to confine the triplet excitons generated in the light-emitting material of the present invention within the molecules of the light-emitting material of the present invention, and it can be used in the present invention without any particular restrictions.

[0107] When a host material is used, the amount of the light-emitting material is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more, relative to the total amount of the phosphorescent material, and is preferably 30% by mass or less, more preferably 10% by mass or less, and even more preferably 3% by mass or less. The host material in the light-storing material is preferably an organic compound that has hole transporting ability and electron transporting ability, prevents the wavelength of emitted light from becoming longer, and has a high glass transition temperature.

[0108] Specific examples of compounds that can be used as host materials are listed below. Among these, we have selected compounds that are difficult for oxygen from the atmosphere to penetrate and have k Q Compounds (H1) and (H5) are preferred because (RT) is small and the phosphorescent function can be obtained more satisfactorily.

[0109] [ka]

[0110] The luminous material of the present invention can be used for various purposes, such as indicator lights for nighttime or dark places, security media for preventing counterfeiting, bioimaging, etc. The display medium of the present invention has a layer containing the above-described luminescent material of the present invention. The display medium having a layer containing the luminescent material of the present invention formed thereon emits light when irradiated with excitation light, and continues to emit light at high brightness at room temperature even after irradiation with excitation light. Therefore, it can be preferably used for security purposes such as anti-counterfeiting. It can also be used for decorating building materials such as wallpaper.

[0111] The particles of the present invention preferably contain the above-described luminous material of the present invention and have an average particle size of 10 μm or less. As described above, the particulate luminous material is preferably a solid luminous material containing a light-emitting material and a host material. This particulate luminous material may be provided as a powder, or may be provided as a composition dispersed in an aqueous medium or an oil-based medium. Applications of the particulate luminous material include inks, etc. The ink using the luminous material of the present invention is preferably a composition in which the luminous material is dispersed in a medium. By using this ink to decorate a substrate, a luminous image can be formed. Furthermore, the particulate luminous material of the present invention can be preferably used for bioimaging applications.

[0112] "New compound" The present invention can provide a novel compound represented by the following general formula (III). [ka]

[0113] In general formula (I), X is a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, or a silicon atom. When X is a carbon atom, a nitrogen atom, or a silicon atom, the hydrogen atoms bonded to the respective atoms may be substituted or unsubstituted. When X has a substituent, examples of the substituent include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. R 1 and R 2 may each independently be a hydrogen atom or a monovalent group. 1 and R 2 are both hydrogen atoms, or R 1 has a monovalent group, and R 2 is a hydrogen atom. R 1 and R 2 In the formula (I), examples of the monovalent group include alkyl groups having 1 to 8 carbon atoms, such as a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group; alkyloxy groups having 1 to 8 carbon atoms; alkylamino groups having 1 to 8 carbon atoms; and arylamino groups having 6 to 40 carbon atoms, such as a diphenylamino group. R 1 and R 2 may form an aromatic ring or a heterocyclic ring. In this case, R 1 and R 2 It is preferable that the ring form an indene ring structure, an indole ring structure, a benzofuran ring structure, a benzothiophene ring structure, a benzosilole ring structure, or the like. These rings may be substituted or unsubstituted, and examples of the substituent include an alkyl group having 1 to 8 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group, an alkyloxy group having 1 to 8 carbon atoms, an alkylamino group having 1 to 8 carbon atoms, and an arylamino group having 6 to 40 carbon atoms such as a diphenylamino group. L is a single bond or a divalent group. The divalent group is preferably a hydrocarbon group, and may be an alkylene group having 1 to 8 carbon atoms, a cycloalkylene group having 6 to 40 carbon atoms, an arylene group having 6 to 40 carbon atoms, or a heteroarylene group having 6 to 40 carbon atoms. L is preferably a single bond, an arylene group having 6 to 40 carbon atoms, or a heteroarylene group having 6 to 40 carbon atoms. Examples of the arylene group include a phenylene group. Examples of the heteroarylene group include a fluorene-2,7-diyl group, a carbazole-2,7-diyl group, a dibenzofuran-2,7-diyl group, a dibenzothiophene-2,7-diyl group, and a silafluorene-2,7-diyl group. These aryl groups and heteroarylene groups may each be substituted or unsubstituted. X', R 1’ , R 2’ , L' are the above-mentioned X and R 1 , R 2 , L, and X, R 1 , R 2 , L and X', R 1’ , R 2’ , L' may be the same or different from each other. R centre is a group representing a center unit, and is a substituted or unsubstituted p-terphenyl group, a substituted or unsubstituted p-quaterphenyl group, a group having a fused benzene ring with 12 to 80 carbon atoms, or a group having a fused heterocyclic ring with 12 to 80 carbon atoms. centre is preferably a group having a fused benzene ring with 12 to 80 carbon atoms, more preferably a group having a fused benzene ring with 12 to 4 carbon atoms, and even more preferably a 1-naphthyl group or a 3-phenanthrene group. In the above general formula (III), all of the hydrogen atoms may be hydrogen atoms, but some or all of the hydrogen atoms may be substituted with heavy hydrogen (deuterium D).

[0114] More preferably, the novel compound of the present invention is represented by the following general formula (IV): [ka]

[0115] In general formula (IV), R 1 , R 2 , R 1’ , R 2’ , and R centre are the same groups as those in the general formula (III) above, as described above. R is a hydrogen atom or any monovalent group, and the monovalent group is preferably an alkyl group having 1 to 8 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. In the general formula (IV), all of the R may be the same, or some or all of the R may be different. R may be heavy hydrogen (deuterium D) or a group substituted with heavy hydrogen.

[0116] More preferably, the novel compound of the present invention is represented by the following general formula (V): [ka]

[0117] In general formula (V), R centre is a group common to the general formula (III) above, and is as described above.

[0118] More specifically, the novel compounds of the present invention include compounds represented by the following structural formulas (VI) to (X): In these compounds, all of the hydrogen atoms may be hydrogen atoms, or some or all of the hydrogen atoms may be substituted with deuterium (D).

[0119] [ka] [ka]

[0120] The novel compound of the present invention can be preferably used for a light-emitting material having a high brightness of afterglow at room temperature and a phosphorescent material using the same. The novel compounds of the present invention preferably have the following properties: The novel compound of the present invention has an optimized structure of the lowest excited triplet state T1, and a higher singlet excited state S n and the ground state S0, the transition dipole moment (μ Sn-S0 ), S n and T1, the spin-orbit interaction (SOC Sn-T1 ), and S n and T1 (E Sn-T1 ), P n =μ Sn-S0 SOC Sn-T1 / E Sn-T1 When we define n P n ) 2 is 4.00 x 10 -7 D 2 In this definition, the novel compound of the present invention is a compound having a spin-orbit interaction (SOC) between T1 and S0. T1-S0 ) squared is 1×10 1 cm -2 It is preferable that:

[0121] The novel compound of the present invention has an oscillator strength (f S1-S0 ) is preferably 0.2 or less. The novel compound of the present invention has an energy difference between S1 and T1 (E S1-T1 ) is preferably 0.2 eV or more.

[0122] Other Embodiments As described above, the light-emitting material of the present invention has a structure in which (Σ n P n ) 2 is 4.00 x 10 -7 D 2 That is all, and the spin-orbit interaction (SOC) between T1 and S0 T1-S0 ) squared is 1×10 1 cm -2or less, and the oscillator strength (f S1-S0 ) is preferably 0.2 or less. Furthermore, the light-emitting material of the present invention preferably has the above-mentioned molecular structure.

[0123] The light-emitting material of the present invention is a material that exhibits spin-orbit interaction (SOC) between T1 and S0. T1-S0 ) squared is 1×10 1 cm -2 By being less than or equal to k nr (RT) becomes smaller, and the light-storing efficiency can be improved. T1-S0 The square of can be made smaller by substituting deuterium for hydrogen atoms in the above molecular structure. Note that the luminescent material of the present invention can be a compound that is not substituted with deuterium in the above molecular structure, even if it is a compound that is not substituted with deuterium. T1-S0 The square of is small enough.

[0124] Specific examples of the luminescent material of the present invention that is substituted with deuterium include compounds represented by the structural formulas (VI) to (X) above in which some or all of the hydrogen atoms have been substituted with deuterium. It is sufficient that deuterium is contained in at least one of the antenna unit and the center unit, and deuterium may be contained in both the antenna unit and the center unit. For example, all of the hydrogen atoms in the antenna unit and the center unit may be substituted with deuterium, all of the hydrogen atoms in the antenna unit may be substituted with deuterium so that the center unit does not contain deuterium, or all of the hydrogen atoms in the center unit may be substituted with deuterium so that the antenna unit does not contain deuterium.

[0125] In another aspect of the present invention, the luminescent material preferably has a molecular structure in the lowest excited triplet state T1 optimized by density functional theory using the functional B3LYP and basis set 6-31G(d), and the optimized structure is used to calculate formula (11) by density functional theory using the functional PBE0 and basis set TZP, such that the luminescent material has a molecular structure that is 100 times or less the value of compound (12).

number

[0126] In equation (11), Q p is the molecular configuration in the p-th vibrational mode in the optimized structure of T1, P(T) is the vibration factor, FC is the Franck-Condon factor between T1 and S0, and H SO is a Hamiltonian corresponding to the spin-orbit interaction. More specifically, Equation (11) is defined as in Non-Patent Document IV: S. Hirata, I. Bhattacharjee, J. Phys. Chem. A 2021, 125, 885-894.

[0127] By using the above formula (11), in the non-deuterated molecular structure, SOC T1-S0 The square of is 1×10 1 cm -2 By: nr Compared with the estimation of (RT), k is more accurate. nr This makes it possible to estimate the value of (RT), and identify molecular structures with high light-storing efficiency. That is, a light-emitting material for which the value calculated using formula (11) is 100 times or less the value of compound (12) exhibits higher light-storing efficiency. More preferably, the value calculated using formula (11) is 50 times or less, 20 times or less, 10 times or less, 5 times or less, or 3 times or less the value of compound (12).

[0128] Examples of such compounds include compounds having the following center unit structures from among the molecular structures described above: In the aromatic amine, the antenna unit combined with the following center unit is not particularly limited and may have any of the antenna unit structures described above. [ka]

[0129] A more preferable structure of the center unit is shown below. [ka]

[0130] More specifically, the compounds having a value calculated by formula (11) that is 100 times or less than that of compound (12) include the following compounds. More preferred are compounds represented by the following structure (VIII) or (IX).

[0131] [ka]

[0132] In yet another aspect of the present invention, the luminescent material preferably comprises a compound in which the value calculated by the above formula (11) is 100 times or less than the value for compound (12), and in which some or all of the hydrogen atoms have been substituted with deuterium (deuterium D). As described above, when not substituted with deuterium, a compound whose value when calculated using formula (11) above is 100 times or less than the value of compound (12) can improve the light-storing efficiency. However, by further deuterizing this compound, the light-storing efficiency can be further improved. [Example]

[0133] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. "Manufacturing example A" Example 1 Dye 1 represented by the following structure 1 was synthesized by the following method.

[0134] [ka]

[0135] 1-Bromonaphthalene (200 mg), di(9H-fluoren-2-yl)amine (333 mg), tris(dibenzylideneacetone)dipalladium (8.8 mg), sodium t-butoxide (92 mg), tri-t-butylphosphine (3.88 mg), and anhydrous toluene (3 mL) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was removed, dehydrated over sodium sulfate, and purified by column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to yield a yellow powder (328 mg, 0.70 mmol, 72%). 1 H NMR (DMSO-D6, 500 MHz): δ 8.03 (d, 1 H, J = 10 Hz), 7.96 (d, 1 H, J = 10 Hz), 7.92 (d, 1 H, J = 10 Hz), 7.76-7.73 (m, 4 H), 7.59 (t, 1 H, J = 10 Hz), 7.53-7.48 (m, 3 H), 7.42 (t, 3 H, J = 10 Hz), 7.32 (t, 2 H, J = 10 Hz), 7.22 (t, 2 H, J = 10 Hz), 7.14 (s, 2 H), 7.03 (d, 1 H, J = 10 Hz), 3.78 (s, 4H) ppm; 13 C NMR (CDCl3, 125 MHz): δ 148.20, 144.76, 143.11, 141.76, 135.94, 135.48, 131.32, 128.54, 127.20, 126.87, 126.54, 126.51, 126.37, 126.30, 125.88, 124.99, 124.58, 121.38, 120.48, 119.31, 119.06, 37.06 ppm; HRMS (m / z): [M] + calcd. for C 35 H 25 N, 471.1987; found, 471.19884; analysis (calcd., found for C 35 H 25N): C (91.69, 91.82), H (5.34, 5.26), N (2.97, 2.58). 150 mg of this yellow powder, 150 mg of 10% palladium carbon, and 30 ml of heavy water were placed in a 50 ml Teflon (registered trademark) container-mounted autoclave and reacted for 12 hours at 250°C and 4-5 MPa. After cooling the reaction solution to room temperature, it was extracted with ethyl acetate and water, the organic layer was dried over sodium sulfate, and then purified using column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to obtain dye 1 powder (120 mg). The deuteration rate was confirmed by 1H NMR and was found to be 95.7%.

[0136] 99.7 wt% β-estradiol (manufactured by Tokyo Chemical Industry Co., Ltd.) shown in Structure 2 below and 3 wt% dye 1 were weighed into a glass bottle and heated to 220°C to dissolve dye 1 in the β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce Sample 1, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. The irradiance of Sample 1 at 360 nm was approximately 0.04 mW / cm 2 The quantum yield of the afterglow at room temperature (Φ DE t=0.02-1 The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 20.3%. Next, using a 360 nm constant-wave laser (UV-FN-360, 100 mW, CNI, China) as the excitation light and a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) as the photodetector, the intensity of the 360 nm excitation light was varied, and the change in the luminescence intensity at room temperature observed from sample 1 was measured between 0.02 and 1 s after the excitation light irradiation was stopped.

[0137] [ka]

[0138] (Comparative Example 1) EU 2+ and Dy3+ Powder of SrAl2O4 (manufactured by Nemoto Special Chemical Co., Ltd., G300-FF) doped with Zn was used as sample 2, and Φ was measured in the atmosphere at room temperature using 360 nm excitation light. DE t=0.02-1 The RT (time-resolved photoluminescence) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 0.8%. Next, using a 360 nm constant-wave laser (UV-FN-360, 100 mW, CNI, China) as the excitation light and a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) as the photodetector, the intensity of the 360 nm excitation light was varied, and the change in the luminescence intensity at room temperature observed from sample 2 was measured between 0.02 and 1 s after the excitation light irradiation was stopped.

[0139] (Comparative Example 2) 99 wt% 2,8-bis(diphenylphosphoryl)dibenzo[b,d]thiophene (PPT) (manufactured by Luminescence Technology Inc.) represented by the following structure 3 and 1 wt% dye 2 (manufactured by Tokyo Chemical Industry Co., Ltd.) represented by the following structure 4 were weighed into a glass bottle and heated to 250°C under a nitrogen atmosphere to dissolve dye 2 in the PPT. The liquid was sandwiched between two quartz substrates heated to 250°C on a hot plate. The two quartz substrates were sealed with epoxy resin under a nitrogen atmosphere and then rapidly cooled to room temperature to produce sample 3, in which the material was sandwiched between two quartz substrates to a thickness of approximately 10 μm. Φ of sample 3 in air at room temperature using 360 nm excitation light DE t=0.02-1 The RT (time-resolved photoluminescence) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 0.5%. Next, using a 360 nm constant-wave laser (UV-FN-360, 100 mW, CNI, China) as the excitation light and a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) as the photodetector, the intensity of the 360 nm excitation light was varied, and the change in the room temperature luminescence intensity observed from sample 3 was measured between 0.02 and 1 s after the excitation light irradiation was stopped.

[0140] [ka]

[0141] [ka]

[0142] (Comparative Example 3) Dye 3 represented by the following structure 5 was synthesized by the following method.

[0143] [ka]

[0144] 1-Bromonaphthalene (200 mg), diphenylamine (164 mg), tris(dibenzylideneacetone)dipalladium (8.8 mg), sodium t-butoxide (92 mg), tri-t-butylphosphine (3.88 mg), and anhydrous toluene (3 mL) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was removed, dehydrated with sodium sulfate, and purified by column chromatography (silica gel: ethyl acetate / hexane; 2 / 98 vol) to yield a white powder (218 mg, 0.74 mmol, 76%). 1 H NMR (DMSO-D6, 500 MHz): δ 8.01 (d, 1H, J = 10 Hz), 7.90 (d, 1H, J = 10 Hz), 7.85 (d, 1H, J = 10 Hz), 7.57 (d, 1H, J = 10 Hz), 7.51 (t, 1H, J = 10 Hz), 7.42 (t, 1H, J = 10 Hz), 7.35 (d, 1H, J = 10 Hz), 7.24-7.21 (m, 4H), 6.95-6.91 (m, 6H) ppm; 13C NMR (DMSO-D6, 125 MHz): δ 147.82, 142.73, 134.95, 130.65, 129.34, 129.18, 128.58, 127.28, 126.68, 126.31, 123.47, 121.72, 121.24, 121.11 ppm; HRMS (m / z): [M] + calcd. for C 22 H 17 N, 295.1361; found, 295.13939; analysis (calcd., found for C 22 H 17 N): C (89.46, 89.44), H (5.80, 5.80), N (4.74, 4.76).

[0145] 99.7 wt% β-estradiol and 0.3 wt% dye 3 were weighed into a glass bottle and heated to 220°C to dissolve dye 3 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 4, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 4 in room temperature air using 360 nm excitation light was measured. DE t=0.02-1 The (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 1.8%.

[0146] The photophysical factors of Example 1 and Comparative Examples 1 to 3 are summarized in Table 1.

[0147] The light-storing material using room-temperature phosphorescence in Example 1 had a higher light-emitting yield (Φ DE t=0.02-1s ) is several tens of times larger. Therefore, when the samples have the same optical absorption, the sample of Example 1 exhibits several tens of times the brightness of the samples of Comparative Examples 1 to 3.

[0148] [Table 1]

[0149] FIG. 5 is a graph showing the relationship between the intensity of 360 nm excitation light and the average luminescence intensity from 0.02 seconds to 1.0 seconds after the irradiation of excitation light was stopped in Example 1 and Comparative Examples 1 and 2. As shown in Figure 5, in Example 1, when the absorbance is the same, the luminance is significantly improved as the excitation light intensity increases compared to Comparative Examples 1 and 2. In the phosphorescent materials of Comparative Examples 1 and 2, the luminance is significantly improved as the excitation light intensity increases. 2 At excitation light intensities above 100 mW / cm, the brightness increase saturates and there is almost no increase in brightness. 2 When an excitation light intensity of about 1000 nm is used, the phosphorescent brightness of Example 1 is 1000 times or more that of Comparative Examples 1 and 2. From the above, it can be seen that while the phosphorescent brightness of existing phosphorescent materials can only be seen in the dark, the highly efficient room-temperature phosphorescent phosphorescent material of the present invention achieves a phosphorescent brightness that can be seen even in bright environments.

[0150] "Manufacturing example B" Example 2 99.7 wt% β-estradiol and 0.3 wt% dye 1 were weighed into a glass bottle and heated to 220°C to dissolve dye 1 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 5, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 5 during irradiation of 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and was found to be 75%. P (RT) was measured in the atmosphere and was found to be 50%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ under 360 nm excitation light for sample 5. PThe RT (Resolution Time) was measured and found to be 1.0 seconds. The emission spectrum of Sample 5 during irradiation with 360 nm excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured using an absolute PL quantum yield analyzer (Hamamatsu Photonics, C9920-02G). The results are shown in the upper part of Figure 6. The peak wavelength (λ P ) was 550 nm. Furthermore, from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light (the dotted line in the lower part of Figure 6) and the rising energy of the room temperature phosphorescence spectrum (the dotted line in the upper part of Figure 6), E S1-T1 was determined to be 0.63 eV.

[0151] Next, the intersystem crossing yield (Φ) of dye 1 from the S1 to the triplet state in benzene at room temperature was measured by the method described in Non-Patent Document (I). ISC (RT)) was measured and found to be 89%, which is almost 100-Φ F The determined Φ was roughly equivalent to the % value. P (RT), Φ ISC (RT), τ P (RT) into the following equation (I) to obtain the phosphorescence rate constant (k P ) was calculated to be 0.63s -1 It was. Φ P (RT)=Φ ISC (RT)τ P (RT)k P (I) τ P (RT)=k P / (k P +k NR (RT)+k Q (RT)) (II)

[0152] where k NR (RT) is the rate constant of deactivation due to the intramolecular vibration of the dye from T1, and k Q (RT) is the rate constant for inactivation of the dye by intermolecular energy transfer from T1. Next, τ of sample 5 P When measured from 77K to 400K, the results are as shown in Figure 7. P Using kNR +k Q The temperature dependence of was plotted as shown in Figure 8. The graph in Figure 8 was fitted with two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is k NR As derived from k NR (RT) and k Q (RT) was separated and found to be 0.24 s -1 and 0.085s -1 Next, the fluorescence lifetime (τ F The fluorescence rate constant (k F ) to k F =Φ F (RT) / τ F (RT) was determined to be 1.0 × 10 8 s -1 It was.

[0153] Non-patent literature (I): R. Huang, J. Avo, T. Northey, E. Chaning-Pearce, PL dos Santos, JS Ward, P. Data, MK Etherington, MA Fox, TJ Penfold, MN Berberan-Santos, JC Lima, MR Bryce, FB Dias, J. Mater. Chem. C 2017, 5, 6269.

[0154] The optimized structure of dye 1 in the lowest singlet excited state (S1) was determined using Gaussian09 with density functional theory (DFT) and the functional B3LYP and the basis set 6-31G(d). This optimized structure was then used to determine the optimal structure of dye 1 in the lowest singlet excited state (S1) using Amsterdam DFT (ADF2018 package) with the functional PBE0 and the basis set TZP. S1-S0The calculated value was 0.017. Next, the optimized structure of T1 of dye 1 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.59s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 1.12 × 10 -6 D 2 and 6.29 x 10 -1 cm -2 It was.

[0155] In addition, for the skeletons of the antenna unit of dye 1 shown in Structure 6 below and the center unit of dye 1 shown in Structure 7 below, the optimized structure of S0 was calculated using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set, and the T1 energy was calculated using the same functional and basis set. As a result, the T1 energies of the antenna unit and center unit were 2.90 eV and 2.62 eV, respectively, confirming that the T1 energy of the center unit was smaller than that of the antenna unit.

[0156] [ka]

[0157] [ka]

[0158] Example 3 Dye 4, represented by the following structure 8, was synthesized by the following method.

[0159] [ka]

[0160] 3-Bromophenanthrene (200 mg), di(9H-fluoren-2-yl)amine (268 mg), tris(dibenzylideneacetone)dipalladium (7.14 mg), sodium t-butoxide (75 mg), tri-t-butylphosphine (3.15 mg), and anhydrous toluene (3 mL) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was dehydrated over sodium sulfate and purified by column chromatography (silica gel: ethyl acetate / hexane; 5 / 95 vol) to give a yellow powder (323 mg, 0.62 mmol, 80%). 1 H NMR (DMSO-D6, 500 MHz): δ 8.39-8.29 (m, 2 H), 7.99-7.70 (m, 8 H), 7.63-7.4 9 (m, 4 H), 7.45-7.32 (m, 5 H), 7.30-7.17 (m, 4 H), 3.88 (s, 4 H) ppm; 13 C NMR (DMSO-D6, 125 MHz): δ 147.38, 144.71, 142.63, 140.18, 135.21, 132.82, 131.19, 129.06, 128.67, 128.13, 127.69, 127.22, 127.11, 126.75, 126.32, 125.78, 124.79, 124.43, 124.34, 123.64, 122.91, 121.65, 120.71, 120.03, 119.58, 118.59, 36.47 ppm; HRMS (m / z): [M] + calcd. for C 40 H 27 N, 521.2143; found 521.21202; analysis (calcd., found for C 40 H 27 N): C (92.10, 92.13), H (5.22, 5.28), N (2.69, 2.59). 150 mg of this yellow powder, 100 mg of 10% palladium carbon, and 30 ml of heavy water were placed in a 50 ml Teflon (registered trademark) container-mounted autoclave and reacted for 12 hours at 250°C and 4-5 MPa. After cooling the reaction solution to room temperature, it was extracted with ethyl acetate and water. The organic layer was dried over sodium sulfate and then purified using column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to obtain dye 4 powder (75 mg). The deuteration rate was confirmed using 1H NMR and was found to be 87.3%.

[0161] 99.7 wt% β-estradiol and 0.3 wt% dye 4 were weighed into a glass bottle and heated to 220°C to dissolve dye 4 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 6, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 6 during irradiation with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 68%. P (RT) was measured in the atmosphere and was 46%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ P The time to response (RT) was measured to be 1.4 seconds.

[0162] For sample 6, an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) was used to measure the emission spectrum during irradiation with 360 nm excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light was stopped. P Furthermore, using the same method as in Example 2, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum.S1-T1 was determined to be 0.58 eV.

[0163] Next, the Φ of dye 4 in benzene was obtained by the method described in Non-Patent Document (I). ISC (RT) was measured and found to be 68%, which is almost 100-Φ F The determined value of Φ was equivalent to that of %. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.44s -1 Next, the τ of sample 6 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of was created. The graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is k NR As a result of the room temperature k NR (RT) and k Q (RT) was separated and was 0.20 s -1 and 0.062s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F (RT) was measured to be 3.1 ns. F k F =Φ F (RT) / τ F (RT) was determined to be 7.1 × 10 7 s -1 It was.

[0164] Using Gaussian09, the optimized structure of dye 4 at S1 was determined by DFT using B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0The calculated value was 0.056. Next, the optimized structure of T1 of dye 4 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.53s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 When calculated, each was 1.00 × 10 -6 D 2 and 2.83 x 10 -1 cm -2 It was.

[0165] Furthermore, for the antenna unit of dye 4 shown in Structure 6 and the center unit of dye 4 shown in Structure 9 below, the optimized S0 structure was calculated using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set, and the T1 energy was calculated using the same functional and basis set. As a result, the T1 energies of the antenna unit and center unit were 2.90 eV and 2.63 eV, respectively, confirming that the T1 energy of the center unit was smaller than that of the antenna unit.

[0166] [ka]

[0167] Comparative Example 4 99.7 wt% β-estradiol and 0.3 wt% dye 5 (manufactured by Tokyo Chemical Industry Co., Ltd.) represented by the following structure 10 were weighed into a glass bottle and heated to 220°C to dissolve dye 5 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 7, in which the material was sandwiched between two quartz substrates to a thickness of approximately 10 μm. Φ of sample 7 during irradiation with 360 nm excitation light PLThe absolute PL quantum yield was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and was found to be 89%. P When measured in the atmosphere, the value was 3.7%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P (RT) was used to determine the value as 85%. In addition, the emission spectrum during the excitation light irradiation and the phosphorescence spectrum immediately after the excitation light irradiation were measured, and λ P Furthermore, using the same method as in Example 2, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum. S1-T1 Next, τ was measured under 360 nm excitation light using a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12). P The time was measured to be 0.77 seconds.

[0168] [ka]

[0169] Next, the Φ of dye 5 in benzene was determined by the method described in Non-Patent Document (I). ISC (RT) was measured and found to be 26%, which is almost 100-Φ F The determined value of Φ was equivalent to that of %. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k P The calculated result was 0.33s -1 Next, the τ of sample 7 P was measured from 77K to 400K. P Using k NR +k Q A graph of the temperature dependence of was created. The graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is kNR As derived from k NR (RT) and k Q (RT) was separated and found to be 0.92 s -1 and 0.23s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F (RT) was measured to be 1.1ns. F k F =Φ F (RT) / τ F (RT) was determined to be 77 × 10 7 s -1 It was.

[0170] The optimized structure of dye 5 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 1.149. Next, the optimized structure of T1 of dye 5 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.37s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated, and the results were 8.14 × 10 -7 D 2 and 5.86 x 10 -1 cm -2 It was.

[0171] (Comparative Example 5) 99.7 wt% β-estradiol and 0.3 wt% dye 6 (manufactured by Aldrich) represented by the following structure 11 were weighed into a glass bottle and heated to 220°C to dissolve dye 6 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 8, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 8 during irradiation with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 17%. P When measured in the atmosphere, the value was 0.91%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P (RT) was used to determine the value as 16%. In addition, the emission spectrum during irradiation with excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured, and λ P Furthermore, using the same method as in Example 1, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum. S1-T1 Next, τ was measured under 360 nm excitation light using a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12). P The time to response (RT) was measured to be 1.4 seconds.

[0172] [ka]

[0173] Next, the Φ of dye 6 in benzene was determined by the method described in Non-Patent Document (I). ISC (RT) was measured and was 84%, which was almost 100-Φ F The determined Φ was equivalent to the (RT)% value. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain kp The calculated value is 8.0 × 10 -3 s -1 Next, the τ of sample 8 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of k was created. This graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was Q The exponential fitting line in the low temperature region is k NR As derived from k NR (RT) and k Q (RT) was separated and found to be 0.57 s -1 and 0.136s -1 It was.

[0174] The optimized structure of dye 6 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.166. Next, the optimized structure of T1 of dye 6 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation yielded 3.5 × 10 -3 s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 2.20 × 10 -10 D 2 and 1.89 x 10 -1 cm -2 It was.

[0175] (Comparative Example 6) 99.7 wt% β-estradiol and 0.3 wt% Dye 7 (manufactured by Aldrich) represented by the following structure 12 were weighed into a glass bottle and heated to 220°C to dissolve Dye 7 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to prepare Sample 9, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of Sample 9 during irradiation with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 14%. P (RT) was measured in the atmosphere and found to be 4.1%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P (RT) was used to determine the value as 10%. In addition, the emission spectrum during irradiation with excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured, and λ P The peak energy of the emission spectrum during irradiation with excitation light was 548 nm. From the difference between the peak energy of the emission spectrum on the short wavelength side and the peak energy of the room temperature phosphorescence spectrum, E S1-T1 Next, τ was measured under 360 nm excitation light using a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12). P The time to response (RT) was measured to be 4.1 seconds.

[0176] [ka]

[0177] Next, the Φ of dye 7 in benzene was determined by the method described in Non-Patent Document (I). ISC (RT) was measured and was 90%, which was almost 100-Φ F The determined Φ was equivalent to the (RT)% value. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k pThe calculated result is 9.7 × 10 -3 s -1 Next, the τ of sample 9 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of k was created. This graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was Q The exponential fitting line in the low temperature region is k NR As derived from k NR (RT) and k Q (RT) was separated and was 0.20 s -1 and 0.003s -1 It was.

[0178] The optimized structure of dye 7 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.166. Next, the optimized structure of T1 of dye 7 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation yielded 3.5 × 10 -3 s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 2.20 × 10 -10 D 2 and 1.89 x 10 -1 cm -2 It was.

[0179] (Comparative Example 7) 99.7 wt% β-estradiol and 0.3 wt% dye 3 were weighed into a glass bottle and heated to 220°C to dissolve dye 3 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to prepare sample 10, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 22%. P (RT) was measured in the atmosphere and was 4%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P (RT) was used to determine the value as 18%. In addition, the emission spectrum during irradiation with excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured, and λ P The peak energy was 556 nm. From the difference between the peak energy of the short wavelength side of the emission spectrum during irradiation with excitation light and the peak energy of the room temperature phosphorescence spectrum, E S1-T1 Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ P The time to response (RT) was measured to be 0.52 seconds.

[0180] Next, the Φ of dye 3 in benzene was obtained by the method described in Non-Patent Document (I). ISC (RT) was measured and was 95%, which was almost 100-Φ F The determined Φ was roughly equivalent to the (RT)% value. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.10s -1 Next, the τ of sample 10 P was measured from 77K to 400K, and k P Using k NR +k QA graph of the temperature dependence of k was created. This graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was Q The exponential fitting line in the low temperature region is k NR As derived from k NR (RT) and k Q (RT) was separated and found to be 1.6 s -1 and 0.31s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F (RT) was measured to be 3.4ns. F k F =Φ F (RT) / τ F (RT) was determined to be 5.3 × 10 7 s -1 It was.

[0181] Using Gaussian09, the optimized structure of dye 3 at S1 was determined by DFT using B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.020. Next, the optimized structure of T1 of dye 3 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.19s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 3.57 × 10 -7 D 2 and 5.56 x 10 -1 cm -2 It was.

[0182] (Comparative Example 8) Dye 8, represented by the following structure 13, was synthesized as follows.

[0183] [ka]

[0184] Dye 3 was synthesized in the same manner as in Comparative Example 3. 150 mg of this white powder, 100 mg of 10% palladium carbon, and 30 ml of heavy water were placed in a 50 ml Teflon (registered trademark) container-mounted autoclave and reacted for 12 hours at 250°C and 4 to 5 MPa. After cooling the reaction solution to room temperature, it was extracted with ethyl acetate and water. The organic layer was dried using sodium sulfate and then purified using column chromatography (silica gel: ethyl acetate / hexane; 2 / 98 vol) to obtain dye 8 powder (122 mg). The deuteration rate was confirmed using 1H NMR and was found to be 89.1%.

[0185] 99.7 wt% β-estradiol and 0.3 wt% dye 8 were weighed into a glass bottle and heated to 220°C to dissolve dye 8 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to prepare sample 11, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 11 during irradiation of 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 29%. P (RT) was measured in the atmosphere and found to be 11%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P (RT) was used to determine the value as 18%. In addition, the emission spectrum during irradiation with excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured, and λ PThe peak energy was 556 nm. From the difference between the peak energy of the short wavelength side of the emission spectrum during irradiation with excitation light and the peak energy of the room temperature phosphorescence spectrum, E S1-T1 Next, τ was measured under 360 nm excitation light using a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12). P The time to response (RT) was measured to be 1.6 seconds.

[0186] Next, the Φ of dye 8 in benzene was determined by the method described in Non-Patent Document (I). ISC (RT) was measured and was 97%, which was almost 100-Φ F The values were close to the (RT)% values. Decided Φ P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.10s -1 Next, the τ of sample 11 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of k was created. This graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was Q The exponential fitting line in the low temperature region is k NR As derived from k NR (RT) and k Q (RT) was separated and found to be 0.52 s -1 and 0.077s -1 Next, we measured the τ of sample 11 using a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau). F (RT) was measured to be 3.3ns. F k F =Φ F (RT) / τ F (RT) was determined to be 5.5 × 10 7 s -1 It was.

[0187] The optimized structure of dye 8 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.020. Next, the optimized structure of T1 of dye 8 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.19s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 3.57 × 10 -7 D 2 and 5.56 x 10 -1 cm -2 It was.

[0188] (Comparative Example 9) Dye 9, represented by the following structure 14, was synthesized by the following method.

[0189] [ka]

[0190] 3-Bromophenanthrene (100 mg), diphenylamine (65 mg), tris(dibenzylideneacetone)dipalladium (3.57 mg), sodium t-butoxide (38 mg), tri-t-butylphosphine (1.58 mg), and anhydrous toluene (2 ml) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was removed, dehydrated with sodium sulfate, and purified by column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to yield a white powder (108 mg, 81%). 1 H NMR (DMSO-D6, 500 MHz): δ 8.30-8.27 (m, 2 H), 7.94 (d, 1 H, J = 10 Hz), 7.90 (d, 1 H, J = 10 Hz), 7.75 (q, 1 H, J = 10 Hz), 7.60-7.52 (m, 2 H), 7.34-7.29 (m, 5 H), 7.11-7.06 (m, 6 H) ppm; 13 C NMR (DMSO-D6, 125 MHz): δ 147.29, 146.10, 131.88, 130.77, 129.90, 129.64, 128.88, 128.51, 127.61, 126.92, 126.65, 126.38, 125.34, 123.97, 123.88, 123.23, 122.44, 116.00 ppm;HRMS (m / z): [M] + calcd. for C 26 H 19 N, 345.1517; found, 345.15272; analysis (calcd., found for C 26 H 19 N): C (90 .40, 90.63), H (5.54, 5.48), N (4.05, 3.96). 80 mg of this white powder, 100 mg of 10% palladium-carbon, and 30 ml of heavy water were placed in a 50 ml Teflon (registered trademark) container-mounted autoclave and reacted for 12 hours at 250°C and 4-5 MPa. After cooling the reaction solution to room temperature, it was extracted with ethyl acetate and water. The organic layer was dried over sodium sulfate and then purified using column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to obtain dye 9 powder (68 mg). The deuteration rate was confirmed by 1H NMR and was found to be 99.9%.

[0191] 99.7 wt% β-estradiol and 0.3 wt% dye 9 were weighed into a glass bottle and heated to 220°C to dissolve dye 9 in β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 12, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 12 during irradiation with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 28%. P (RT) was measured in the atmosphere and was 9.1%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P (RT) was used to determine the value as 19%. In addition, the emission spectrum during irradiation with excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured, and λ P The peak energy was 510 nm. From the difference between the peak energy of the short wavelength side of the emission spectrum during irradiation with excitation light and the peak energy of the room temperature phosphorescence spectrum, E S1-T1 Next, τ was measured under 360 nm excitation light using a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12). P The time to response (RT) was measured to be 3.2 seconds.

[0192] Next, the Φ of dye 9 in benzene was determined by the method described in Non-Patent Document (I). ISC (RT) was measured and found to be 62%, which is almost 100-Φ F The value was close to the (RT)% value. Decided Φ P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.032s -1 Next, the τ of sample 12 P was measured from 77K to 400K, and k P Using k NR +kQ A graph of the temperature dependence of k was created. This graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was Q The exponential fitting line in the low temperature region is k NR As derived from k NR (RT) and k Q (RT) was separated and found to be 0.17 s -1 and 0.10s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F (RT) was measured to be 9.9ns. F k F =Φ F (RT) / τ F (RT) was determined to be 2.0 × 10 7 s -1 It was.

[0193] The optimized structure of dye 9 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.064. Next, the optimized structure of T1 of dye 9 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.17s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 3.78 × 10 -7 D 2 and 1.92 x 10 -1 cm -2 It was.

[0194] (Comparative Example 10) 99 mg of polymethyl methacrylate (PMMA) represented by the following structure 15 and 1 mg of dye 10 represented by the following structure 16 were dissolved in 1 ml of chloroform, and the solution was dropped onto a quartz substrate. A thin film of 1 wt% of dye 10 dispersed in PMMA on the quartz substrate was fabricated as sample 13 by spin coating. The thin film was placed in a cryostat (Oxford Instruments, Optistat-DNV), and the τ of sample 13 under vacuum was measured using a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau). P The RT was measured and found to be 3 milliseconds. PL The RT was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and was found to be very small. ISC Since (RT) is reported as 100% in non-patent documents (II) and (III), Φ P (RT)≒0, Φ ISC (RT), τ P (RT) to obtain k from equations (I) and (II). NR (RT) and k Q The sum of (RT) is 3.3 x 10 2 s -1 This value was equivalent to that in Non-Patent Documents (II) and (III). In Non-Patent Document (II), k NR (RT) and k Q The values of (RT) are approximately 2.0 × 10 2 s -1 and 1.3 x 10 2 s -1 It has been decided that:

[0195] [ka]

[0196] [ka]

[0197] Non-patent document (II): K. Horie, I. Mita, Chem. Phys. Lett. 1982, 93, 61. Non-patent document (III): K. Horie, K. Morishita, I. Mita, Macromolecules 1984, 17, 1746.

[0198] The optimized structure of dye 10 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculation yielded 6.6 × 10 -4 Next, the optimized structure of T1 of dye 3 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 27.1 seconds. -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 2.37 × 10 -6 D 2 and 1.03 × 10 3 cm -2 It was.

[0199] (Comparative Example 11) Bis[2-(diphenylphosphino)phenyl]etheroxide (DPEPO) represented by the following structure 17 and dye 11 represented by the following structure 18 were co-evaporated on a quartz substrate at a ratio of 94:6 wt% to form a film, which was used as sample 14. The Φ of sample 14 under a nitrogen atmosphere during irradiation with 360 nm excitation light was PLThe RT was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 38%. Next, the luminescence lifetime of sample 14 was measured under vacuum using a compact fluorescence lifetime spectrometer (Hamamatsu Photonics, Quantaurus-Tau), and a millisecond decay component of 8.3 ns was observed. The decay of the short-lived component and the decay of the long-lived component are used to calculate the luminescence quantum yield (Φ PF (RT)) and the emission yield of the delayed component (Φ DF (RT)) were 19% and 19%, respectively. The phosphorescence spectrum observed immediately after the irradiation of the excitation light at 77 K for sample 14 was measured, and λ P The peak energy of the phosphorescence spectrum at 77 K was 492 nm. S1-T1 was determined to be 0.05-0.12 eV. F is τ F (RT)=8.3ns F =Φ F (RT) / τ F Substituting (RT) gives 2.3 × 10 7 s -1 It was decided that:

[0200] The optimized structure of dye 11 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.067.

[0201] [ka]

[0202] [ka]

[0203] The photophysical factors of Examples 2 and 3 and Comparative Examples 4 to 11 are summarized in Table 2.

[0204] [Table 2]

[0205] Figure 9 shows (Σ n P n ) 2 and k P Since a good correlation is confirmed, the preferred k P The range of (Σ n P n ) 2 It will be clear that it is appropriate to specify it using the above.

[0206] (Φ ISC (Comparison of the size of RT) In Examples 2 and 3, Φ ISC (RT) is large. f S1-S0 is k F is proportional to f S1-S0 When becomes large, energy is released as fluorescence before going to the triplet state, and Φ ISC In fact, in Comparative Example 4, f S1-S0 is large, and the actual experimental value k F also becomes larger, and as a result, Φ F (RT) is large, and as a result, Φ ISC (RT) is small. On the other hand, in Examples 2 and 3, f S1-S0 is small, so k F is also smaller, which results in Φ F (RT) is small, so Φ ISC (RT) is large. From the above, f S1-S0 In Examples 2 and 3, a large Φ was obtained by molecular design to reduce ISC It is understood that (RT) is obtained.

[0207] (Comparison with and without antenna unit) Examples 2 and 3 have the same τ as Comparative Examples 5 and 6. P (RT) while Φ PIn both Examples 2 and 3 and Comparative Examples 5 and 6, Φ ISC (RT) is large and τ P (RT) is also equivalent to a few seconds. Based on the above formulas (I) and (II), Φ P The difference between (RT) is k P In Examples 2 and 3, the antenna unit has an effect, which can be explained by the difference in Σ n P n becomes larger, and the experimental value of k P becomes larger, and as a result, Φ P On the other hand, in Comparative Examples 5 and 6, there is no antenna unit, so Σ n P n becomes smaller, and the experimental value of k P becomes smaller, and as a result, Φ P In Examples 2 and 3 and Comparative Examples 5 and 6, the SOC T1-S0 2 Since are of the same order, k NR The experiment for (RT) is also equivalent. From the above, by introducing the antenna unit, k NR Without increasing (RT), k P As a result of the improved P (RT) while maintaining a large Φ P It is understood that (RT) is obtained.

[0208] (Comparing the length of the antenna unit) Examples 2 and 3 have τ equivalent to Comparative Examples 7 to 9. P (RT) is shown, but in Examples 2 and 3, the antenna length is longer than in Comparative Examples 7 to 9, so Φ P In Examples 2 and 3, as in Comparative Examples 7 to 9, the large Φ ISC To show (RT), Φ ISC The difference between (RT) is Φ P In Examples 2 and 3, the antenna unit is longer than in Comparative Examples 7 to 9, which contributes little to the difference in Σ n P n becomes larger, and the experimental value of k P becomes larger, and based on formula (I), Φ PIn this case, the SOC T1-S0 2 Since are of the same order, k NR The (RT) experiment is equivalent. From the above, by expanding the antenna of the antenna unit, k NR Without increasing (RT), k P As a result of the improved P Larger Φ while maintaining (RT) P It is understood that (RT) is obtained.

[0209] (k NR (Compare RT) When Examples 2 and 3 are compared with Comparative Example 10, both have Φ ISC (RT), Σ n P n , and k P is large, but the SOC of Comparative Example 10 T1-S0 2 is large enough for Examples 2 and 3, so k NR (RT) is large. In Comparative Example 10, k P For k NR (RT) is large enough, so k P << <k NR (RT) for Φ P Not only does (RT) become smaller, but τ P (RT) also becomes shorter to the millisecond range, and the phosphorescent function does not appear. S1-S0 Make smaller and larger Φ ISC (RT) and then use a larger k P For large Σ n P n In the molecule where k P >k NR (RT) is insufficient to obtain highly efficient room-temperature phosphorescence with long-lasting properties, and a small k NR (RT) for SOC T1-S0 2 It will be understood that a molecule that inhibits this is required.

[0210] (E S1-T1 (Compare the differences between When Examples 2 and 3 are compared with Comparative Example 11, in both cases, S1-S0 Since k is small F is small and Φ ISC Although (RT) is large, no long-lasting luminescence is obtained in Comparative Example 11. S1-T1 In this case, after T1 is formed, it returns to S1 at high speed and the energy of T1 is rapidly radiated as delayed fluorescence, so the phosphorescent function cannot be obtained. On the other hand, in Examples 2 and 3, E S1-T1 Since it is large enough that the energy is hardly returned to S1 at room temperature after T1 formation, k P >k NR (RT) and SOC T1-S0 2 is small, so k NR (RT) becomes small enough that highly efficient room temperature phosphorescence is emitted as a phosphorescent function. S1-T1 It will be appreciated that molecules with small sizes are not suitable as highly efficient light-sustaining emissive molecules.

[0211] "Manufacturing example C" Example 4 Φ of Sample 1 in Example 1 during irradiation with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 60%. P (RT) was measured in air and was found to be 30%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ emitted in the atmosphere after the irradiation of the 360 nm wavelength excitation light of sample 1 was stopped. P The time to response (RT) was measured to be 1.0 seconds.

[0212] Example 5 A sample was prepared in the same manner as in Example 1, except that β-estradiol was changed to 99 wt % and dye 1 was changed to 1 wt %, and this was designated as Sample 15. PLThe absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 63%. P (RT) was measured in air and was found to be 38%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ emitted in the atmosphere after the irradiation of the 360 nm wavelength excitation light of the sample 15 was stopped. P The time to response (RT) was measured to be 0.72 seconds.

[0213] Example 6 A sample was prepared in the same manner as in Example 1, except that β-estradiol was changed to 99.9 wt% and dye 1 was changed to 0.1 wt%, and this was designated as Sample 16. PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and was found to be 71%. P (RT) was measured in air and was 46%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ emitted in the atmosphere after the irradiation of the 360 nm wavelength excitation light of the sample 16 was stopped. P The time to response (RT) was measured to be 0.61 seconds.

[0214] (Comparative Example 12) Φ during irradiation of 360 nm excitation light on powder of dye 1 (sample 17) PL (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) to obtain Φ P (RT) Measurements in air yielded 0%.

[0215] The Φ of Examples 2, 4 to 6 and Comparative Example 12 P (RT) and τ P(RT) data are summarized in Table 3. Comparing Examples 2 and 4 to 6 with Comparative Example 12, it can be seen that the concentration of the molecules according to the present invention dispersed in the solid host is preferably 30% or less, more preferably 10% or less.

[0216] [Table 3]

[0217] "Manufacturing example D" Example 7 Sample 18 was prepared in the same manner as in Example 2, except that β-estradiol was replaced with (S)H8-BINAP (manufactured by Aldrich) represented by the following structure 19. Φ during irradiation of sample 18 with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and was found to be 50%. P When measured in the air, it was 19%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ emitted in the atmosphere after the irradiation of the 360 nm wavelength excitation light of the sample 18 was stopped. P The time to response (RT) was measured to be 0.67 seconds.

[0218] [ka]

[0219] The above Φ of Examples 2 and 7 P (RT) and τ P The (RT) data are summarized in Table 4. Comparing Examples 2 and 7, it can be seen that the molecules of the present invention exhibit efficient and long-lived room temperature phosphorescence in a variety of solid hosts.

[0220] [Table 4]

[0221] "Manufacturing Example E" Example E1: Data for Compound 6 Compound 11, represented by the following structure, was synthesized by the following method. The evaluation results are shown in Table 5.

[0222] [ka]

[0223] 1-Bromonaphthalene (162 mg), di(9H-fluoren-2-yl)amine (123 mg), tris(dibenzylideneacetone)dipalladium (4.8 mg), sodium t-butoxide (34 mg), tri-t-butylphosphine (2.8 mg), and anhydrous toluene (2.5 ml) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and purified water, and the organic layer was removed, dehydrated over sodium sulfate, and purified by column chromatography (silica gel: dichloromethane / hexane; 20 / 80 vol) to yield a yellow powder (145 mg, 0.25 mmol, 73%). 1 H NMR (CDCl3, 500 MHz,):δ=8.63 (d, J=10 Hz, 2H), 8.50-8.57 (m, 2H), 8.36 (s, 1H), 8.27 (d, J=10 Hz, 1H), 7.74 (t, J=10 Hz, 4H), 7.58-7.66 (m, 3H), 7.44-7.54 (m, 4H), 7.42 (s, 2H), 7.38 (t, J=7.5 Hz, 2H), 7.29 (t, J=10 Hz, 4H), 3.86 (s, 4H); 13C NMR (CDCl3, 126 MHz,): δ=144.81, 143.17, 141.47, 130.08, 129.82, 129.37, 129.07, 127.27, 127.09, 126.84, 126.44, 126.11, 124.98, 124.46, 123.75, 123.63, 123.42, 123.26, 122.90, 121.53, 120.63, 119.43, 36.94;

[0224] 99.7 wt% β-estradiol and 0.3 wt% compound 6 were weighed into a glass bottle and heated to 220°C to dissolve compound 6 in the β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 18, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 18 during irradiation with 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 46%. P (RT) was measured in the atmosphere and found to be 21%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ under 360 nm excitation light for the sample. P The time to response (RT) was measured to be 0.53 seconds.

[0225] For sample 18, the emission spectrum during irradiation with 360 nm excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G). λ P Furthermore, using the same method as in Example 2, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum. S1-T1was determined to be 0.54 eV.

[0226] Next, the Φ of compound 6 in benzene was obtained by the method described in Non-Patent Document (I). ISC (RT) was measured and found to be 64%, which is almost 100-Φ F The determined value of Φ was equivalent to that of %. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.52 seconds. -1 Next, the τ of sample 18 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of was created. The graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is k NR As a result of the room temperature k NR (RT) and k Q (RT) was separated and found to be 0.39 s -1 and 1.0s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F (RT) was measured to be 3.7 ns. F k F =Φ F (RT) / τ F (RT) was determined to be 6.8 × 10 7 s -1 It was.

[0227] Using Gaussian09, the optimized structure of dye 4 at S1 was determined by DFT using B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0The calculated value was 0.063. Next, the optimized structure of T1 of compound 6 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 1.24s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 1.39 × 10 -6 D 2 and 3.68 x 10 -1 cm -2 It was.

[0228] (Example E2: Data for Compound 8) Compound 8 represented by the following structure was synthesized by the following method. The evaluation results are shown in Table 5.

[0229] [ka]

[0230] Coronene (500 mg) and acetic anhydride (10 mL) were stirred at 0°C for 15 minutes. Fuming nitric acid (126 μL) was added dropwise to the solution, which was then stirred at 0°C for 3 hours. Concentrated sulfuric acid (196 μL) was slowly added dropwise to the solution, maintaining the temperature at 0°C. The reaction solution was gradually heated to room temperature and stirred overnight at 0°C, yielding a yellow precipitate. The precipitate was washed with water, isopropanol, and diethyl ether to obtain 1-nitrocoronene, although some impurities were present. 1-nitrocoronene (300 mg), lead chloride (784 mg), and concentrated hydrochloric acid (3 mL) were stirred in ethanol (10 mL) at 80°C for 6 hours. During the reaction, aqueous sodium hydroxide solution was added dropwise to maintain the pH of the reaction solution at 7. The reaction solution was separated using ethyl acetate and saturated brine, and the organic layer was dehydrated using sodium sulfate and then purified using column chromatography (silica gel: ethyl acetate / hexane; 20 / 80 vol) to obtain a yellow powder (170 mg, 0.54 mmol, 62%). 1 H NMR (DMSO-D6, 500 MHz): δ 9.20 (d, 1H, J = 10 Hz), 8.99-8.80 (m, 8H), 8.71 (d, 1H, J = 10 Hz), 8.11 (s, 1H), 6.70 (s, 2H) ppm. 13 C NMR (CDCl3, 125 MHz): δ 151.21, 148.32, 132.87, 131.96, 131.12, 130.58, 129.75, 128.37, 126.46, 124.27, 122.34, 121.14, 120.84 ppm. HRMS-ESI (m / z): [M+H] + calcd. for C 24 H 14 N, 316.1126; found 316.1149.

[0231] 1-Aminocoronene (80 mg), 2-bromo-9H-fluorene (130 mg), tris(dibenzylideneacetone)dipalladium (2.3 mg), sodium t-butoxide (24 mg), tri-t-butylphosphine (2.0 mg), and anhydrous toluene (3 mL) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was removed, dehydrated over sodium sulfate, and purified by column chromatography (silica gel: dichloromethane / hexane; 5 / 95 vol) to yield a yellow powder (108 mg, 0.17 mmol, 66%). 1 H NMR (CDCl3, 500 MHz): δ 9.08 (d, J = 10 Hz, 1H), 8.93-8.85 (m, 7H), 8.81-8.76 (m, 3H), 7.70 (t, J = 10 Hz, 4H), 7.46 (d, J = 10 Hz, 2H), 7.41 (s, 2H), 7.36-7.32 (m, 4H), 7.24 (t, J = 10 Hz, 2H), 3.75 (s, 4H) ppm; 13C NMR (CDCl3, 125 MHz): 148.80, 144.95, 143.13, 142.84, 141.74, 136.19, 129.70, 128.93, 128.68, 126.98, 126.89, 126.82, 126.70, HRMS (m / z): [M] + calcd. for C 50 H 29 N, 643.23000; found 643.23420 (Figure S3); analysis (calcd., found for C 50 H 29N): C (93.28, 93.35), H (4.54, 4.60), N (2.18, 2.37).

[0232] 99.7 wt% β-estradiol and 0.3 wt% compound 8 were weighed into a glass bottle and heated to 220°C to dissolve compound 8 in the β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to produce sample 19, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 19 during irradiation of 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 39%. P (RT) was measured in the atmosphere and found to be 19%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ under 360 nm excitation light for the sample 19. P The time to response (RT) was measured to be 1.8 seconds.

[0233] For sample 19, the emission spectrum during irradiation with 360 nm excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G). λ P Furthermore, using the same method as in Example 2, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum. S1-T1 was determined to be 0.50 eV.

[0234] Next, the Φ of compound 8 in benzene was obtained by the method described in Non-Patent Document (I). ISC (RT) was measured and was 84%, which was almost 100-Φ F The determined value of Φ was equivalent to that of %. P(RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.13 seconds. -1 Next, the τ of sample 19 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of was created. The graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is k NR As a result of the room temperature k NR (RT) and k Q (RT) was separated and found to be 0.27 s -1 and 0.11s -1 Next, we measured the τ of sample 19 using a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau). F (RT) was measured to be 7.1 ns. F k F =Φ F (RT) / τ F (RT) was determined to be 2.8 × 10 7 s -1 It was.

[0235] The optimized structure of compound 8 at S1 was determined by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.057. Next, the optimized structure of T1 of compound 8 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.47s -1 Furthermore, using the optimized structure, (Σ n Pn ) 2 and SOC T1-S0 2 were calculated to be 1.06 × 10 -6 D 2 and 4.12 x 10 -1 cm -2 It was.

[0236] Example E3: Data for Compound 9 Compound 9, represented by the following structure, was synthesized with reference to the following literature: Indranil Bhattacharjee, Shuzo Hirata, Highly Efficient Persistent Room-Temperature Phosphorescence from Heavy Atom-Free Molecules Triggered by Hidden Long Phosphorescent Antenna, Advanced Materials, 2020, 32, 2001348. The evaluation results are shown in Table 5.

[0237] [ka]

[0238] 99.7 wt% β-estradiol and 0.3 wt% compound 9 were weighed into a glass bottle and heated to 220°C to dissolve compound 9 in the β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to prepare sample 20, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 35%. P (RT) was measured in the atmosphere and was found to be 12%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ PNext, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ under 360 nm excitation light of the sample 20. P The time to response (RT) was measured to be 1.0 seconds.

[0239] For sample 20, the emission spectrum during irradiation with 360 nm excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G). P Furthermore, using the same method as in Example 2, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum. S1-T1 was determined to be 0.64 eV.

[0240] Next, the Φ of compound 9 in benzene was obtained by the method described in Non-Patent Document (I). ISC (RT) was measured and found to be 64%, which is almost 100-Φ F The determined value of Φ was equivalent to that of %. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.16s -1 Next, the τ of sample 20 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of was created. The graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is k NR As a result of the room temperature k NR (RT) and k Q (RT) was separated and found to be 0.71 s -1 and 0.12s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F(RT) was measured to be 2.1 ns. F k F =Φ F (RT) / τ F (RT) was determined to be 1.1 × 10 8 s -1 It was.

[0241] Using Gaussian09, the optimized structure of dye 4 at S1 was determined by DFT using B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.042. Next, the optimized structure of T1 of compound 9 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the ADF2018 package was used to calculate k using Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.37s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 4.97 × 10 -7 D 2 and 3.42 x 10 -1 cm -2 It was.

[0242] Example E4: Data for Compound 10 Compound 10 represented by the following structure was synthesized by the following method. The evaluation results are shown in Table 5.

[0243] [ka]

[0244] 200 mg of 1-aminocoronene (as synthesized in Example E2), 150 mg of 10% palladium-carbon, and 30 ml of heavy water were placed in a 50 ml Teflon (registered trademark) autoclave and reacted at 250°C and 4-5 MPa for 12 hours. After cooling the reaction solution to room temperature, it was extracted with ethyl acetate and water. The organic layer was dried over sodium sulfate and then purified using column chromatography (silica gel: ethyl acetate / hexane; 20 / 80 vol). 182 mg of deuterated 1-aminocoronene powder was obtained. The deuteration rate was confirmed by 1H NMR and was found to be 98%. HRMS-ESI (m / z): [M] + calcd. for C 24 D 13 N, 328.18; found, 327.13.

[0245] Deuterated 1-aminocoronene (90 mg), di(9H-fluoren-2-yl)amine (132 mg), tris(dibenzylideneacetone)dipalladium (2.5 mg), sodium t-butoxide (26 mg), tri-t-butylphosphine (2.2 mg), and anhydrous toluene (3 mL) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was removed, dehydrated over sodium sulfate, and purified by column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to yield a yellow powder (108 mg, 0.17 mmol, 59%). 1 H NMR (CDCl3, 500 MHz): δ 9.08 (d, 0.02H, J = 10 Hz), 8.93-8.85 (m, 0.14H), 8.81-8.76 (m, 0.05H), 7.70 (t, 4H, J = 10 Hz), 7.46 (d, 2H, J = 10 Hz), 7.41 (s, 2H), 7.36-7.32 (m, 4H), 7.24 (t, 2H, J = 10 Hz), 3.75 (s, 4H) PPM. 13C NMR (CDCl3,125 MHz): 148.34, 144.42, 142.73, 142.28, 141.18, 136.19, 129.70, 128.93, 127.99, 126.54, 126.13, 126.24, 126.70, 126.65, 126.39, 126.33, 126.20, 125.93, 124.99, 124.78, 123.00, 121.90, 120.73, 119.60, 119.36, 37.08 ppm; 1 H NMR Analysis revealed that the deuteration rate of the coronene skeleton was 98%.

[0246] 99.7 wt% β-estradiol and 0.3 wt% compound 10 were weighed into a glass bottle and heated to 220°C to dissolve compound 10 in the β-estradiol. The liquid was sandwiched between two quartz substrates heated to 220°C on a hot plate. After that, it was rapidly cooled to room temperature to prepare sample 21, in which the material was sandwiched between the two quartz substrates to a thickness of approximately 10 μm. Φ of sample 21 during irradiation of 360 nm excitation light PL The absolute PL quantum yield (RT) was measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G) and found to be 55%. P (RT) was measured in the atmosphere and was found to be 35%. F (RT) to Φ F (RT)=Φ PL (RT)-Φ P Next, a time-resolved two-dimensional photodetector (Hamamatsu Photonics, PMA-12) was used to measure the τ under 360 nm excitation light of the sample 21. P The time to response (RT) was measured to be 2.2 seconds.

[0247] For sample 21, the emission spectrum during irradiation with 360 nm excitation light and the phosphorescence spectrum immediately after the irradiation with excitation light were measured using an absolute PL quantum yield spectrometer (Hamamatsu Photonics, C9920-02G). PFurthermore, using the same method as in Example 2, E was calculated from the difference between the rising energy of the spectrum on the short wavelength side of the emission spectrum during irradiation with excitation light and the rising energy of the room temperature phosphorescence spectrum. S1-T1 was determined to be 0.50 eV.

[0248] Next, the Φ of compound 10 in benzene was obtained by the method described in Non-Patent Document (I). ISC (RT) was measured and was 88%, which was almost 100-Φ F The determined value of Φ was equivalent to that of %. P (RT), Φ ISC (RT), τ P (RT) into the above formula (I) to obtain k p The calculated result was 0.20s -1 Next, the τ of sample 21 P was measured from 77K to 400K, and k P Using k NR +k Q A graph of the temperature dependence of was created. The graph was fitted with the sum of two exponential functions, and the exponential fitting in the high temperature range was k Q The exponential fitting line in the low temperature region is k NR As a result of the room temperature k NR (RT) and k Q (RT) was separated and found to be 0.16 s -1 and 0.10s -1 Next, a compact fluorescence lifetime analyzer (Hamamatsu Photonics, Quantaurus-Tau) was used to measure the τ F (RT) was measured to be 7.1 ns. F k F =Φ F (RT) / τ F (RT) was determined to be 2.8 × 10 7 s -1 It was.

[0249] Using Gaussian09, the optimized structure of dye 4 at S1 was determined by DFT using B3LYP as the functional and 6-31G(d) as the basis set. This optimized structure was then used to calculate the f S1-S0 The calculated value was 0.057. Next, the optimized structure of T1 of compound 10 was calculated by DFT using Gaussian09 with B3LYP as the functional and 6-31G(d) as the basis set. Next, using this optimized structure, the k was calculated using the ADF2018 package with Hybrid-PBE0 as the functional and TZP as the basis set. P The calculation was 0.47s -1 Furthermore, using the optimized structure, (Σ n P n ) 2 and SOC T1-S0 2 were calculated to be 1.06 × 10 -6 D 2 and 4.12 x 10 -1 cm -2 It was.

[0250] Example E5: Data for Compound 11 Compound 11 represented by the following structure 1 was synthesized by the following method: That is, a compound in a non-deuterated state was obtained in the above Production Example A.

[0251] [ka]

[0252] 1-Bromonaphthalene (200 mg), di(9H-fluoren-2-yl)amine (333 mg), tris(dibenzylideneacetone)dipalladium (8.8 mg), sodium t-butoxide (92 mg), tri-t-butylphosphine (3.88 mg), and anhydrous toluene (3 mL) were reacted under a nitrogen atmosphere at 110°C overnight with stirring. The reaction solution was extracted with ethyl acetate and saturated aqueous sodium hydroxide, and the organic layer was removed, dehydrated over sodium sulfate, and purified by column chromatography (silica gel: ethyl acetate / hexane; 3 / 97 vol) to yield a yellow powder (328 mg, 0.70 mmol, 72%). 1 H NMR (DMSO-D6, 500 MHz): δ 8.03 (d, 1 H, J = 10 Hz), 7.96 (d, 1 H, J = 10 Hz), 7.92 (d, 1 H, J = 10 Hz), 7.76-7.73 (m, 4 H), 7.59 (t, 1 H, J = 10 Hz), 7.53-7.48 (m, 3 H), 7.42 (t, 3 H, J = 10 Hz), 7.32 (t, 2 H, J = 10 Hz), 7.22 (t, 2 H, J = 10 Hz), 7.14 (s, 2 H), 7.03 (d, 1 H, J = 10 Hz), 3.78 (s, 4H) ppm; 13 C NMR (CDCl3, 125 MHz): δ 148.20, 144.76, 143.11, 141.76, 135.94, 135.48, 131.32, 128.54, 127.20, 126.87, 126.54, 126.51, 126.37, 126.30, 125.88, 124.99, 124.58, 121.38, 120.48, 119.31, 119.06, 37.06 ppm; HRMS (m / z): [M] + calcd. for C 35 H 25 N, 471.1987; found, 471.19884; analysis (calcd., found for C 35 H 25N): C (91.69, 91.82), H (5.34, 5.26), N (2.97, 2.58).

[0253] Experimental and calculated values were determined in the same manner as in Example E1 above, and the results are shown in Table 5.

[0254] (Consideration of the value of equation (11)) The following values were calculated using the compounds 6, 8, and 11 synthesized above and dye 10. Compound 12 having the following structure was used as a reference substance. The results are shown in Table 6. The Knr(RT) values shown in the table are values measured in the above test examples. The calculation method using formula (11) was based on Non-Patent Document IV: S. Hirata, I. Bhattacharjee, J. Phys. Chem. A 2021, 125, 885-894.

[0255] [ka]

[0256] Example E1 The value of formula (11) of compound 6 was calculated using the method described in Non-Patent Document IV to be 0.86 × 10 -4 The value of formula (11) for compound 12, the reference substance, was 0.47 × 10 -4 This was 1.38 times higher than the previous study.

[0257] Example E2 The value of formula (11) of compound 8 was calculated using the method described in Non-Patent Document IV to be 1.2 × 10 -4 The value of formula (11) for compound 12, the reference substance, was 0.47 × 10 -4 This was 2.55 times higher than the previous study.

[0258] Example E5 The value of formula (11) of compound 11 was calculated using the method described in Non-Patent Document IV to be 5.9 × 10 -4 The value of formula (11) for compound 12, the reference substance, was 0.47 × 10-4 This was 12.6 times higher than the previous study.

[0259] (Comparative Example 10) The value of formula (11) of dye 10 was calculated using the method described in Non-Patent Document IV to be 1.7 × 10 -2 The value of formula (11) for compound 12, the reference substance, was 0.47 × 10 -4 This was 362 times higher than that of

[0260] (Reference example) The SOC for the above-mentioned compounds 6, 8, and 11 and dye 10 is as follows: T1-S0 2 The values were compared against the reference material. SOC of compound 6 T1-S0 2 is 3.68 × 10 as in Example E1 -1 (cm -2 ) and the SOC of the reference substance, compound 12. T1-S0 2 was calculated using the same method, and the result was 3.4 × 10 -7 (cm -2 ) Thus, the SOC of compound 6 T1-S0 2 The value was 1.08 million times higher than that of compound 12. SOC of compound 8 T1-S0 2 is 4.12 × 10 as in Example E2 -1 (cm -2 ) Thus, the SOC of compound 8 T1-S0 2 The value was 1.21 million times that of compound 12. SOC of compound 11 T1-S0 2 is 6.29 × 10 as in Example E3 -1 (cm -2 ) Thus, the SOC of compound 11 T1-S0 2 The value was 1.85 million times higher than that of compound 12. SOC of dye 10 T1-S0 2 is 1.03 x 10 as in Comparative Example 10. 3 (cm-2 ) Thus, the SOC of dye 10 T1-S0 2 The value was 3 billion times higher than that of compound 12.

[0261] By using the value of equation (11), k nr The accuracy of the estimation of (RT) is greatly improved. For example, as shown in Table 6, the k nr The RT values are 3.25, 2.25, 15.0, and 1670 times those of the reference compound 12, respectively. These values are close to the relative values of the reference compound (11) estimated in Examples A to D, and show good correlation. T1-S0 2 In the comparative examples A to D, the SOC of compounds 6, 8, 11, and dye 10 was estimated. T1-S0 2 are 1.08 million, 1.21 million, 1.85 million, and 3 billion times that of the reference compound 12, respectively. Therefore, there are compounds for which a good correlation cannot be obtained. Also, in the estimation of equation (11), smaller k nr The predicted level of the skeleton of (RT) is greatly improved. nr The value of (RT) is 4.6 to 6.7 times that of compounds 6 and 8, but the estimate by equation (11) is also 4.9 to 6.9 times. nr The decrease in RT results in compounds 6 and 8 with a larger Φ than compound 11. p On the other hand, the SOC of compound 11 was T1-S0 2 is 1.1 to 1.7 times that of compounds 6 and 8. Therefore, the method using equation (11) is suitable for achieving a small k nr It will be understood that this is a method for accurately depicting (RT).

[0262] [Table 5]

[0263] [Table 6]

Claims

1. In the density functional theory, the lowest excited triplet state T is calculated using the functional B3LYP and the basis set 6-31G(d). １ Optimizing the molecular structure of lowest excited triplet state T １ In the optimized structure of ｎ and the ground state S ０ The transition dipole moment (μ Ｓｎ－Ｓ０ ), S ｎ and T １ Spin-orbit interaction (SOC) between Ｓｎ－Ｔ１ ), and S ｎ and T １ The energy difference (E Ｓｎ－Ｔ１ ) in the relationship P ｎ = μ Ｓｎ－Ｓ０ SOC Ｓｎ－Ｔ１ / E Ｓｎ－Ｔ１ When we define The calculation was performed using the functional PBE0 and the basis set TZP in the density functional theory (Σ ｎ P ｎ ) ２ The range is 4.00 x 10 －７ D ２ That's all, T calculated using the functional PBE0 and basis set TZP in the density functional theory １ and S ０ Spin-orbit interaction (SOC Ｔ１－Ｓ０ ) squared is 1 x 10 １ cm －２ is as follows: The ground state S optimized using the functional B3LYP and the basis set 6-31G(d) in the density functional theory ０ Optimized structure and lowest singlet excited state S １ In any of the optimized structures, S calculated using the functional PBE0 and the basis set TZP in the density functional theory １ and S ０ The oscillator strength (f Ｓ１－Ｓ０ ) is a molecule in which The molecule comprises a light-emitting material, which is a compound represented by the following general formula (IV): The concentration of the luminescent material is 0.001% by mass to 30% by mass. 【Chemical 1】 (In general formula (IV), R １ and R ２ are each independently a hydrogen atom or a monovalent group, R １’ and R ２’ are each independently a hydrogen atom or a monovalent group, R is a hydrogen atom or any monovalent group, R １ , R ２ , R １’ , R ２’ and R may be the same or different from each other, R ｃｅｎｔｒｅ is a group representing a center unit, and is a substituted or unsubstituted p-terphenyl group, a substituted or unsubstituted p-quaterphenyl group, a substituted or unsubstituted group having a fused benzene ring having 12 to 80 carbon atoms, or a substituted or unsubstituted group having a fused heterocyclic ring having 12 to 80 carbon atoms.

2. In the density functional theory, the lowest excited triplet state T is calculated using the functional B3LYP and the basis set 6-31G(d). １ and calculating formula (11) using the optimized structure in a density functional theory with the functional PBE0 and the basis function TZP, the value of the compound (12) is 100 times or less than the value of the compound (12). [Equation 1] (In formula (11), Q ｐ is T １ The molecular configuration in the p-th vibration mode in the optimized structure of １ and S ０ is the Frank-Condon factor between ＳＯ is the Hamiltonian corresponding to the spin-orbit coupling.) 【number】

3. The molecule is S １ and T １ The energy difference (E Ｓ１－Ｔ１ 3. The solid light-storing material according to claim 1, wherein the charge transport potential is 0.2 eV or more.

4. The molecule has an aromatic ring or a heterocyclic ring in which a carbon atom on the ring is directly bonded to a nitrogen atom, at least one of which is an antenna unit and at least one of which is a center unit, and the T １ The energy of the antenna unit is T １ The solid state light-storage material according to claim 1 , wherein the energy is smaller than that of the solid state light-storage material according to claim 1 .

5. A display medium having a layer containing the solid light-storing material according to claim 1 .

6. Particles comprising the solid light-storage material according to any one of claims 1 to 4, and having a diameter of 10 µm or less.

7. An ink comprising the particles of claim 6.

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