Photon upconversion compositions, films, methods and compounds for converting visible light to ultraviolet light

Abstract

This photon upconversion composition including a naphthalene compound obtained by substitution with a substituent including at least one selected from a group consisting of an alkynyl group, a substituted silyl group, a benzene ring, a heterocyclic aromatic ring, a cyano group, and a halogen atom, is capable of efficiently converting excitation light into ultraviolet light at a low excitation intensity.

Description

[Technical Field]

[0001] The present invention relates to photon upconversion compositions useful as sources of ultraviolet light generation, compounds useful as acceptors for the photon upconversion compositions, and films and methods for converting visible light to ultraviolet light using the photon upconversion compositions. [Background technology]

[0002] Photon upconversion is a technology that converts low-energy light into high-energy light, and is attracting attention as an energy generation technology that can improve the efficiency of solar cells, photocatalysts, and other solar-powered devices. A known material system that exhibits photon upconversion is a photon upconversion composition that combines a donor that functions as a sensitizer and an acceptor that functions as an emitter. In this composition, when the donor is excited to an excited singlet state by irradiation with excitation light, it undergoes intersystem crossing to an excited triplet state, and the triplet energy is transferred to the acceptor. When the acceptor receives energy and reaches an excited triplet state, the triplets between the two molecules meet, causing triplet-triplet annihilation, and one of the molecules transitions to an excited singlet state with higher energy than the excited triplet state, resulting in light emission (photon upconversion emission). This composition can convert irradiated light into light with higher energy (light with a shorter wavelength) through the photon upconversion mechanism of triplet-triplet annihilation. Incidentally, possible light conversion methods using photon upconversion compositions include converting visible light to shorter-wavelength visible light and converting visible light to ultraviolet light. Of these, the method of converting visible light to ultraviolet light can be used effectively as a source of ultraviolet light in various situations where ultraviolet light is used, such as by efficiently activating photocatalysts using the resulting ultraviolet light. However, most of the photon upconversion compositions reported to date convert visible light to shorter-wavelength visible light, and there have been very few studies on compositions that convert visible light to ultraviolet light (see, for example, Non-Patent Documents 1 to 3). Furthermore, the photon upconversion compositions in these studies either require extremely high excitation light intensity or have low quantum yields, making them far from being practical. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Chem. Sci., 2017, 8, 5488-5496 [Non-patent document 2] J. Phys. Chem. Lett. 2019, 10, 5036-5040 [Non-patent document 3] ChemistryOpen 2020, 9, 14-17 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, in order to solve such problems of the conventional technology, the present inventors have conducted extensive research to provide a photon upconversion composition that can efficiently convert excitation light into ultraviolet light with a lower excitation light intensity. [Means for solving the problem]

[0005] As a result of intensive research to solve the above problems, the present inventors have found that by using a naphthalene compound substituted with a specific substituent as an acceptor, a photon upconversion composition can be realized that can efficiently convert excitation light into ultraviolet light with a lower excitation light intensity. The present invention has been proposed based on these findings, and specifically has the following configuration.

[0006] [1] A photon upconversion composition comprising a naphthalene compound substituted with a substituent containing at least one selected from the group consisting of an alkynyl group, a substituted silyl group, a benzene ring, a heteroaromatic ring, a cyano group, and a halogen atom. [2] The photon upconversion composition according to [1], wherein the naphthalene compound has a substituted silyl group. [3] The photon upconversion composition according to [1] or [2], wherein the naphthalene compound has an alkynyl group. [4] The photon upconversion composition according to any one of [1] to [3], wherein the naphthalene compound has a substituted or unsubstituted phenyl group. [5] The photon upconversion composition according to any one of [1] to [4], wherein the naphthalene compound has 2 to 4 of the substituents. [6] The photon upconversion composition according to any one of [1] to [5], wherein the naphthalene compound is a 1,4-disubstituted naphthalene. [7] The photon upconversion composition according to [1], wherein the naphthalene compound has a structure represented by the following general formula (1): [ka] [In general formula (1), R 1 , R 2 and R 3each independently represents a substituted or unsubstituted alkyl group, X represents a group consisting of one or more groups selected from the group consisting of an alkynyl group, an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom, m is an integer of 1 to 8, n is an integer of 0 to 7, and m+n is an integer of 1 to 8.] [8] The photon upconversion composition according to [7], wherein n in general formula (1) is 1 or more. [9] The photon upconversion composition according to [1], wherein the naphthalene compound has a structure represented by the following general formula (2): [ka] [In general formula (2), R 11 , R 12 and R 13 each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group, R 11 , R 12 and R 13 at least one of X is a substituted or unsubstituted alkyl group; 1 represents a group consisting of a combination of one or more groups selected from the group consisting of an alkynyl group, an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom; m1 is an integer of 1 to 8; and n1 is an integer of 0 to 7; m1+n1 is an integer from 1 to 8.

[10] The photon upconversion composition according to [9], wherein n1 in the general formula (2) is 1 or more.

[11] A film comprising the photon upconversion composition according to any one of [1] to

[10] .

[12] A transparent product for suppressing myopia, comprising the photon upconversion composition according to any one of [1] to

[10] or the film according to

[11] .

[13] A method for converting visible light into ultraviolet light by irradiating the photon upconversion composition according to any one of [1] to

[10] or the film according to

[11] with visible light.

[14] The method according to

[13] , wherein the ultraviolet light emission is observed in the range of 360 to 400 nm.

[15] A compound represented by the following general formula (1'): [ka] [In the general formula (1'), R 1 ', R 2 ' and R 3 Each ' independently represents a substituted or unsubstituted alkyl group, R 1 ', R 2 ' and R 3 The total number of carbon atoms in X' is 6 or more, X' represents a group consisting of one or more groups selected from the group consisting of alkynyl groups, alkenyl groups, alkyl groups, aromatic ring groups, heteroaromatic ring groups, alkoxy groups, carboxyl groups, cyano groups, and halogen atoms, m' is an integer of 1 to 8, n' is an integer of 0 to 7, and m' + n' is an integer of 1 to 8.] [Effects of the Invention]

[0007] According to the present invention, a photon upconversion composition can be realized that can efficiently convert excitation light into ultraviolet light with a lower excitation light intensity. By using this photon upconversion composition as a light irradiation target in a method of irradiating visible light and converting it into ultraviolet light, ultraviolet light can be efficiently generated even with weak irradiation light such as sunlight or indoor lighting. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating the UC light emission mechanism of the photon upconversion composition of the present invention. [Figure 2] 1 shows the UC emission spectrum of a tetrahydrofuran solution (composition 1) in which compound A1 and compound D1 are dissolved, excited by 445 nm light. [Figure 3] 1 is a double logarithmic graph showing the excitation light intensity dependence of UC luminescence intensity for tetrahydrofuran solutions (compositions 1 and 2) in which compound A1 and compound D1 are dissolved. [Figure 4] 1 shows UC emission spectra of a tetrahydrofuran solution in which Compound A1 and Compound D1 are dissolved (Composition 1), and a tetrahydrofuran solution in which only Compound A1 is dissolved (Compound A1 solution) under simulated sunlight. [Figure 5] 1 shows UC emission spectra of a tetrahydrofuran solution (composition 1) in which compound A1 and compound D1 are dissolved, and a tetrahydrofuran solution (solution of compound A1) in which only compound A1 is dissolved, under LED light. [Figure 6] 1 is a UC emission spectrum of film 1 containing compound A1, compound D1, and polystyrene. [Figure 7] 1 is a UC emission spectrum of film 2 containing compound A1, compound D1, and poly(methyl methacrylate). [Figure 8] 1 is a UC emission spectrum of film 3 containing compound A1, compound D1, and poly(N-isopropylacrylamide). [Figure 9] 1 shows the UC emission spectra of film 4 containing compound A1, compound D1, and poly(butyl acrylate). [Figure 10] 1 is a UC emission spectrum of film 5 containing compound A1 and compound D1. [Figure 11] 1 is a UC emission spectrum of Film 6 containing Compound A1, Compound D1, polyvinyl alcohol, and Pluronic F127. [Figure 12] 1 is a UC emission spectrum of Film 7 containing Compound A1, Compound D1, polyvinyl alcohol, and TX-100. [Figure 13] 1 shows the UC emission spectrum of a microporous film (film 8) impregnated with a solution of compound A1 and compound D1. [Figure 14]1 shows the UC emission spectrum of a microporous film (film 9) impregnated with a liquid material in which compound D1 is dissolved in a melt of compound A1. [Figure 15] 1 shows the UC emission spectrum of a tetrahydrofuran solution of Compound A3 and Compound D1 (Composition 4). [Figure 16] 1 is a graph showing the time dependence of UC luminescence of Composition 4 after irradiation with excitation light has been stopped. [Figure 17] 1 shows the UC emission spectrum of a tetrahydrofuran solution of Compound A4 and Compound D1 (Composition 5). [Figure 18] 1 shows the UC emission spectrum of a tetrahydrofuran solution of Compound A5 and Compound D1 (Composition 6). [Figure 19] 1 shows the UC emission spectrum of a tetrahydrofuran solution of Compound A6 and Compound D1 (Composition 7). DETAILED DESCRIPTION OF THE INVENTION

[0009] The present invention will be described in detail below. The following description of the constituent elements may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. In addition, the isotopes of hydrogen atoms present in the molecules of the compounds used in the present invention are not particularly limited, and for example, when all hydrogen atoms in the molecule are 1 H, or part or all of 2 It may also be H (deuterium D).

[0010] <Photon upconversion composition> The photon upconversion composition of the present invention comprises a naphthalene compound substituted with a substituent containing at least one selected from the group consisting of an alkynyl group, a substituted silyl group, a benzene ring, a heteroaromatic ring, a cyano group, and a halogen atom. In the present invention, the term "photon upconversion composition" refers to a composition that exhibits the ability to convert light irradiated thereon (irradiated light) into light of a shorter wavelength. The source light to be converted into "shorter wavelength light" is light in a wavelength range longer than the ultraviolet range that excites at least one component of the photon upconversion composition, and is preferably visible light. Here, "light that excites a component" can be selected from light whose emission peak wavelength range overlaps with the wavelength range in which the component exhibits optical absorption, and in the following explanation, this will be referred to as "excitation light" for that component. Furthermore, the "shorter wavelength light" to be converted is preferably ultraviolet light. That is, a preferred embodiment of the "photon upconversion composition" of the present invention is a composition that exhibits the ability to convert visible light into ultraviolet light. Herein, "visible light" means light having a wavelength in the range of more than 400 nm and not more than 800 nm, and "ultraviolet light" means light having a wavelength in the range of 200 nm to 400 nm. The ultraviolet light contained in the source light and the converted light may be a single light or a composite light containing multiple lights with different maximum emission wavelengths. The source light may contain visible light and non-visible light, and the converted light may contain ultraviolet light and non-ultraviolet light.

[0011] In the following description, the conversion of irradiated light into light with a shorter wavelength by a photon upconversion composition and the resulting light emission will be referred to as "photon upconversion luminescence" or "UC luminescence," light emitted by photon upconversion luminescence (light with a shorter wavelength than the irradiated light) will be referred to as "UC light," and the "photon upconversion composition of the present invention" will sometimes be simply referred to as the "composition of the present invention." The UC emission of the photon upconversion composition of the present invention is derived from the emission of the naphthalene compound contained in the composition. The naphthalene compound used in the present invention has a high lowest excited singlet energy level, and is therefore capable of emitting ultraviolet light upon deactivation from the excited singlet state. The naphthalene compound used in the present invention is also characterized by being substituted with at least one substituent selected from the group consisting of an alkynyl group, a substituted silyl group, a benzene ring, a heteroaromatic ring, a cyano group, and a halogen atom. Because the naphthalene compound is substituted with such a substituent, the probability of generation of an excited singlet state by triplet-triplet annihilation, f, and the fluorescence quantum yield, Φ, are significantly increased. FA The photon upconversion luminescence obtained from the composition is photon upconversion luminescence due to triplet-triplet annihilation, and can be confirmed by the fact that the lifetime of the photon upconversion luminescence is delayed fluorescence on the order of milliseconds and that the slope of the log-log plot of the photon upconversion luminescence intensity as a function of excitation light intensity changes from 2 to 1. In the following description, "an alkynyl group, a substituted silyl group, a benzene ring, a heteroaromatic ring, a cyano group, and a halogen atom" may be referred to as a "specific group," and "a substituent containing at least one selected from the group consisting of an alkynyl group, a substituted silyl group, a benzene ring, a heteroaromatic ring, a cyano group, and a halogen atom" may be referred to as a "specific group-containing substituent." The structure of the naphthalene compound used in the present invention will be explained in detail below.

[0012] [Naphthalene compounds] The naphthalene compound of the present invention is a compound containing a naphthalene skeleton. The naphthalene skeleton here means a ring in which no other rings are fused to a naphthalene ring. Therefore, a skeleton of three or more rings in which other rings are fused to a naphthalene ring is not included in the naphthalene skeleton here. First, the specific group contained in the substituent of the naphthalene compound will be described. The alkynyl group in the substituent may be linear, branched, or cyclic. The alkynyl group preferably has 2 to 20 carbon atoms, more preferably 2 to 10, and even more preferably 2 to 6. Examples include an ethynyl group, a propynyl group, and a butynyl group. The substituted silyl group may be a mono-substituted silyl group, a di-substituted silyl group, or a tri-substituted silyl group, but is preferably a tri-substituted silyl group. In the di-substituted silyl group and the tri-substituted silyl group, the multiple substituents may be the same or different. Examples of the substituent of the substituted silyl group include an alkyl group and an aromatic ring group. The alkyl group may be linear, branched, or cyclic, but is preferably linear or branched. The number of carbon atoms in the alkyl group may be 1 or more, but is preferably 2 or more, and more preferably 3 or more. Furthermore, when the substituted silyl group is a trialkylsilyl group, the total number of carbon atoms in the three alkyl groups is preferably 6 or more. There is no particular upper limit on the number of carbon atoms, but it is preferably 20 or less. For a description of the aromatic ring group, a preferred range, and specific examples, please refer to the description of the aromatic ring group as the second substituent below. Specific examples of the substituted silyl group include a trimethylsilyl group, a triethylsilyl group, a tri-n-propylsilyl group, a triisopropylsilyl group, and a triphenylsilyl group. The benzene ring may be a monocyclic ring contained in a substituent, or may constitute at least a part of a fused polycyclic structure contained in a substituent. That is, a cyclic structure may be fused to at least one side of the benzene ring. The cyclic structure fused to the benzene ring may be any of an aromatic ring (aromatic hydrocarbon ring), an aromatic heterocyclic ring, an alicyclic hydrocarbon ring, and an alicyclic heterocyclic ring. Furthermore, it is preferable that the benzene ring constitutes an aromatic ring group (aryl group) as a monocyclic ring, or forms a fused polycyclic structure with another aromatic ring to constitute an aromatic ring group (aryl group). The number of carbon atoms in the aromatic ring group is preferably 6 to 22, more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10. Specific examples of the aromatic ring group include a phenyl group, a naphthalenyl group, and a biphenyl group. The heteroaromatic ring may be a monocycle or a fused ring in which one or more heterocycles are fused with one or more aromatic rings or heterocycles. The heterocycle in the fused ring may be a heteroaromatic ring or an alicyclic heterocycle, as long as the fused ring as a whole has aromaticity. The heteroaromatic ring preferably has 3 to 40 carbon atoms, more preferably 5 to 22 carbon atoms, even more preferably 5 to 18 carbon atoms, even more preferably 5 to 14 carbon atoms, and particularly preferably 5 to 10 carbon atoms. Examples of heteroatoms constituting the heterocycle include a nitrogen atom, an oxygen atom, and a sulfur atom. Specific examples of the heteroaromatic ring include a pyridine ring, a pyridazine ring, a pyrimidine ring, a triazole ring, and a benzotriazole ring. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkynyl group, the substituent of the substituted silyl group, the benzene ring, and the heteroaromatic ring in the substituent may be substituted with a substituent (hereinafter referred to as a "second substituent"). Examples of the second substituent include an alkynyl group, a substituted silyl group, a cyano group, and a halogen atom, as well as an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, and a pinacolatoboryl group. These second substituents may be further substituted with a third substituent. For explanations, preferred ranges, and specific examples of the alkynyl group, the substituted silyl group, and the halogen atom, please refer to the descriptions of the alkynyl group, the substituted silyl group, and the halogen atom in the above substituent.

[0013] The alkenyl group as the second substituent may be linear, branched, or cyclic. It preferably has 2 to 20 carbon atoms, more preferably 2 to 10, and even more preferably 2 to 6. Examples include an ethenyl group, a propenyl group, and a butenyl group. The alkyl group may be linear, branched, or cyclic. The number of carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. Examples include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. The alkyl group bonded to the oxy group of the alkoxy group may be linear, branched, or cyclic. The number of carbon atoms is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, and an isopropoxy group. For the description, preferred range, and specific examples of the aromatic ring group, reference can be made to the description of the aromatic ring group constituted by a benzene ring in the above-mentioned substituent. For the description, preferred range, and specific examples of the heteroaromatic ring constituting the heteroaromatic ring group, reference can be made to the description of the heteroaromatic ring in the above-mentioned substituent.

[0014] The naphthalene compound used in the present invention is substituted with a substituent (specific group-containing substituent) containing at least one selected from the group consisting of the above-mentioned alkynyl group, substituted silyl group, benzene ring, heteroaromatic ring, cyano group, and halogen atom (all of which are referred to as specific groups). The specific group-containing substituent may be a substituent having a structure in which the specific group is bonded to the naphthalene ring via a single bond, or a substituent having a structure in which the specific group is bonded to the naphthalene ring via a linking group. The specific group-containing substituent may contain only one of the group consisting of specific groups, or may contain two or more of them. Examples of substituents containing two or more of the group consisting of specific groups include a substituent having a structure in which a specific group is bonded to another specific group via a single bond (a structure in which a specific group is substituted with another specific group), or a substituent having a structure in which a specific group is linked to another specific group via a linking group. The specific group-containing substituent may be composed solely of the specific group, or may contain groups other than the specific group. Examples of the substituent containing a specific group and a group other than the specific group include a substituent having a structure in which a specific group is linked to a naphthalene ring via a linking group, where the linking group is a group other than the specific group, and a substituent having a structure in which a specific group is substituted with a substituent, where the substituent is a group other than the specific group. Examples of groups other than the specific group include an alkenyl group, an alkyl group, an alkoxy group, and a carboxyl group. For explanations, preferred ranges, and specific examples of the alkenyl group, alkyl group, and alkoxy group, please refer to the descriptions of the alkenyl group, alkyl group, and alkoxy group as the second substituent.

[0015] In the naphthalene compound used in the present invention, the number of specific group-containing substituents substituted on the naphthalene ring may be one or two or more. The number of specific group-containing substituents substituted on the naphthalene ring is preferably two to four. When the number of specific group-containing substituents is two or more, the multiple specific group-containing substituents may be the same or different. The substitution positions of the specific group-containing substituent on the naphthalene ring are not particularly limited, but are preferably at least the 1st and 4th positions, and more preferably only the 1st and 4th positions. In other words, the naphthalene compound used in the present invention is more preferably a 1,4-disubstituted naphthalene. Furthermore, the substitution positions of the specific group-containing substituent on the naphthalene ring may be the 1st and 5th positions. Furthermore, when the number of specific group-containing substituents substituted on the naphthalene ring is 7 or less, the substitutable positions (hydrogen atoms of methylene groups) of the naphthalene ring that are not substituted with the specific group-containing substituents may be substituted with a substituent other than the specific group-containing substituent. Preferred examples of the substituent other than the specific group-containing substituent include an alkenyl group, an alkyl group, an alkoxy group, and a carboxyl group. For explanations, preferred ranges, and specific examples of the alkenyl group, alkyl group, and alkoxy group, please refer to the descriptions of the alkenyl group, alkyl group, and alkoxy group as the second substituent.

[0016] The naphthalene compound used in the present invention preferably has at least one of a substituted silyl group, an alkynyl group, and a substituted or unsubstituted phenyl group. Among these, the introduction of an alkynyl group, in particular, gives the naphthalene compound a rigid structure. This suppresses non-radiative deactivation of triplet excitons, which is advantageous for improving the probability f of generating a singlet excited state through triplet-triplet annihilation. The alkynyl group may be bonded to the naphthalene ring via a single bond, or may be linked to the naphthalene ring via a linking group such as a phenylene group. That is, the alkynyl group may constitute, for example, an alkynylphenyl group.

[0017] The naphthalene compound used in the present invention preferably has a structure represented by the following general formula (1). [ka]

[0018] In general formula (1), R 1 , R 2 and R 3 R each independently represents a substituted or unsubstituted alkyl group. 1 , R 2 and R 3 may be the same or different. 1 , R 2 and R 3 The alkyl group in may be linear, branched, or cyclic, but is preferably linear or branched. The number of carbon atoms in the alkyl group may be 1 or more, or 2 or more, but is preferably 2 or more, and more preferably 3 or more. In addition, R 1 , R 2 and R 3 The total number of carbon atoms in each of the alkyl groups is preferably 6 or more. There is no particular upper limit on the number of carbon atoms, but it is preferably 20 or less for each alkyl group. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, and an isopropyl group. When the alkyl group is a substituted alkyl group, examples of the substituent include an alkynyl group, an alkenyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom. For explanations of these, preferred ranges, and specific examples, please refer to the descriptions of the corresponding groups represented by X.

[0019] X represents a group formed by combining one or more groups selected from the group consisting of an alkynyl group, an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom. The group represented by X may consist of only one group selected from this group, or may be a group formed by combining two or more groups selected from this group. A group formed by combining two or more groups (multiple groups) selected from this group is, for example, a group having a structure in which any one group of the multiple groups is substituted with at least one remaining group. The number of groups substituted on any one of the multiple groups may be one or more. Here, when X contains an alkynyl group or an alkenyl group, it is preferable that the alkynyl group or alkenyl group is not directly bonded to an alkoxy group, a cyano group, or a halogen atom. Furthermore, X preferably represents a group formed by combining one or more groups selected from the group consisting of an alkynyl group, an alkyl group, an aromatic ring group, and a heteroaromatic ring group. It is more preferable that X represents a group formed by combining one or more groups selected from the group consisting of an alkynyl group, an alkyl group, and an aromatic ring group. X is preferably a substituted or unsubstituted alkylalkynyl group, a substituted or unsubstituted arylalkynyl group, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, and the substituent here is preferably an alkylalkynyl group, an arylalkynyl group, an alkyl group, an aryl group, a heteroaryl group, a cyano group, or a halogen atom, more preferably an alkylalkynyl group, an arylalkynyl group, an alkyl group, or an aryl group. Note that two or more Xs do not bond together to form a cyclic structure. For an explanation, a preferred range, and specific examples of the alkynyl group, reference can be made to the description of the alkynyl group in the above-mentioned substituent. For an explanation, a preferred range, and specific examples of the alkenyl group, alkyl group, aromatic ring group, heteroaromatic ring group, and alkoxy group, reference can be made to the descriptions of the alkenyl group, alkyl group, aromatic ring group, heteroaromatic ring group, and alkoxy group as the above-mentioned second substituent.

[0020] m represents the number of tri-substituted silylethynyl groups bound by m substituting on the naphthalene ring, and is an integer of 1 to 8. m is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and can be selected, for example, from the range of 1 to 2, or from the range of 2 to 4. When m is an integer of 2 or greater, the tri-substituted silylethynyl groups bound by m may be the same or different. The substitution positions on the naphthalene ring of the tri-substituted silylethynyl groups bound by m are preferably at least the 1st and 4th positions, and more preferably only the 1st and 4th positions. Furthermore, the substitution positions on the naphthalene ring of the tri-substituted silylethynyl groups bound by m may be the 1st and 5th positions. n represents the number of Xs substituted on the naphthalene ring and is an integer between 0 and 7. However, m+n is an integer between 1 and 8. When n is an integer between 2 and 8, the Xs may be the same or different. n is preferably an integer between 0 and 6, more preferably between 0 and 4. For example, it can be selected from the range of 0 to 2, or it can be 0 or 1. n is also preferably 0. Furthermore, n is also preferably 1 or greater. Compounds of general formula (1) in which n is 1 or greater, i.e., compounds in which the naphthalene ring is substituted with a substituent X, maintain adequate intermolecular spacing even at high concentrations due to the steric hindrance of the substituent, thereby achieving high fluorescence quantum yields. Such compounds are advantageous when mixed at high concentrations with resins such as epoxy resins, polystyrenes, and polymethyl methacrylates. From this perspective, X is preferably a bulky substituent such as a branched alkyl group. Preferred examples of the branched alkyl group include branched alkyl groups having 3 to 6 carbon atoms, such as an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, and an isohexyl group, and a tert-butyl group is more preferred.

[0021] The naphthalene compound used in the present invention preferably has a structure represented by the following general formula (2). [ka]

[0022] In general formula (2), R 11 , R 12 and R 13 each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group, R 11 , R 12 and R 13 At least one of R is a substituted or unsubstituted alkyl group. 11 , R 12 and R 13 Among these, there may be one or two substituted or unsubstituted alkyl groups, and R 11 , R 12 and R 13 All of R may be substituted or unsubstituted alkyl groups. 11 , R 12 and R 13 When two or more of R are substituted or unsubstituted alkyl groups, the multiple substituted or unsubstituted alkyl groups may be the same or different. 11 , R 12 and R 13 For details of the substituted or unsubstituted alkyl group, the preferred range, and specific examples, see R in general formula (1). 1 , R 2 and R 3 The explanation, preferred ranges and specific examples of the substituted or unsubstituted alkyl group represented by can be referred to. In general formula (2), X 1 represents a group consisting of one or more groups selected from the group consisting of alkynyl groups, alkenyl groups, alkyl groups, aromatic ring groups, heteroaromatic ring groups, alkoxy groups, carboxyl groups, cyano groups, and halogen atoms, m1 is an integer of 1 to 8, n1 is an integer of 0 to 7, and m1+n1 is an integer of 1 to 8. X 1 For an explanation of m1 and n1, please refer to the explanation of X in general formula (1), and for an explanation of m1 and n1, please refer to the explanation of m and n in general formula (1), respectively. The compound represented by general formula (2) is characterized by excellent long-term stability and long-lasting effects, and in this respect is superior to the compound represented by general formula (1).

[0023] Specific examples of naphthalene compounds are given below, but the naphthalene compounds that can be used in the present invention should not be construed as being limited to these specific examples. [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka] [ka]

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[0024] The photon upconversion composition of the present invention may contain only one type of naphthalene compound substituted with a specific group-containing substituent, or may contain two or more types. The photon upconversion composition of the present invention may also contain a naphthalene compound substituted with a specific group-containing substituent and components (other components) other than the naphthalene compound substituted with a specific group-containing substituent. Examples of other components include a donor compound (sensitizer) that absorbs light and transfers energy to the naphthalene compound. In the following description, when a photon upconversion composition contains a donor compound, the naphthalene compound substituted with a specific group-containing substituent contained in the composition is referred to as an "acceptor compound." In a photon upconversion composition containing an acceptor compound and a donor compound, photon upconversion luminescence is presumed to occur due to triplet-triplet annihilation, for example, according to the mechanism shown in Figure 1. The mechanism of this UC luminescence is explained below. Here, the donor compound is excited at its lowest singlet energy level S 1,D is the lowest excited triplet energy level S of the acceptor compound 1,A lower than its lowest excited triplet energy level T 1,D is the lowest excited triplet energy level T of the acceptor compound 1,A The excitation light for the donor compound is used as the light irradiating the composition. In Figure 1, "ISC" indicates intersystem crossing, "TET" indicates triplet energy transfer from the donor compound to the acceptor compound, and "TTA" indicates triplet-triplet annihilation. First, when excitation light is irradiated onto a photon upconversion composition containing an acceptor compound and a donor compound, the donor compound molecule (donor molecule) absorbs the light and transitions to an excited singlet state (S 1,D ), then intersystem crossing occurs to the excited triplet state (T 1,D The energy of the donor molecule in the excited triplet state is transferred to the acceptor molecule. This results in the excited triplet state (T 1,A ), the triplet states of the two molecules meet, causing triplet-triplet annihilation, and one of the molecules enters the excited singlet state (S 1,A ) transition occurs. In other words, photon upconversion occurs due to triplet-triplet annihilation of the acceptor molecule. The acceptor molecule thus reaches an excited singlet state, emitting fluorescence (UC light) and becoming inactivated, causing the composition to emit UC light. At this time, the excited singlet state (S 1,A ) has a very high energy level, so UC light with higher energy (shorter wavelength) than the excitation light can be obtained by radiative deactivation from its excited singlet state.

[0025] [Donor compound] The donor compound used in the photon upconversion composition of the present invention is preferably a compound that satisfies the following condition (A), and more preferably a compound that satisfies all of the following conditions (A) to (C). (A) The lowest excited singlet energy level S of the acceptor compound 1,A The lowest excited singlet energy level S is lower than 1,D and the lowest excited triplet energy level T of the acceptor compound 1,A The lowest excited triplet energy level T is higher than 1,D To have. (B) High absorbance. (C) The absorbance is low in at least the region of the ultraviolet range that overlaps with the wavelength range of UC light. The molecules of the donor compound that satisfy condition (A) are at the lowest excited singlet energy level S of the acceptor compound. 1,A The lowest excited singlet energy level S is lower than 1,D By having this property, it can be excited to the singlet state using irradiation light with a wavelength longer than that of UC light. In addition, the molecules of the donor compound that satisfy condition (A) can be excited to the lowest excited triplet energy level T of the acceptor compound. 1,A The lowest excited triplet energy level T is higher than 1,D By having this structure, the excited triplet energy can be easily transferred to the acceptor molecule, which makes the UC emission mechanism shown in Figure 1 work more reliably. The lowest excited singlet energy level S of the acceptor compound 1,A and the lowest excited singlet energy level S of the donor compound 1,D The difference (S 1,A -S 1,D ) is preferably 0.3 to 2 eV, more preferably 0.4 to 1 eV, and further preferably 0.4 to 0.8 eV. The lowest excited triplet energy level T of the donor compound 1,D and the lowest excited triplet energy level T of the acceptor compound 1,A The difference (T 1,D -T 1,A) is preferably 0.01 to 1 eV, more preferably 0.01 to 0.5 eV, and even more preferably 0.01 to 0.2 eV. Lowest excited singlet energy level S 1,A , S 1,D and the lowest excited triplet energy level T 1,A , T 1,D For the measurement method of the lowest excited singlet energy level S1 and the lowest excited triplet energy level T1, please refer to the description in the section below (Method for measuring the lowest excited singlet energy level S1 and the lowest excited triplet energy level T1). These energy levels can also be calculated by density functional theory. In addition, compounds that satisfy condition (A) as well as conditions (B) and (C) can efficiently absorb irradiated light but do not absorb UC light. Therefore, by using such compounds as donor compounds, the threshold excitation intensity I th The threshold excitation intensity I th " is the excitation light intensity at the inflection point of a double logarithmic graph showing the dependency of UC luminescence intensity on excitation light intensity. The lower this value, the lower the excitation light intensity required for UC luminescence; in other words, the more efficiently UC luminescence occurs. In condition (B), "high absorbance" means an extinction coefficient of 50,000 M -1 m -1 This means that it is more than or equal to this. In condition (C), "low absorbance" means an extinction coefficient of 40,000 M -1 cm -1 This means that:

[0026] Specific examples of donor compounds are given below, but the donor compounds that can be used in the present invention should not be construed as being limited to these specific examples. [ka]

[0027] Among these compounds, compound D1 is preferred as a donor compound because it exhibits a large extinction coefficient and has extremely low absorbance in the wavelength range of the UC emission of the naphthalene compound used in the present invention. In addition to these compounds, organic donor compounds that do not contain metal elements can also be preferably used. As the organic donor compound, a thermally activated delayed fluorescent material is particularly preferred. The thermally activated delayed fluorescent material can be appropriately selected from those that have traditionally been used as donors in photon upconversion compositions.

[0028] (Method for measuring the lowest excited singlet energy level S1 and the lowest excited triplet energy level T1) The lowest excited singlet energy level S1 of the compound used in the present invention can be obtained by dissolving the compound, measuring its fluorescence spectrum, and converting the wavelength of the shortest fluorescence peak into an energy value using the following conversion formula: The lowest excited triplet energy level T1 of the compound used in the present invention can be obtained by dissolving the compound, measuring its phosphorescence spectrum, and converting the wavelength of the phosphorescence peak into an energy value using the following conversion formula: The solvent used to dissolve the compound should be one that can dissolve the compound (e.g., tetrahydrofuran). The concentration of the solution should be such that spectra can be measured (e.g., 100 μM). The emission spectrum can be measured using a JASCO FP-8300 spectrometer manufactured by JASCO Corporation, using a xenon lamp as the excitation light source. Conversion formula: S1[eV]=1239.85 / λ F Conversion formula: T1[eV]=1239.85 / λ P In the above equation, λ F is the fluorescence peak wavelength [nm], and λ P is the phosphorescence peak wavelength [nm].

[0029] [Ratio of acceptor compound and donor compound] When the photon upconversion composition contains a naphthalene compound (acceptor compound) substituted with a specific group-containing substituent and a donor compound, the molar ratio of the donor compound to the acceptor compound [(number of moles of donor compound / number of moles of acceptor compound) × 100] is preferably 0.01 to 20%, more preferably 0.1 to 10%, and even more preferably 1 to 5%. When the donor compound has low absorbance at the emission wavelength of the acceptor compound, the concentration of the donor compound can be increased to allow for better absorption of excitation light.

[0030] [Other components other than the donor compound] The photon upconversion composition of the present invention may further contain other components, such as a solvent for dissolving the naphthalene compound (acceptor compound) substituted with a specific group-containing substituent and the donor compound, a matrix material such as a polymer for maintaining these compounds in a dispersed state in a solid, and additives such as a surfactant. Solvents and polymers can be appropriately selected from known solvents. Examples of solvents include dimethylformamide, tetrahydrofuran, chloroform, and mixtures thereof. Examples of polymers include polystyrene, poly(alkyl methacrylate), poly(alkyl acrylate), poly(N-alkylacrylamide), and polyvinyl alcohol, as well as bioplastics. Bioplastics contain materials derived from renewable organic resources as raw materials and can be appropriately selected from chemically or biologically synthesized materials. For example, cellulose and protein can be used, with biodegradable biopolymers being particularly preferred. In the present invention, two or more of these polymers may be mixed and used. The polymer may have a glass transition temperature above room temperature (25°C) or below room temperature. When a polymer with a glass transition temperature above room temperature is used as a matrix material, the film exhibits a rigid property, making molecular diffusion difficult, and energy transfer between compound molecules occurs primarily through energy diffusion. Furthermore, when a polymer having a glass transition temperature below room temperature is used as the matrix material, the film exhibits soft properties, and energy transfer by molecular diffusion may occur. The glass transition temperature of the polymer can be measured by a differential scanning calorimeter. The method for dispersing the naphthalene compound of the present invention or the donor compound in the polymer is not particularly limited. For example, they may be dispersed through a process of dissolving and mixing them in a common solvent, or a solution obtained by dissolving the naphthalene compound of the present invention or the donor compound in a non-volatile solvent may be dispersed in the polymer. The non-volatile solvent may be any non-volatile liquid that dissolves the compound well, and a surfactant (e.g., Triton) may be used. R X-100) or a low molecular weight organic solvent (for example, hexadecane) can be appropriately selected and used. When the photon upconversion composition contains a solvent, the proportion of the naphthalene compound relative to the total amount of the composition is preferably 0.005 to 5 wt %, more preferably 0.05 to 5 wt %, and even more preferably 0.5 to 1 wt %. When the photon upconversion composition contains a polymer, the proportion of the naphthalene compound relative to the total amount of the composition is preferably 0.1 to 80% by weight, more preferably 1 to 80% by weight, and even more preferably 10 to 50% by weight.

[0031] [Usefulness of photon upconversion compositions] The photon upconversion composition of the present invention can efficiently convert irradiated light such as visible light into ultraviolet light and emit the light at a lower excitation light intensity. th Therefore, even with weak light such as sunlight or indoor lighting, the photon upconversion mechanism can work and ultraviolet light can be emitted as UC light. Therefore, the photon upconversion composition of the present invention is useful as a source of ultraviolet light and can effectively contribute to improving the efficiency in various situations where ultraviolet light is used. For example, by applying a film of the photon upconversion composition of the present invention to a transparent body such as transparent glass or a transparent resin board and exposing it to sunlight, ultraviolet light can be obtained inexpensively. When the ultraviolet light is used to activate a photocatalyst, the photocatalyst can be activated energy-efficiently, thereby improving the efficiency of artificial photosynthesis and other processes that utilize the photocatalyst. For example, this can significantly contribute to improving the fuel efficiency of fuel cell vehicles, which use a photocatalyst to produce hydrogen from water and sunlight and then use that hydrogen to generate electricity in a fuel cell. The transparent body to which the film is applied may be any body that can transmit at least a portion of UC light (preferably 10% or more, more preferably 50% or more, even more preferably 90% or more, and particularly preferably 99% or more), and may transmit at least a portion of UC light in a wavelength range of particular interest. When applying the film to a transparent body, it may be directly attached to the surface of the transparent body, laminated on the surface of the transparent body, or detachably stacked on the surface of the transparent body. It may also be sandwiched between two transparent bodies. Furthermore, if a lens with a light-concentrating function is selected as the transparent body, the application of the film can concentrate UC light at a specific spot, thereby achieving more efficient energy utilization. Furthermore, it has been medically proven that ultraviolet light in the 360-400 nm range (violet light) has a myopia-suppressing effect. Therefore, films emitting UC light, including ultraviolet light in the 360-400 nm range, can be used to suppress myopia. For example, by applying such films to windows, eyeglasses, goggles, contact lenses, etc., sunlight or indoor light striking the film is converted into ultraviolet light, thereby effectively suppressing myopia in people (especially children and students) and animals. Furthermore, by applying such films to LED lights, smartphones, personal computers, and television displays, these illumination lights can be converted into ultraviolet light, effectively suppressing myopia in the operator. The photon upconversion composition of the present invention is also useful as a film that generates such ultraviolet light in the 360-400 nm range. Products exhibiting a myopia-suppressing effect may be produced by applying such films to transparent materials, or by mixing the naphthalene compounds of the present invention with transparent materials such as transparent resins to form transparent products such as windows, eyeglasses, goggles, contact lenses, and light-transmitting plates. As described above, the photon upconversion composition of the present invention is applicable to a wide range of transparent products such as films, lenses, and transparent plates, and is useful for producing myopia-suppressing transparent products. Note that "transparent" here means that the composition transmits at least light of 360 nm to 400 nm and light necessary for causing photon upconversion.

[0032] <Compound represented by general formula (1')> Among the naphthalene compounds used in the present invention, the compound represented by the following general formula (1') is a novel compound. [ka] In general formula (1′), R 1 ', R 2 ' and R 3 Each ' independently represents a substituted or unsubstituted alkyl group, R 1 ', R 2 ' and R 3The total number of carbon atoms in X' is 6 or more, X' represents a group consisting of one or more groups selected from the group consisting of an alkynyl group, an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom, m' is an integer of 1 to 8, n' is an integer of 0 to 7, and m'+n' is an integer of 1 to 8. R in general formula (1') 1 ', R 2 ' and R 3 The description of X', m', and n', their preferred ranges, and specific examples are given in the general formula (1). 1 , R 2 and R 3 , X, m, n can be referred to. 1 ', R 2 ' and R 3 The total number of carbon atoms in ' is 6 or more.

[0033] <Method for synthesizing a compound represented by general formula (1')> The compound represented by general formula (1') can be synthesized by combining known reactions. For example, a compound in which the 1st and 4th positions of the naphthalene ring are substituted or unsubstituted trialkylsilylethynyl groups can be synthesized by reacting the following two compounds: [ka]

[0034] R in the above reaction equation 1 '~R 3 For an explanation of "", refer to the corresponding description in general formula (1'). Z represents a halogen atom, such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, with a chlorine atom, a bromine atom, or an iodine atom being preferred. The above reaction is an application of a known coupling reaction, and known reaction conditions can be appropriately selected and used. For details of the above reaction, please refer to the synthesis examples described below. In addition, the compound represented by general formula (1') can also be synthesized by combining other known synthesis reactions.

[0035] <Film> Next, the film of the present invention will be described. The films of the present invention comprise the photon upconversion compositions of the present invention. For a description of the photon upconversion composition of the present invention, please refer to the description in the <Photon upconversion composition> section above. Examples of the film of the present invention include a film formed from the photon upconversion composition and a layer formed from the photon upconversion composition on a substrate. In the latter embodiment, the film may be composed solely of the layered photon upconversion composition, or may be composed of the layered photon upconversion composition and the substrate. The method for forming the photon upconversion composition into a film is not particularly limited, and known film forming methods such as calendar molding, extrusion molding, and inflation molding can be used. The method for forming the photon upconversion composition into a layer is also not particularly limited, and either a dry process or a wet process can be used. The substrate is also not particularly limited, and for example, a substrate made of glass, transparent plastic, quartz, silicon, etc. can be used. The photon upconversion composition used in the film is preferably one containing a naphthalene compound substituted with a specific group-containing substituent and a polymer, or one containing a naphthalene compound (acceptor compound) substituted with a specific group-containing substituent, a donor compound, and a polymer, because these compositions facilitate molding and film formation and allow for control of the mechanical properties of the film. The polymer used in the composition can be appropriately selected from known polymers for films, such as polystyrene, poly(alkyl acrylate), poly(alkyl methacrylate), poly(N-alkylacrylamide), epoxy resin, and polyvinyl alcohol. When using a hydrophilic polymer such as polyvinyl alcohol, it is preferable to add a surfactant to the composition to improve the dispersibility of the compound. The film of the photon upconversion composition may be a single layer or a multilayer. When the film is a multilayer film, it is preferred that at least adjacent layers thereof have different compositions.

[0036] Another embodiment of the film of the present invention is an impregnated film obtained by impregnating a porous film with a liquid material of a naphthalene compound substituted with a specific group-containing substituent. Examples of the liquid material include a solution of a naphthalene compound substituted with a specific group-containing substituent, a solution of a naphthalene compound (acceptor compound) substituted with a specific group-containing substituent and a donor compound, a melt obtained by heating and melting a naphthalene compound substituted with a specific group-containing substituent, and a melt obtained by heating a mixture of a naphthalene compound (acceptor compound) substituted with a specific group-containing substituent and a donor compound. The melt obtained by heating the mixture may be a dispersion of a solid donor compound in a melt of the acceptor compound, or a melt in which both the acceptor compound and the donor compound are in a molten state. Of these, a solution-impregnated film is preferred because it is easier to obtain a stable product. As the porous film, an organic porous film in which an organic filler is dispersed in a matrix polymer can be used. Commercially available products include microporous films (manufactured by 3M). In addition, a PTFE membrane film (manufactured by Tokyo Glass Instruments Co., Ltd.), a polyethylene porous sheet (manufactured by Fluorochemical Co., Ltd.), etc. can also be used.

[0037] The thickness of the film of the present invention is preferably 10 nm to 1 cm, more preferably 100 nm to 500 μm, and even more preferably 1 μm to 100 μm. When the photon upconversion composition has a multilayer structure, the total thickness thereof is within the above thickness range.

[0038] Furthermore, the film of the present invention may be composed solely of a film containing the photon upconversion composition of the present invention, or may have other layers or films. Examples of other films include oxygen barrier films. When using an oxygen barrier film, it is preferable to cover and seal the entire film containing the photon upconversion composition with the oxygen barrier film. The oxygen barrier film may be a polyvinyl alcohol film or a film of a copolymer of vinyl alcohol and another monomer, and for example, an ethylene-vinyl alcohol copolymer film may be preferably used.

[0039] <Method of converting visible light to ultraviolet light> Next, a method for converting visible light into ultraviolet light will be described. The method of the present invention for converting visible light into ultraviolet light is a method of converting visible light into ultraviolet light by irradiating the photon upconversion composition of the present invention or the film of the present invention with visible light. For a description of the photon upconversion composition of the present invention and the definitions of visible light and ultraviolet light, please refer to the description in the <Photon Upconversion Composition> section above, and for a description of the film of the present invention, please refer to the description in the <Film> section above. To convert visible light to ultraviolet light using the method of the present invention, first, visible light is irradiated onto the photon upconversion composition of the present invention or the film of the present invention. The irradiated visible light may be a single light having an emission maximum wavelength at a specific wavelength in the visible region, a composite light obtained by combining multiple visible light beams with different emission maximum wavelengths, or a composite light obtained by combining light beams with continuous wavelengths in the visible region. Furthermore, the light irradiated onto the composition may contain light other than visible light in addition to visible light. Examples of irradiation sources include sunlight, LEDs, Xe lamps, and lasers. The irradiation intensity is 0.1 to 1000 mW / cm. 2 It is preferable that the intensity is 0.5 to 100 mW / cm 2 More preferably, it is 1 to 50 mW / cm 2The irradiation time is not particularly limited, and may be, for example, 1 minute or more. In the method of the present invention, irradiation with such visible light causes the photon upconversion composition of the present invention or the film of the present invention to emit ultraviolet light as UC light. This emission may occur in the ultraviolet region (wavelength range of 200 to 400 nm), but ultraviolet emission is preferably observed in the range of 360 to 400 nm. Here, "ultraviolet emission observed in the range of 360 to 400 nm" means that the ultraviolet light has a maximum emission wavelength within the range of 360 to 400 nm or has a maximum emission wavelength near 360 to 400 nm, and an emission intensity of 50% or more of the intensity at the maximum emission wavelength is observed at 360 nm or 400 nm. As described above, ultraviolet light in the range of 360 to 400 nm exhibits a myopia-suppressing effect, and thus ultraviolet light obtained in a manner in which ultraviolet emission occurs within this range can be effectively used to suppress myopia. [Example]

[0040] The features of the present invention will be explained in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, treatment details, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below. In the following examples, a spectrophotometer (JASCO: V-780) was used to measure the absorption spectrum, and a spectrofluorometer (JASCO: FP-8300) was used to measure the emission spectrum. UC efficiency η UC was calculated by the relative method using coumarin 6 as the standard substance. This relative method uses the fluorescence quantum yield of the coumarin 6 solution, the absorbance and emission spectrum of each measurement solution, the excitation light intensity during measurement, and the refractive index of the solvent, and a multichannel spectrometer (Otsuka Electronics Co., Ltd.: MCPD-9800) was used to measure the emission spectrum.

[0041] [Acceptor compounds and donor compounds used in the examples] The acceptor compounds and donor compounds used in this example are shown below. [ka]

[0042] The absorption maximum wavelength, emission maximum wavelength, lowest excited singlet energy level S1, and lowest excited triplet energy level T1 of the main absorption peaks of these acceptor and donor compounds are shown in Table 1. The acceptor's S1 was calculated from the emission maximum wavelength, and the donor's S1 was calculated from the absorption maximum wavelength. The acceptor's T1 was calculated using density functional theory (DFT), and the donor's T1 was calculated from the emission maximum wavelength.

[0043] [Table 1]

[0044] (Synthesis Example 1) Synthesis of Compound A1 [ka]

[0045] 1,4-Dibromonaphthalene (1.44 g, 5.03 mmol), bis(triphenylphosphine)palladium(II) dichloride (80.6 mg, 0.115 mmol), copper iodide (60.4 mg, 0.317 mmol), and triphenylphosphine (82.0 mg, 0.313 mmol) were dissolved in tetrahydrofuran (40 mL) under a nitrogen atmosphere, followed by the addition of diisopropylamine (36 mL). The solution was heated to 100 °C, and triisopropylsilylacetylene (3.52 g, 19.3 mmol) was added dropwise. The mixture was stirred for 10 hours. After cooling to room temperature, the tetrahydrofuran and diisopropylamine were removed under reduced pressure. The residue was extracted with chloroform. The chloroform solution was dried over sodium sulfate, and the chloroform was removed under reduced pressure. The resulting crude product was purified by column chromatography using n-hexane as a developing solvent and recrystallized from methanol. Through these steps, the target compound A1 was obtained in an amount of 1.30 g and a yield of 53%. 1 H-NMR (400 MHz, CDCl3, TMS): δ 8.41-8.38 (m, 2H), 7.63 (s, 2H), 7.61-7.58 (m, 2H), 1.20 (s, 36H), 1.19 (s, 6H). 13 C-NMR (101 MHz, CDCl3, TMS): δ 133.22, 130.14, 127.17, 126.63, 121.79, 104.77, 97.79, 18.77, 11.41. Elemental analysis, calculated for C 32 H 48 Si2: C 78.61 H 9.90; found C 78.63 H 9.94.

[0046] (Synthesis Example 2) Synthesis of Compound A3 1,4-Dibromonaphthalene (1.45 g, 5.06 mmol), bis(triphenylphosphine)palladium(II) dichloride (75.1 mg, 0.107 mmol), copper iodide (83.7 mg, 0.439 mmol), and triphenylphosphine (96.5 mg, 0.368 mmol) were dissolved in tetrahydrofuran (40 mL) under a nitrogen atmosphere, followed by the addition of diisopropylamine (40 mL). The solution was heated to 100 °C and 3,3-dimethyl-1-butyne (1.30 g, 15.8 mmol) was added dropwise. After the reaction was completed, the solution was cooled to room temperature, and the tetrahydrofuran and diisopropylamine were removed by distillation under reduced pressure. The residue was extracted with dichloromethane. The product was then subjected to silica gel column chromatography using n-hexane as a developing solvent and recrystallization from methanol. It was further purified by sublimation and recrystallization from methanol. Through the above steps, the target compound A3 was obtained in an amount of 126 mg and a yield of 8%. 1 H-NMR (400 MHz, CDCl3, TMS): δ 8.32-8.28 (m, 2H), 7.58-7.54 (m, 2H), 7.51 (s, 2H), 1.42 (s, 18H). Elemental analysis, calculated for C22 H 24 : C 91.61 H 8.39; found C 91.40 H 8.34.

[0047] (Synthesis Example 3) Synthesis of Compound A4 2,6-Di-tert-butylnaphthalene (1.21 g, 5.03 mmol) was placed in a three-neck flask and placed under a nitrogen atmosphere. While cooling to -13°C, 10 mL of dichloromethane was added, followed by bromine (0.57 mL). After stirring for 1 hour, the mixture was allowed to stand at -25°C. After 3 days, the mixture was stirred at room temperature for 8 hours and then allowed to stand at -25°C again. After 6 days, the mixture was quenched with an aqueous sodium sulfite solution and extracted with chloroform. The solvent was distilled off to obtain 1.94 g of the precursor of A4 in 96% yield. The precursor (1.20 g, 3.01 mmol), bis(triphenylphosphine)palladium(II) dichloride (50.1 mg, 0.0714 mmol), copper iodide (38.3 mg, 0.201 mmol), and triphenylphosphine (49.8 mg, 0.190 mmol) were placed in a three-neck flask and 30 mL each of tetrahydrofuran and diisopropylamine were added under a nitrogen atmosphere. The solution was heated to 100 °C and triisopropylsilylacetylene (1.44 g, 7.90 mmol) was added dropwise. After stirring overnight, the mixture was returned to room temperature. The solvent was evaporated and the residue was extracted with dichloromethane. The crude product was purified by silica gel column chromatography using n-hexane as a developing solvent, gel permeation chromatography using chloroform, and reprecipitation using methanol and n-hexane. The desired compound A4 was obtained in 324 mg (18% yield) from the above steps. 1 H-NMR (400 MHz, CDCl3, TMS): δ 8.33-8.32 (d, 2H), 7.78-7.77 (d, 2H), 1.41 (s, 18H), 1.22-1.21 (42H). Elemental analysis, calculated for C 40 H 64Si2: C 79.92 H 10.73; found C 79.66 H 10.68.

[0048] (Synthesis Example 4) Synthesis of Compound A5 1,4-Dibromonaphthalene (1.52 g, 5.33 mmol), bis(triphenylphosphine)palladium(II) dichloride (79.1 mg, 0.113 mmol), copper iodide (79.7 mg, 0.418 mmol), and triphenylphosphine (109.7 mg, 0.418 mmol) were dissolved in tetrahydrofuran (39 mL) and diisopropylamine (38 mL) under a nitrogen atmosphere. The solution was heated to 100 °C and trimethylsilylacetylene (1.52 g, 15.5 mmol) was added dropwise. After the reaction was complete, the mixture was separated using diethyl ether and aqueous ammonium chloride. The organic phase was extracted with chloroform. The organic phase was then extracted with dichloromethane, dried over anhydrous sodium sulfate, and the dichloromethane was removed under reduced pressure. The resulting crude product was purified by silica gel column chromatography using n-hexane and chloroform as developing solvents, and then recrystallized from methanol. Through these steps, the target compound A5 was obtained in an amount of 176 mg and a yield of 10%. 1 H-NMR (400 MHz, CDCl3, TMS): δ 8.35-8.31 (m, 2H), 7.62-7.58 (4H), 0.33 (s, 18H). Elemental analysis, calculated for C 20 H 24 Si2: C 74.93 H 7.55; found C 74.65 H 7.41.

[0049] (Synthesis Example 5) Synthesis of Compound A6 1,5-Dibromonaphthalene (0.80 g, 2.8 mmol), bis(triphenylphosphine)palladium(II) dichloride (44 mg, 0.063 mmol), copper iodide (33 mg, 0.17 mmol), and triphenylphosphine (45 mg, 0.17 mmol) were dissolved in tetrahydrofuran (28 mL) under a nitrogen atmosphere, followed by the addition of diisopropylamine (29 mL). The solution was heated to 100 °C, and triisopropylsilylacetylene (1.1 g, 6.0 mmol) was added dropwise. After the reaction was complete, the tetrahydrofuran and diisopropylamine were removed by distillation under reduced pressure, and the residue was extracted with dichloromethane. The dichloromethane solution was dried over anhydrous sodium sulfate, and the dichloromethane was removed by distillation under reduced pressure. The resulting crude product was purified by silica gel column chromatography using n-hexane as a developing solvent and recrystallized from methanol. Through the above steps, the target compound A6 was obtained in an amount of 1.15 g and a yield of 83%. 1 H-NMR (400 MHz, CDCl3, TMS): δ 8.39-8.37 (2H), 7.76-7.74 (2H), 7.52-7.48 (2H), 1.20-1.18 (42H). Elemental analysis, calculated for C 32 H 48 Si2: C 78.61 H 9.90; found C 78.39 H 9.86.

[0050] Example 1 Preparation and Evaluation of Photon Upconversion Compositions Containing Compounds A1 and D1 [1] Preparation of a solution containing Compound A1 and Compound D1 In a glove box under an Ar atmosphere, Compound A1 and Compound D1 were dissolved in tetrahydrofuran to prepare a tetrahydrofuran solution (Composition 1), where the concentration of Compound A1 was 10 mM and the concentration of Compound D1 was 100 μM. In addition, a tetrahydrofuran solution of Compound A1 and Compound D1 (Composition 2) was prepared in the same manner except that the concentration of Compound D1 was changed to 300 μM.

[0051] The degassed composition 1 was irradiated with 445 nm excitation light and the emission spectrum was measured, and the results are shown in Figure 2. The multiple emission spectra shown in Figure 2 were obtained when the irradiation intensity of the excitation light was 0.030 mW / cm 2 ~5.8W / cm 2 The emission spectrum was measured by gradually changing the wavelength within the range of 1000 nm to 1500 nm. The emission peaks that appeared in the ultraviolet region of this emission spectrum were plotted on a double logarithmic graph in Figure 3, with the intensity at the maximum emission wavelength (peak intensity) on the vertical axis and the excitation light intensity on the horizontal axis. The emission spectrum of composition 2 was also measured under similar conditions using 445 nm excitation light, and the emission peak intensities observed in the ultraviolet region were plotted on a double logarithmic graph in Figure 3. In Figure 3, "100 μM" and "300 μM" are the concentrations of compound D1, and correspond to compositions 1 and 2, respectively. Furthermore, "1 sun" refers to the light intensity of 1.4 mW / cm2 contained in the 440-450 nm wavelength region of AM1.5 sunlight. 2 And "I th ” represents the threshold excitation intensity. As shown in Figure 2, a large emission peak was observed in the ultraviolet region of the emission spectrum of Composition 1. This emission peak appeared upon irradiation with excitation light at a wavelength at which Compound D1 exhibits strong absorption, and overlaps with the fluorescence peak of Compound A1. Therefore, it can be said that this emission peak is derived from fluorescent radiation (UC emission) from Compound A1 due to the UC emission mechanism shown in Figure 1. Furthermore, as shown in Figure 3, when the emission peak intensity observed in this ultraviolet region is plotted on the above-mentioned double logarithmic graph and fitted, a first line with a slope of 2, a second line with a slope of 1, and an inflection point at the intersection of the first and second lines are obtained. Here, the region corresponding to the first line indicates a state where the number of triplet excitons is small due to low excitation light intensity, and the probability of triplet-triplet annihilation is low compared to the probability of triplet exciton non-radiative deactivation. In other words, the first line reflects a state where the number of triplet excitons undergoing triplet-triplet annihilation is smaller than the number of triplet excitons undergoing non-radiative deactivation. On the other hand, the inflection point reflects a state where the number of triplet excitons undergoing triplet-triplet annihilation is equal to the number of triplet excitons undergoing non-radiative deactivation, and further, the excitation light intensity at the inflection point (threshold excitation intensity I th ), photon upconversion luminescence due to triplet-triplet annihilation becomes dominant over non-radiative deactivation of triplet excitons. In other words, at the threshold excitation intensity I th The smaller the value of is, the more efficient UC emission occurs at a lower excitation intensity. th is 2.3mW / cm 2 and the inflection point I of composition 2 th is 1.1mW / cm 2 This shows that the photon upconversion composition of the present invention can maintain its I even when exposed to weak light such as sunlight or indoor lighting. th It was found that high UC efficiency could be achieved beyond this.

[0052] Next, the degassed composition 1 was irradiated with simulated sunlight at AM1.5 using a solar simulator equipped with a 450 nm long-pass filter, and the emission spectrum was measured. The measurement results are shown in Figure 4. Furthermore, the emission spectrum was measured by irradiating composition 1 with light from a desktop LED light, and the results are shown in Figure 5. For comparison, a tetrahydrofuran solution in which only compound A1 was dissolved at a concentration of 10 mM (compound A1 solution) was also irradiated with simulated sunlight and LED light under the same conditions, and the emission spectrum was measured. The results are also shown in Figures 4 and 5. In this measurement, the irradiation intensity of the simulated sunlight irradiated on Composition 1 was 1.4 mW / cm at 445 nm ± 5 nm. 2 The irradiation intensity of the tabletop LED light is 1 mW / cm in the wavelength range below 500 nm. 2 The long-pass filter attached to the solar simulator was used to cut light in the short wavelength range, thereby preventing compound A1 from being directly excited by simulated sunlight. As shown in Figures 4 and 5, a large emission peak was observed in the ultraviolet region of the emission spectrum of Composition 1 when irradiated with both simulated sunlight and LED light. On the other hand, no emission peak in the ultraviolet region, as observed in Composition 1, was observed in the emission spectrum of the solution containing only Compound A1. These results indicate that the emission peak in the ultraviolet region observed in Composition 1 is photon upconversion emission due to triplet-triplet annihilation of Compound A1, utilizing the triplet excitation energy of Compound D1. This confirms that the photon upconversion composition of the present invention generates photon upconversion emission due to triplet-triplet annihilation even when irradiated with sunlight or indoor lighting such as a desktop LED lamp.

[0053] [2] Preparation of a film containing compound A1 and compound D1 Next, a film containing Compound A1 and Compound D1 was prepared as follows. (Preparation of Film 1) In a glove box under an Ar atmosphere, polystyrene, Compound A1, and Compound D1 were dissolved in chloroform to prepare a solution. Here, the amount of Compound A1 was 30 wt % relative to the total amount of the polymer, Compound A1, and Compound D1, and the ratio of Compound A1 to Compound D1 was Compound A1:Compound D1=100:1 (molar ratio). This solution was formed into a film on a glass substrate by a drop-cast method to form Film 1, and a glass substrate was placed on top of it, and the gap between the two glass substrates was filled with an epoxy adhesive (Araldite). R ) was used for sealing. This resulted in a sealed product having a glass substrate / film / glass substrate structure.

[0054] (Preparation of films 2 to 4) Films 2 to 4 were prepared in the same manner as Film 1, except that the polymers shown in Table 2 were used instead of polystyrene, and the compound A1 content (ratio to the total amount of polymer, compound A1, and compound D1) was 23 wt % for Films 2 and 3, and 7.6 wt % for Film 4. A glass substrate was placed on the film and the film was then coated with Araldite. R The sealed product was obtained by sealing with the above.

[0055] (Preparation of Film 5) Film 5 was prepared in the same manner as Film 1, except that a solution prepared by dissolving Compound A1 and Compound D1 in chloroform at a molar ratio of Compound A1:Compound D1=100:1 was used as the solution for film formation. A glass substrate was placed on the film and the film was then coated with Araldite. R The sealed product was obtained by sealing with the above.

[0056] (Preparation of Film 6) Under atmospheric conditions, a surfactant (Pluronic F127), Compound A1, and Compound D1 were dissolved in chloroform at a molar ratio of Pluronic F127:Compound A1:Compound D1 = 960:100:1. This solution was dried, and an aqueous solution of polyvinyl alcohol was added to the residue to prepare a liquid material. The proportion of Pluronic F127 was 11 wt% based on the total weight of Pluronic F127, Compound A1, Compound D1, polyvinyl alcohol, and Pluronic F127. Film 6 was produced by drop-casting this liquid material.

[0057] (Preparation of Film 7) Compounds A1 and D1 were dissolved in a surfactant (TX-100) under atmospheric pressure and mixed with an aqueous solution of polyvinyl alcohol to prepare a liquid material. The concentration of compound A1 in TX-100 was 10 mM, and the concentration of compound D1 in TX-100 was 100 μM. The proportion of TX-100 was 1 wt % relative to the total amount of compound A1, compound D1, polyvinyl alcohol, and TX-100. Film 7 was produced by drop-casting this liquid material.

[0058] [Table 2]

[0059] The structural formulae of the polymers used in films 1 to 4, 6, and 7 and the surfactants used in films 6 and 7 are shown below.

[0060] [ka]

[0061] The UC emission spectra of each film are shown in Figures 6 to 12. ex The wavelength indicated by indicates the wavelength of the excitation light irradiated. The excitation light intensity was 450 mW / cm 2 A 425 nm short-pass filter was used between the sample and the spectrometer. As shown in FIGS. 6 to 12, in the emission spectra of all of Films 1 to 7, an emission peak resulting from photon upconversion emission could be observed in the ultraviolet region. Among the polymers used in this example, polystyrene, poly(methyl methacrylate), and poly(N-isopropylacrylamide) have glass transition temperatures above room temperature and exhibit rigid properties. Therefore, in Films 1 to 3 using these polymers, molecular diffusion did not occur, and it is presumed that the transfer of excited triplet energy from Compound D1 to Compound A1 and the triplet-triplet annihilation of Compound A1 occurred via energy diffusion. On the other hand, the poly(butyl acrylate) used in Film 4 is a polymer with a glass transition temperature below room temperature and exhibits soft properties. Therefore, in Film 4, it is presumed that excited triplet energy transfer and triplet-triplet annihilation occurred not only through energy diffusion but also through molecular diffusion of Compounds A1 and D1. Film 5 does not contain a matrix material, and the donor compound is dispersed in the solid acceptor compound. Therefore, there is no molecular diffusion in Film 5, and it is thought that the transfer of excited triplet energy from Compound D1 to Compound A1 and the triplet-triplet annihilation of Compound A1 occur via energy diffusion. The polyvinyl alcohol used in films 6 and 7 is a polymer with a glass transition temperature above room temperature and oxygen barrier properties. In films 5 and 6, compounds A1 and D1 are dissolved in a soft liquid (surfactant) in the hard polyvinyl alcohol. Therefore, it is presumed that excited triplet energy transfer and triplet-triplet annihilation occurred not only through energy diffusion but also through molecular diffusion of compounds A1 and D1.

[0062] (Preparation of Film 8) In a glove box under an Ar atmosphere, Compound A1 and Compound D1 were dissolved in hexyl benzoate to prepare a solution. A microporous film (manufactured by 3M: a porous film formed from polypropylene and organic filler) was immersed in this solution to prepare a film impregnated with the solution of Compound A1 and Compound D1 (Film 8). The Compound A1 concentration in the solution was 10 mM, and the Compound D1 concentration was 100 μM. 15 μm-thick films made of ethylene-vinyl alcohol copolymer (EVOH film) were placed on the top and bottom of the prepared Film 8, and the periphery of Film 8 was sealed with a heat seal to obtain a sealed product with an EVOH film / Film 8 / EVOH film structure. The EVOH film used was Kuraray's "Eval" film (ethylene 32 mol%, grade: EF-F) and was used as an oxygen barrier film. The UC emission spectrum of the prepared film 8 is shown in Figure 13. The measurement was performed at an excitation light wavelength of λ exThe wavelength was set to 460 nm, and a 400 nm long wavelength cut filter was placed between the sample and the spectrometer. This long wavelength cut filter was also used in the measurements shown in Figures 14 and 17 below. The emission intensity of Film 8 was calculated by integrating the range of 350 to 400 nm of each UC emission spectrum, and was found to be 112.7 μW / cm before folding. 2 , and 211.0 μW / cm when folded in half 2 The myopia suppression effect of 360-400 nm ultraviolet light was 50 μW / cm 2 It is known that the above effects are exhibited, and from these measurement results, it was confirmed that the film of the present invention is effective in suppressing myopia.

[0063] (Production of Film 9) In a glove box under an Ar atmosphere, a mixture of Compound A1 and Compound D1 was heated to melt Compound A1, and a liquid material in which Compound D1 was dissolved in the molten Compound A1 was obtained. Here, the molar ratio of Compound A1 to Compound D1 (Compound A1:Compound D1) was 220:1. A microporous film (manufactured by 3M) was immersed in this liquid material to prepare a film (Film 9) impregnated with Compound A1 and Compound D1. Film 9 was sandwiched between two glass substrates, and the gap between them was filled with an epoxy adhesive (Araldite). R ) to obtain a sealed product having a structure of glass substrate / film 9 / glass substrate. For the prepared film 9, the excitation light intensity was 6.5 mW / cm 2 to 39.2 W / cm 2 The UC emission spectrum was measured using 445 nm excitation light at each wavelength, with the wavelength gradually changed between 1000 and 1000 nm. The results are shown in Figure 14. The threshold excitation intensity I of Film 9 was calculated from the excitation light intensity dependence of the UC emission intensity. th is 408.9mW / cm 2 This indicates that films produced by melting naphthalene compounds are also useful as photon upconversion materials.

[0064] Example 2 Preparation and Evaluation of Photon Upconversion Compositions Containing Compounds A2 and D2 In a glove box under an Ar atmosphere, Compound A2 and Compound D2 were dissolved in toluene to prepare a toluene solution (Composition 3), where the concentration of Compound A2 was 10 mM and the concentration of Compound D2 was 100 μM. Emission with a peak within 360 to 400 nm was observed, confirming photon upconversion.

[0065] Example 3 Preparation and Evaluation of Photon Upconversion Compositions Containing Compounds A3 and D1 In a glove box under an Ar atmosphere, Compound A3 and Compound D1 were dissolved in tetrahydrofuran to prepare a tetrahydrofuran solution (Composition 4), where the concentration of Compound A3 was 10 mM and the concentration of Compound D1 was 100 μM. For composition 4, the excitation light intensity was 0.11 mW / cm 2 to 7.4 W / cm 2 The UC emission spectrum was measured using 445 nm excitation light at a threshold excitation intensity of 1.0 nm for composition 4. The results are shown in Figure 15. th is 7.0mW / cm 2 , UC efficiency η UC is 7.4W / cm 2 The rate was 18.8%. Furthermore, the time dependence of UC luminescence after the irradiation of excitation light was measured for Composition 4, and the results are shown in Figure 16. As shown in Figure 16, the UC luminescence of Composition 4 only slightly attenuated even after 30 minutes had passed.

[0066] Example 4 Preparation and Evaluation of Photon Upconversion Compositions Containing Compounds A4 and D1 A tetrahydrofuran solution of Compound A4 and Compound D1 (Composition 5) was prepared in the same manner as in Example 3, except that Compound A4 was used instead of Compound A3. For composition 5, the excitation light intensity was 0.12 mW / cm 2 to 37.8 W / cm 2 The UC emission spectrum was measured using 445 nm excitation light at each wavelength, and the results are shown in Figure 17. this 27.5mW / cm 2 , UC efficiency η UC is 3.1W / cm 2 The rate was 13.0%. Furthermore, when the fluorescence quantum yield of compound A4 was measured for its solution and crystals, the values ​​were nearly identical. While the fluorescence quantum yield of ordinary fluorescent materials drops significantly when crystallized, the crystals exhibited a fluorescence quantum yield equivalent to that of the solution. This is thought to be due to the steric hindrance of the t-butyl groups in compound A4, which maintains an appropriate amount of space between the molecules of the crystals. This indicates that compound A4 can exhibit a high fluorescence quantum yield even at high concentrations when mixed with resins such as epoxy resin, polystyrene, and polymethyl methacrylate, making it effective as a UV-emitting source for myopia prevention glasses and resin films.

[0067] Example 5 Preparation and Evaluation of Photon Upconversion Compositions Containing Compounds A5 and D1 A tetrahydrofuran solution of Compound A5 and Compound D1 (Composition 6) was prepared in the same manner as in Example 3, except that Compound A5 was used instead of Compound A3. For composition 6, the excitation light intensity was 0.66 mW / cm 2 to 119W / cm 2 The UC emission spectrum was measured using 445 nm excitation light at each wavelength, and the results are shown in Figure 18. th is 181.5mW / cm 2 , UC efficiency η UC is 119W / cm 2 The rate was 14.2%.

[0068] Example 6 Preparation and Evaluation of Photon Upconversion Compositions Containing Compounds A6 and D1 A tetrahydrofuran solution of Compound A6 and Compound D1 (Composition 7) was prepared in the same manner as in Example 3, except that Compound A6 was used instead of Compound A3. For composition 7, the excitation light intensity was 4.1 mW / cm 2 to 104W / cm 2The UC emission spectrum was measured using 445 nm excitation light at each wavelength, and the results are shown in Figure 19. th is 511mW / cm 2 , UC efficiency η UC is 66.7W / cm 2 The rate was 11.3%.

[0069] Furthermore, when films formed from Films 1 to 9 and Compositions 3 to 7 were attached to eyeglass lenses and glass products and their emission spectra were measured, an emission peak was detected in the range of 360 to 400 nm in all cases, confirming that the films of the present invention exhibit a photon upconversion effect even in actual products. [Industrial Applicability]

[0070] The photon upconversion composition of the present invention can efficiently convert excitation light into ultraviolet light at a lower excitation light intensity, thereby enabling efficient generation of ultraviolet light even from weak light such as sunlight or indoor lighting. Therefore, use of the photon upconversion composition of the present invention can greatly contribute to improving the efficiency of solar cell devices, including photocatalysts. Therefore, the present invention has high industrial applicability.

Claims

1. a naphthalene compound substituted with a substituted or unsubstituted alkynyl group, The substituted or unsubstituted alkynyl group is an alkynyl group substituted with a substituent selected from the group consisting of a group represented by the following general formula (1a), a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted aromatic ring group, and a substituted or unsubstituted heteroaromatic ring group, or has a structure represented by the following general formula (2a): A photon upconversion composition that exhibits photon upconversion luminescence derived from the naphthalene compound. 【Chemistry 1】 [In general formula (1a), R １ , R ２ and R ３ Each independently represents a substituted or unsubstituted alkyl group, and * represents the bonding position to the alkynyl group. In general formula (2a), R １１ , R １２ and R １３ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group; R １１ , R １２ and R １３ At least one of the groups is a substituted or unsubstituted alkyl group. ** indicates the bonding position to the naphthalene ring.]

2. 2. The photon upconversion composition of claim 1, wherein the naphthalene compound has an alkynyl group substituted with a group represented by general formula (1a).

3. The photon upconversion composition according to claim 1 or 2, wherein the naphthalene compound has a substituted or unsubstituted phenyl group.

4. 4. The photon upconversion composition according to claim 1, wherein the naphthalene compound has 2 to 4 of the substituted or unsubstituted alkynyl groups.

5. The photon upconversion composition of any one of claims 1 to 4, wherein the naphthalene compound is a 1,4-disubstituted naphthalene.

6. 2. The photon upconversion composition according to claim 1, wherein the naphthalene compound has a structure represented by the following general formula (1): 【Chemistry 2】 [In general formula (1), R １ , R ２ and R ３ each independently represents a substituted or unsubstituted alkyl group, X represents a group consisting of a combination of one or more groups selected from the group consisting of an alkynyl group, an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom; m is an integer from 1 to 8, n is an integer from 0 to 7, m+n is an integer from 1 to 8.

7. The photon upconversion composition according to claim 6 , wherein n in general formula (1) is 1 or more.

8. 2. The photon upconversion composition according to claim 1, wherein the naphthalene compound has a structure represented by the following general formula (2): 【Transformation 3】 [In the general formula (2), R １１ , R １２ and R １３ each independently represents a hydrogen atom or a substituted or unsubstituted alkyl group; R １１ , R １２ and R １３ at least one of is a substituted or unsubstituted alkyl group, X １ represents a group consisting of a combination of one or more groups selected from the group consisting of an alkynyl group, an alkenyl group, an alkyl group, an aromatic ring group, a heteroaromatic ring group, an alkoxy group, a carboxyl group, a cyano group, and a halogen atom; m1 is an integer from 1 to 8, n1 is an integer from 0 to 7, m1+n1 is an integer from 1 to 8.]

9. The photon upconversion composition according to claim 8 , wherein n1 in general formula (2) is 1 or more.

10. A film comprising the photon upconversion composition of any one of claims 1 to 9.

11. A myopia-suppressing transparent product comprising the photon upconversion composition of any one of claims 1 to 9 or the film of claim 10.

12. A method for converting visible light into ultraviolet light by irradiating the photon upconversion composition according to any one of claims 1 to 9 or the film according to claim 10 with visible light.

13. 13. The method of claim 12, wherein said ultraviolet light emission is found in the range of 360 to 400 nm.

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