A blue light-emitting composition and an organic electroluminescent device containing the same

Abstract

The present invention discloses a blue light-emitting composition and an organic electroluminescent device containing the same. The blue light-emitting composition comprises a host material having a general structural formula as shown in Formula I, and a guest material having a general structural formula as shown in Formula II. By using the blue light-emitting composition provided in the present invention, the effects of improving the orientation of the organic light-emitting material, increasing the life span, and reducing quenching can be achieved; at the same time, the organic electroluminescent device prepared by using the blue light-emitting composition of the present invention has good performance in external quantum efficiency, life span, and driving voltage.

Description

Technical Field

[0001] The invention belongs to the technical field of OLED, and specifically comprises a blue light-emitting composition and an organic electroluminescent device comprising the same. Background Art

[0002] In recent years, optoelectronic devices based on organic materials have become increasingly popular. Examples of such organic optoelectronic devices include organic light-emitting diodes (OLEDs), organic field effect transistors, organic photovoltaic cells, organic sensors, etc. Among them, OLED has developed particularly rapidly and has achieved commercial success in the field of information display. OLED can provide highly saturated red, green, and blue colors. Full-color display devices made of OLED do not require additional backlight sources and have the advantages of brilliant colors, short response time, wide color gamut, and high contrast.

[0003] In OLED devices, holes are injected from the anode and electrons are injected from the cathode. The two carriers are transmitted through the transport layer and then in the main material of the light-emitting layer. When the holes and electrons are balanced, they recombine to form excitons. The recombination area is called the recombination zone. Since the transmission rate of holes is much greater than that of electrons, the recombination zone of carriers in the light-emitting layer will vary due to differences in the carrier balance ability of the main material. There are a large number of excitons and carriers in the recombination zone. The narrower the recombination zone, the more frequent the host-guest energy transfer in the recombination zone, the higher the efficiency but the shorter the lifespan. Therefore, the difference in carrier balance will affect the device performance to a certain extent, restricting the reduction in voltage and the increase in lifespan.

[0004] OLED blue light-emitting systems are mostly doping systems, in which the main material is responsible for carrier transport and recombination to form excitons, and transfers the exciton energy to the doping material. The doping material emits light in the target wavelength range after receiving the energy transferred by the main material. Sometimes, sensitizers are introduced to improve the energy transfer efficiency between the host and the guest. The energy transfer efficiency between different host and guest materials is different. When the energy transfer between the host and the guest is poor, the device performance is reduced. In addition, the energy transfer between the host and the guest is also affected by the interaction between the host and the guest.

[0005] Boron nitrogen materials are currently the most commonly used blue light doping materials (Blue Dopant BD). Due to their MR-TADF (multiple resonance-thermally activated delayed fluorescence) effect, they exhibit narrow-band spectrum and high PLQY characteristics. However, while using long-lived triplet excitons to improve the exciton utilization rate, the material itself is planar, which makes the concentration quenching phenomenon significant. And common short-chain alkyl groups will weaken the orientation of the material itself. The lowest optical transition of organic light-emitting materials usually occurs on π electrons, which is manifested as π-π*. The side chain groups usually use aromatic groups with conjugated π bond structures. The introduction of conjugated groups often increases the HOMO energy level of the material, decreases the LUMO energy level, and narrows the energy gap, which causes the emission spectrum to red shift. In addition, the different substitution sites of organic light-emitting materials will also affect the luminescence due to the steric hindrance changes. For example, the introduction of large steric hindrance fragments into the side chain of blue light guest (BD) materials usually causes the emission spectrum to blue shift. The situation is similar for blue light host (BH) materials. When the type, number, and substitution site of the substitution groups on the anthracene ring change, it will affect the emission spectrum of the BH material. Therefore, when the BH or BD structure is modified and adjusted separately, the spectral changes of the two materials after modification are likely to be inconsistent. For example, when the emission spectrum of the BH material is at the bluer 400nm, and the absorption spectrum of the BD material is at the redder 430nm, the luminescence spectra of the guest and host materials cannot overlap well, resulting in poor energy transfer between the host and the guest.

[0006] Therefore, it is necessary to improve the performance of organic light-emitting devices based on the combination of host and guest materials and the simultaneous improvement of the properties of BD or BH materials. Summary of the invention

[0007] In view of the above problems existing in the prior art, the present invention provides a blue light-emitting composition and an organic electroluminescent device comprising the same.

[0008] To achieve the above objectives, the technical solutions adopted by the present invention include:

[0009] In a first aspect of the present invention, a blue light-emitting composition is provided, wherein the blue light-emitting composition comprises a host material having a general structural formula as shown in Formula I, and a guest material having a general structural formula as shown in Formula II:

[0010]

[0011] In Formula I,

[0012] Ar1 represents a substituted or unsubstituted phenyl group, naphthyl group or biphenyl group; L1 represents a single bond or a phenylene group;

[0013] The Ar2 is selected from any one of the structures shown in Formula A-1 to Formula A-4:

[0014]

[0015] The R 11 To R 14 , R 21 , R 22 , R 31 To R 34 , R 41 To R 44 Any one of which is bonded to L1 of the formula Ⅰ;

[0016] The R 11 To R 14 , R 21 , R 22 , R 31 To R 34 Each is independently selected from any one of hydrogen, deuterium, an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, and an aryl group having 6 to 30 carbon atoms, wherein adjacent groups may be bonded to each other through a linking group or a single bond to form an aromatic ring or a condensed ring;

[0017] When the R 11 To R 14 , R 21 , R 22 When any one of the following is selected from deuterium, the R 31 To R 34 are not selected from deuterium; when the R 11 To R 14 With R 21 , R 22 When neither is selected from deuterium, the R 31 To R 34 At least one of them is selected from deuterium, and when the R 11 To R 14 , R 21 , R 22 , R 31 To R 34 When any one of is selected from deuterium, all hydrogen atoms in the same benzene ring are replaced by deuterium;

[0018] The R 41 To R 44 , R 51 To R 54 Any one selected from hydrogen, deuterium, an aryl group having 6 to 10 carbon atoms, and a condensed ring aryl group having 10 to 15 carbon atoms;

[0019] When the R 41 To R 44 When any one of the following is selected from deuterium, the R 51 To R 54 are not selected from deuterium; when the R 41 To R 44When neither is selected from deuterium, the R 51 To R 54 At least one of them is selected from deuterium, and when the R 41 To R 44 , R 51 To R 54 When any one of is selected from deuterium, all hydrogen atoms in the same benzene ring are replaced by deuterium;

[0020] In formula II,

[0021] Ring A represents a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; L2 represents a single bond;

[0022] R1, R2, R3, and R5 each independently represent any one of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 30 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 60 carbon atoms, substituted or unsubstituted heteroaryl having 5 to 60 carbon atoms, substituted or unsubstituted condensed ring aryl having 5 to 60 carbon atoms, substituted or unsubstituted heterocondensed ring aryl having 5 to 60 carbon atoms, and substituted or unsubstituted amine; two or more R1, R2, R3, and R5 can each be connected to form a ring structure; preferably, two adjacent R1, R2, R3, or R5 can each be connected to form a ring structure, and the ring structure can be a four-membered ring, a five-membered ring, a six-membered ring, or a seven-membered ring, preferably a five-membered ring or a six-membered ring;

[0023] R4 represents any one of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 60 carbon atoms, substituted or unsubstituted heteroaryl having 5 to 60 carbon atoms, substituted or unsubstituted condensed ring aryl having 5 to 60 carbon atoms, substituted or unsubstituted heterocondensed ring aryl having 5 to 60 carbon atoms, and substituted or unsubstituted amine;

[0024] m, n, q each independently represent 0, 1, 2, 3 or 4; when m is 2, 3 or 4, R1 may be the same or different; when n is 2, 3 or 4, R2 may be the same or different; when q is 2, 3 or 4, R5 may be the same or different;

[0025] p represents 0, 1, 2, 3, 4 or 5; when p is 2, 3, 4 or 5, R3 may be the same or different;

[0026] r represents 0 or 1;

[0027] The substituents in the ring A, R1, R2, R3, R4, and R5 may be the same or different, and are independently selected from deuterium, halogen, cyano, alkyl having 1 to 10 carbon atoms, aryl having 6 to 60 carbon atoms, heteroaryl having 5 to 60 carbon atoms, condensed aromatic having 5 to 60 carbon atoms, cycloalkyl having 3 to 30 carbon atoms, and amine, wherein two or more substituents may be connected to form an aliphatic ring, an aromatic ring, or a condensed ring;

[0028] The hydrogen atoms on the compounds of formula II may be independently replaced by deuterium atoms.

[0029] Furthermore, the formula A-1 is selected from one of the structures shown in the following formulas A-111 to A-114:

[0030]

[0031]

[0032] The formula A-2 is selected from one of the structures shown in the following formulas A-211 to A-214:

[0033]

[0034] The formula A-3 is selected from one of the structures shown in the following formulas A-311 to A-314:

[0035]

[0036] Wherein, any one of the structures represented by Formula A-111 to Formula A-314 can be bonded to L1 of Formula I; and Formula A-4 is selected from one of the structures represented by the following Formula A-411 to Formula A-470:

[0037]

[0038]

[0039]

[0040]

[0041]

[0042] Wherein, * represents the bonding site with L1 of the formula I.

[0043] Furthermore, the compound represented by formula II is selected from formula II-1 or formula II-2,

[0044]

[0045] in,

[0046] Ring A represents a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms;

[0047] R1, R2, R3, and R5 each independently represent any one of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 30 carbon atoms, substituted or unsubstituted alkenyl having 2 to 30 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 60 carbon atoms, substituted or unsubstituted heteroaryl having 5 to 60 carbon atoms, substituted or unsubstituted condensed aromatic group having 5 to 60 carbon atoms, substituted or unsubstituted heterocondensed aromatic group having 5 to 60 carbon atoms, and substituted or unsubstituted amine; two or more R1, R2, R3, and R5 may each be connected to form a ring structure;

[0048] R4 represents any one of hydrogen, deuterium, halogen, substituted or unsubstituted alkyl having 1 to 30 carbon atoms, substituted or unsubstituted alkoxy having 1 to 30 carbon atoms, substituted or unsubstituted cycloalkyl having 3 to 30 carbon atoms, substituted or unsubstituted aryl having 6 to 60 carbon atoms, substituted or unsubstituted heteroaryl having 5 to 60 carbon atoms, substituted or unsubstituted condensed ring aryl having 5 to 60 carbon atoms, substituted or unsubstituted heterocondensed ring aryl having 5 to 60 carbon atoms, and substituted or unsubstituted amine;

[0049] m, n, q each independently represent 0, 1, 2, 3 or 4; when m is 2, 3 or 4, R1 may be the same or different; when n is 2, 3 or 4, R2 may be the same or different; when q is 2, 3 or 4, R5 may be the same or different;

[0050] p represents 0, 1, 2, 3, 4 or 5; when p is 2, 3, 4 or 5, R3 may be the same or different;

[0051] The substituents in the ring A, R1, R2, R3, R4, and R5 may be the same or different, and are independently selected from deuterium, halogen, cyano, alkyl having 1 to 10 carbon atoms, aryl having 6 to 60 carbon atoms, heteroaryl having 5 to 60 carbon atoms, condensed aromatic having 5 to 60 carbon atoms, cycloalkyl having 3 to 30 carbon atoms, and amine, wherein two or more substituents may be connected to form an aliphatic ring, an aromatic ring, or a condensed ring;

[0052] The hydrogen atoms on the compounds of formula II-1 or II-2 may be independently replaced by deuterium.

[0053] Furthermore, the cycloalkyl group is a cyclohexyl group or a cyclopentyl group.

[0054] Further, the R1, R2, R3, and R5 each independently represent hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, and two or more R1, R2, R3, and R5 may each be connected to form a ring structure;

[0055] R4 represents hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms;

[0056] The substituents in the ring A, R1, R2, R3, R4, and R5 may be the same or different, and are independently selected from deuterium and an alkyl group having 1 to 10 carbon atoms.

[0057] Furthermore, m, n, p, and q each independently represent 0, 1 or 2.

[0058] Furthermore, the ring A is represented by a cyclohexyl group or a cyclopentyl group.

[0059] Furthermore, the compound represented by formula I is selected from any one of the following compounds:

[0060]

[0061]

[0062]

[0063]

[0064] Furthermore, the compound represented by formula II is selected from any one of the following compounds:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] In a second aspect of the present invention, an organic electroluminescent device is provided, comprising an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode sequentially arranged on a substrate; wherein the light-emitting layer comprises one or more blue light-emitting compositions as described above.

[0072] Furthermore, the light-emitting layer includes a main material and a doping material, wherein the main material includes one or more compounds with a general structural formula as shown in Formula I, and the doping material includes one or more compounds with a general structural formula as shown in Formula II.

[0073] Beneficial effects of the present invention:

[0074] In the blue luminescent composition of the present invention, the sites of the aryl substituents on the anthracene nucleus of the blue light host material (BH) and the boron nitrogen parent nucleus of the blue light guest material (BD) have been fixed. In particular, the substituents of the biphenyl on the two side chains on the boron nitrogen parent nucleus of the BD material are ortho-substituted on one side and para-substituted on the other side, which makes the absorption spectrum of the BD material only affected by the small molecule alkyl substituents, and the fluctuation range is controllable. In addition to the conventional condensed ring, BH only uses furan-containing fragments, and the luminescence spectrum is only slightly affected by the different connection sites of the furan fragments. Therefore, when the composition of the present invention is used, the PL spectrum of BH has a good overlap with the UV spectrum of BD, and the Foster energy transmission is better. In addition, the partially deuterated aryl furans on the host material, such as partially deuterated dibenzofurans and partially deuterated naphthylbenzofurans, interact with the cycloalkyl groups of the guest material. Since local deuteration and cycloalkyl groups respectively enhance the unevenness of the charge distribution of the furan fragment and the ortho-biphenyl side chain, the dipole-dipole interaction between the two parts is enhanced, and the exciton energy transfer is improved, so that the device performance using the composition of the present invention exceeds that of the device using the compounds of the present invention separately.

[0075] In addition, the host material provided in the present invention contains a specific deuterated furan fragment. On the one hand, the introduction of highly electronegative oxygen-containing heterocycles improves the carrier balance ability of the host material, is conducive to forming a narrow recombination zone, and improves the luminous efficiency of the material; on the other hand, the introduction of deuterium in a specific part makes the device life long without increasing the voltage, and can reduce energy loss. The guest material used in the present invention is a biphenyl steric hindering group containing a specific substitution position of a cycloalkyl substitution, and a boron nitrogen material of a benzothiophene fragment. The benzothiophene fragment can increase the boron nitrogen conjugated surface, reduce the triplet exciton energy, and reduce exciton quenching. The ortho-biphenyl steric hindering group containing a cycloalkyl on one side of the benzothiophene fragment can significantly increase the spatial steric hindrance of the boron nitrogen material. The cycloalkyl group has the effect of strengthening the dipole of the ortho-biphenyl group, can weaken the concentration quenching effect brought by the benzothiophene ring, and strengthen the interaction with the host material. The para-biphenyl group on the other side of the boron nitrogen mother core can greatly expand the molecular size of the material, increase the site of interaction with the host material, and improve the molecular orientation.

[0076] Therefore, by using the blue light-emitting composition provided in the present invention, the effects of improving the orientation of organic light-emitting materials, increasing lifespan, and reducing quenching can be achieved. The organic electroluminescent device prepared using the blue light-emitting composition of the present invention has good performance in external quantum efficiency, lifespan, and driving voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 is a schematic structural diagram of an organic electroluminescent device comprising an organic compound containing a heteroatom and a cycloalkyl group according to the present invention;

[0078] Figure 2 It is the UV-PL image of the host and guest materials in device embodiment 1;

[0079] Figure 3 This is the UV-PL image of the host and guest materials in device comparison example 7.

[0080] Description of the drawings: 1-substrate, 2-anode, 3-hole injection layer, 4-hole transport layer, 5-luminescence auxiliary layer, 6-luminescent layer, 7-hole blocking layer, 8-electron transport layer, 9-electron injection layer, 10-cathode. DETAILED DESCRIPTION

[0081] In order to more clearly understand the content of the present invention, it will be described in detail with reference to the drawings and embodiments.

[0082] The compounds of the present invention are suitable for use in light-emitting elements, display panels and electronic devices, and are particularly suitable for use in organic electroluminescent devices. The electronic device described in the present invention is a device comprising a layer of at least one organic compound, and the device may also comprise an inorganic material or a layer formed entirely of an inorganic material. The electronic device is preferably an organic electroluminescent device (OLED), an organic integrated circuit (O-IC), an organic field effect transistor (O-FET), an organic thin film transistor (O-TFT), an organic light-emitting transistor (O-LET), an organic solar cell (O-SC), an organic dye-sensitized solar cell (O-DSSC), an organic optical detector, an organic photoreceptor, an organic field quenching device (O-FQD), a light-emitting electrochemical cell (LEC), an organic laser diode (O-laser) and an organic plasma emission device. The electronic device is preferably an organic electroluminescent device (OLED). The structural schematic diagram of an exemplary organic electroluminescent device is shown in FIG. Figure 1 shown.

[0083] Experimental Section

[0084] In order to understand the content of the present invention more clearly, the polycyclic compound, the preparation method of the compound and the luminescent characteristics of the device will be explained in detail in conjunction with the examples. Various chemical reactions can be applied to the synthetic method of the compound of an embodiment of the present invention. However, it should be noted that the synthetic method of the compound of an embodiment of the present invention is not limited to the synthetic method described below. Unless otherwise indicated, the subsequent synthesis is carried out in anhydrous solvent under a protective gas atmosphere. Solvents and reagents can be purchased from conventional reagent suppliers.

[0085] Compound

[0086] Intermediate synthesis

[0087] Synthesis of key intermediate structures of main materials:

[0088]

[0089] In a 100 ml reaction bottle, add compound 3-1 (1.44 g, 10 mmol) and 14 ml D2O. Under argon atmosphere, add Pt / C (0.12 g, 0.06 mmol). Heat to 180°C, react for 12 h, cool to room temperature, filter out the catalyst, and distill under reduced pressure to obtain 3-k (1.07 g, 71%).

[0090] In a 250 ml reaction bottle, 3-k (1.51 g, 10 mmol), diisopropylamine (0.10 g, 1 mmol), 30 ml DCM were added, and NBS (2.13 g, 12 mmol) was slowly added. The temperature was raised to 40 ° C. and the reaction was carried out for 12 h. The temperature was lowered to room temperature, and the system was made weakly acidic with 1N hydrochloric acid solution. 20 ml of water was added, stirred, and allowed to stand for separation. The organic phase was taken, and the aqueous phase was extracted with 20 ml of dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and passed through a silica gel column to obtain 3-j (1.19 g, 52%).

[0091] In a 250 ml reaction bottle, 35 ml of toluene, potassium acetate (1.96 g, 20 mmol), 3-j (2.29 g, 10 mmol), boric acid (3.05 g, 12 mmol), PdCl2 (dppf) (0.07 g, 0.1 mmol) were added under nitrogen protection, the temperature was raised to reflux, the reaction was carried out for 8 h, the temperature was lowered to room temperature, 20 ml of water was added, the mixture was stirred, and the stratification was allowed to stand. The organic phase was taken, evaporated to dryness under reduced pressure, and passed through a silica gel column to obtain 3-i (1.96 g, 71%).

[0092] In a 250ml three-necked flask, 30ml of toluene, 15ml of ethanol and 15ml of water were added under nitrogen protection, and then compound 3-i (2.76g, 10mmol), compound 3-h (3.01g, 10mmol), potassium carbonate (4.15g, 30mmol) and tetrakistriphenylphosphine palladium (0.35g, 0.3mmol) were added, and the mixture was heated to 80°C for 12h, cooled to room temperature, 15ml of water was added, stirred, and allowed to stand for stratification. The organic phase was evaporated to dryness under reduced pressure and passed through a silica gel column to obtain the product 3-g (2.36g, 73%).

[0093] In a 250 ml reaction bottle, add 35 ml DMF, compound 3-g (3.23 g, 10 mmol), slowly add 60% NaH (1 g, 25 mmol), raise the temperature to 140 ° C, react for 8 hours, cool to room temperature, pour into ice water, filter, and pass through a silica gel column to obtain 3-f (1.27 g, 42%).

[0094] Referring to the method of Synthesis Example 3-i, 3-j was replaced by 3-f (3.03 g, 10 mmol) to obtain compound 3-e (2.42 g, 69%).

[0095] Referring to the method of synthesis example 3-g, 3-i was replaced by 3-e (3.50 g, 10 mmol), 3-h was replaced by 3-d (2.57 g, 10 mmol), and compound 3-c (2.88 g, 72%) was obtained.

[0096] In a 250 ml reaction bottle, add compound 3-c (4.01 g, 10 mmol), 50 ml of dichloromethane, and 1 ml of acetic acid, slowly add NBS (2.13 g, 12 mmol), react at room temperature overnight, add 50 ml of water, stir, separate the liquids, spin dry the organic phase, and recrystallize to obtain 3-a (3.79 g, 79%).

[0097] Synthesis of key intermediate structures of guest materials:

[0098]

[0099]

[0100] M (2.54 g, 10 mmol) and N (2.34 g, 10 mmol) were added to a mixture of toluene and water (toluene: water = 80 ml: 20 mL), and then potassium carbonate (1.65 g, 10 mmol) was added to the system under nitrogen protection to introduce 1,1'-bis(diphenylphosphino)ferrocenepalladium dichloride (73 mg, 0.1 mmol), and then the reaction system was heated to reflux and maintained for 16 hours, cooled to room temperature, quenched with ice water and separated, the organic phase was filtered and dried over anhydrous magnesium sulfate, the solvent was removed by rotation, and the crude product was purified by column chromatography. Finally, the product P was obtained: 3.09 g (yield: 85%), MS (m / z) (M+): 364.

[0101] Q (6.2 g, 0.025 mol), P (8.37 g, 0.023 mol) and sodium tert-butoxide (2.64 g, 0.03 mol) were added to toluene (200 mL), and then bis(dibenzylideneacetonepalladium) (0.23 g, 0.25 mmol) and SPhos (0.21 g, 0.5 mmol) were introduced under nitrogen protection. The reaction system was then heated to 110° C., refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was filtered and dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was purified by column chromatography to obtain product S: 9.14 g, yield: 75%, MS (m / z) (M+): 530.

[0102] T (6.73 g, 0.025 mol), S (12.19 g, 0.023 mol) and sodium tert-butoxide (2.64 g, 0.03 mol) were added to toluene (200 mL), and then bis(dibenzylideneacetonepalladium) (0.23 g, 0.25 mmol) and SPhos (0.21 g, 0.5 mmol) were introduced under nitrogen protection. The reaction system was then heated to 110° C., refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was filtered and dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was purified by column chromatography to obtain product U: 11.25 g, yield: 68%, MS (m / z) (M+): 719.

[0103] U (35.95 g, 0.05 mol), V (12.56 g, 0.045 mol) and sodium tert-butoxide (5.28 g, 0.055 mol) were added to toluene (200 mL), and then bis(dibenzylideneacetonepalladium) (0.46 g, 0.50 mmol) and tri-tert-butylphosphine (0.26 g, 1 mmol) were introduced under nitrogen protection. The reaction system was then heated to 110° C., refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was filtered and dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was purified by column chromatography to obtain product W: 30.27 g, yield: 70%, MS (m / z) (M+): 961.

[0104] X (6.68 g, 0.025 mol), W (22.10 g, 0.023 mol) and sodium tert-butoxide (2.64 g, 0.03 mol) were added to toluene (200 mL), and then bis(dibenzylideneacetonepalladium) (0.23 g, 0.25 mmol) and SPhos (0.21 g, 0.5 mmol) were introduced under nitrogen protection. The reaction system was then heated to 110° C., refluxed and maintained for 8 hours, cooled to room temperature, quenched with water and separated, the organic phase was filtered and dried over anhydrous sodium sulfate, the solvent was removed by rotation, and the crude product was purified by column chromatography to obtain product Y-1: 18.34 g, yield: 65%, MS (m / z) (M+): 1227.

[0105] After Y-1 is obtained through the above process, other intermediates can be easily obtained by a method similar to Y-1.

[0106] Synthesis Example 1

[0107]

[0108] In a 250 ml three-necked flask, under nitrogen protection, add 50 ml of toluene, 25 ml of ethanol, and 25 ml of water, then add compound X-02 (4.79 g; 10 mmol), compound Z-02 (1.72 g; 10 mmol), potassium carbonate (4.15 g, 30 mmol), tetrakistriphenylphosphine palladium (0.35 g, 0.3 mmol), heat to 80 ° C for 12 hours, cool to room temperature, filter, dissolve the filter cake in toluene and pass it through a chromatography column to remove the catalyst, and then recrystallize to obtain the product BH02: 4.3 g (yield: 82%), MS (m / z) (M+): 524.

[0109] Synthesis Example 2

[0110]

[0111] The method is similar to that of preparing BH02, except that X-03 (4.76 g; 10 mmol) and Z-03 (1.72 g; 10 mmol) replace X-02 and Z-02, and the final product BH03: 4.35 g (yield: 83%), MS (m / z) (M+): 524.

[0112] Synthesis Example 3

[0113]

[0114] The method is similar to that for preparing BH02, except that X-06 (4.76 g; 10 mmol) and Z-06 (1.72 g; 10 mmol) replace X-02 and Z-02, and the final product BH06 is 3.98 g (yield: 76%), MS (m / z) (M+): 524.

[0115] Synthesis Example 4

[0116]

[0117] The method is similar to that for preparing BH02, except that X-07 (4.79 g; 10 mmol) and Z-07 (1.22 g; 10 mmol) replace X-02 and Z-02, and the final product BH07: 3.96 g (yield: 83%), MS (m / z) (M+): 477.

[0118] Synthesis Example 5

[0119]

[0120] The method is similar to that for preparing BH02, except that X-11 (4.79 g; 10 mmol) and Z-11 (1.22 g; 10 mmol) replace X-02 and Z-02, and the final product BH11: 3.93 g (yield: 75%), MS (m / z) (M+): 524.

[0121] Synthesis Example 6

[0122]

[0123] The method is similar to that for preparing BH02, except that X-18 (4.76 g; 10 mmol) and Z-18 (1.72 g; 10 mmol) replace X-02 and Z-02, and the final product BH18: 4.14 g (yield: 79%), MS (m / z) (M+): 524.

[0124] Synthesis Example 7

[0125]

[0126] The method is similar to that for preparing BH02, except that X-22 (4.77 g; 10 mmol) and Z-22 (1.98 g; 10 mmol) replace X-02 and Z-02, and the final product BH22 is 4.24 g (yield: 77%), MS (m / z) (M+): 551.

[0127] Synthesis Example 8

[0128]

[0129] The method is similar to that for preparing BH02, except that X-36 (5.56 g; 10 mmol) and Z-36 (1.22 g; 10 mmol) replace X-02 and Z-02, and the final product BH36 is 4.48 g (yield: 81%), MS (m / z) (M+): 553.

[0130] Synthesis Example 9

[0131]

[0132] The method is similar to that for preparing BH02, except that X-70 (5.02 g; 10 mmol) and Z-70 (1.72 g; 10 mmol) replace X-02 and Z-02, and the final product BH70 is 4.29 g (yield: 78%), MS (m / z) (M+): 550.

[0133] Synthesis Example 10

[0134]

[0135] The method is similar to that for preparing BH02, except that X-76 (5.02 g; 10 mmol) and Z-76 (1.22 g; 10 mmol) replace X-02 and Z-02, and the final product BH76: 3.9 g (yield: 78%), MS (m / z) (M+): 500.

[0136] Synthesis Example 11

[0137]

[0138] The method is similar to that for preparing BH02, except that X-80 (5.02 g; 10 mmol) and Z-80 (1.72 g; 10 mmol) replace X-02 and Z-02, and the final product BH80: 4.18 g (yield: 76%), MS (m / z) (M+): 550.

[0139] Synthesis Example 12

[0140]

[0141] Y-1 (12.27 g; 10 mmol) was added to tert-butylbenzene (125 ml), then the temperature was lowered to 0°C under nitrogen protection, 12.4 ml (21 mmol) of 1.7 M tert-butyl lithium pentane solution was added, the temperature was raised to 60°C and stirred for 2 hours, then the temperature was lowered to 0°C, 2.0 ml (21 mmol) of boron tribromide was added and stirred for 0.5 h, the temperature was lowered to 0°C, 3.65 ml (21 mmol) of N, N-diisopropylethylamine was added, the temperature was raised to 60°C and stirred for 2 h, ice water was added to cool to room temperature, and the mixture was separated, the organic phase was filtered and dehydrated with anhydrous magnesium sulfate, the organic solvent was removed by rotation, and the crude product was purified by recrystallization from dichloromethane and n-heptane. The product BD01 was finally obtained: 1.16 g (yield: 10%), MS (m / z) (M+): 1156.

[0142] Synthesis Example 13

[0143]

[0144] The method is the same as Example 12, except that Y-4 (11.12 g; 10 mmol) replaces Y-1, and the final product BD04 is 1.04 g (yield: 10%), MS (m / z) (M+): 1041.

[0145] Synthesis Example 14

[0146]

[0147] The method is the same as Example 12, except that Y-5 (12.27 g; 10 mmol) replaces Y-1, and the final product BD05 is 1.04 g (yield: 9%), MS (m / z) (M+): 1156.

[0148] Synthesis Example 15

[0149]

[0150] The method is the same as Example 12, except that Y-37 (11.53 g; 10 mmol) replaces Y-1, and the final product BD37 is obtained: 0.65 g (yield: 6%), MS (m / z) (M+): 1081.

[0151] Synthesis Example 16

[0152]

[0153] The method is the same as Example 12, except that Y-52 (11.99 g; 10 mmol) replaces Y-1, and the final product BD52 is obtained: 0.9 g (yield: 8%), MS (m / z) (M+): 1128.

[0154] Synthesis Example 17

[0155]

[0156] The method is the same as Example 12, except that Y-61 (12.27 g; 10 mmol) replaces Y-1, and the final product BD61: 1.04 g (yield: 9%), MS (m / z) (M+): 1156.

[0157] Synthesis Example 18

[0158]

[0159] The method is the same as Example 12, except that Y-71 (11.26 g; 10 mmol) replaces Y-1, and the final product BD71 is obtained: 0.74 g (yield: 7%), MS (m / z) (M+): 1055.

[0160] Synthesis Example 19

[0161]

[0162] The method is the same as Example 12, except that Y-82 (12.37 g; 10 mmol) replaces Y-1, and the final product BD82 is obtained: 0.7 g (yield: 6%), MS (m / z) (M+): 1166.

[0163] Synthesis Example 20

[0164]

[0165] The method is the same as Example 12, except that Y-84 (11.99 g; 10 mmol) replaces Y-1, and the final product BD84 is obtained: 0.56 g (yield: 5%), MS (m / z) (M+): 1128.

[0166] Synthesis Example 21

[0167]

[0168] The method is the same as Example 12, except that Y-91 (12.11 g; 10 mmol) replaces Y-1, and the final product BD91 is obtained: 0.57 g (yield: 5%), MS (m / z) (M+): 1140.

[0169] Synthesis Example 22

[0170]

[0171] The method is the same as Example 12, except that Y-100 (10.82 g; 10 mmol) is used to replace Y-1, and the final product BD100 is obtained: 0.81 g (yield: 8%), MS (m / z) (M+): 1011.

[0172] Composition performance

[0173] The normalized PL spectrum of the test subject material and the normalized UV spectrum of the guest material are tested. The larger the overlap area between the two, the better the energy transfer between the subject and guest materials, and the more conducive to improving the luminous efficiency of the organic electroluminescent device. UV / PL spectrum test method: The sample to be tested is prepared into 1*10 -7 The photoluminescence spectrum of the host material sample was tested using a HORIBA Scientific fluorescence spectrometer, and the UV-visible absorption spectrum of the guest material was tested using a double-beam UV-visible spectrophotometer (model: TU 1901). The spectra were plotted in origin and the spectral overlap area (S) was calculated.

[0174] The carrier balance ability of the composition of the present invention is evaluated by calculating the hole-electron balance coefficient of the host and guest materials. The smaller the difference in balance coefficient between the host and guest materials, the more consistent the transport effect of the two on carriers is, which can reduce the situation of trapping carriers and excitons caused by doping, and is conducive to reducing the energy consumption of the device. Test method: Gaussian16 software is used to optimize the structure of the host and guest materials of the present invention by using the B3LYP / 631G (d) method, calculate the hole-electron reorganization energy and obtain the balance coefficient. The orientation of the molecular dipole moment in the light-emitting layer is measured by angle-dependent fluorescence spectroscopy, and the molecular orientation test system produced by Hamamatsu (HAMAMATSU) of Japan is used for measurement.

[0175] The composition of the present invention is co-evaporated to form an organic film (wherein the mass concentration ratio of the guest material doping is 3%, and the mass concentration ratio of the main material is 97%), and the performance of the composition of the present invention in terms of orientation is evaluated. Test method: Use 365nm ultraviolet light for excitation, measure the distribution of the fluorescence intensity of the organic film with the test angle, and measure its anisotropy factor α through optical fitting software. The smaller α is, the more horizontal photon components there are in the doping material of the organic film, and the higher the utilization rate of the radiant luminescence of the doping material. The angle-dependent fluorescence spectroscopy method is used to measure the orientation of the molecular dipole moment in the luminescent layer, and the molecular orientation test system produced by Hamamatsu (HAMAMATSU) of Japan is used for measurement.

[0176] The composition of the present invention was tested by the above method. For comparison, DBBH01-03 can be used as the main material and DBBD01-03 can be used as the guest material. The test results of the composition performance are shown in Table 1 below:

[0177]

[0178]

[0179] Table 1 Composition performance test results

[0180]

[0181]

[0182]

[0183] It can be seen from the test results shown in the above table that the spectral overlap area between the host and guest materials of the composition of the present invention is larger than that of the comparative example, indicating that the energy transmission between the host and guest materials of the composition of the present invention is better. Secondly, it can be seen that the carrier balance coefficient between the host and guest materials of the composition of the present invention is relatively close, which makes the light-emitting layer of the composition of the present invention in the device have fewer traps, thereby helping to reduce energy loss and lower voltage. In addition, the anisotropy factor of the composition of the present invention is significantly smaller than that of the comparative example, indicating that there is a certain interaction between the guest material of the present invention and the host material, so that the guest material has a better orientation level when the composition of the present invention is used.

[0184] Fabrication and characterization of OLEDs

[0185] Device Embodiment

[0186] The organic electroluminescent device provided by the present invention comprises an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode which are sequentially arranged on a substrate;

[0187] Furthermore, the hole transport region includes a hole injection layer, a hole transport layer and a light-emitting auxiliary layer; and the electron transport region includes an electron transport layer and an electron injection layer.

[0188] Furthermore, the light-emitting layer is composed of a host material and a guest material, and the host material of the light-emitting layer can be composed of one molecular material or multiple molecular materials.

[0189] The composition of the present invention can be used for the light-emitting layer of the above-mentioned organic electroluminescent device.

[0190] The anode in the embodiment adopts anode materials commonly used in the art, such as ITO, Ag or their multilayer structures. The hole injection layer adopts hole injection materials commonly used in the art, and F4TCNQ, HATCN, NDP-9, etc. are added for doping. The hole transport layer adopts hole transport materials commonly used in the art. The light-emitting layer adopts the host and guest material composition provided by the present invention. The electron transport layer adopts electron transport materials commonly used in the art. The electron injection layer adopts electron injection materials commonly used in the art, such as Liq, LiF, Yb, etc. The cathode adopts materials commonly used in the art, such as metal Al, Ag or metal mixtures (Ag-doped Mg, Ag-doped Ca, etc.).

[0191] The electrode preparation method and the deposition method of each functional layer in this embodiment are conventional methods in the art, such as vacuum thermal evaporation or inkjet printing, etc., which will not be described in detail here. Only some process details and test methods in the preparation process are supplemented as follows:

[0192] Device Example 1

[0193] The present embodiment provides a blue light organic electroluminescent device, and the preparation method thereof is as follows: first, on the ITO layer (anode) formed on the substrate, HTL-01 and p-dopant-01 (the mass ratio of HTL-01 to p-dopant-01 is 97:3) are vacuum deposited with a thickness of 10 nm to form a hole injection layer; secondly, on the hole injection layer, HTL-01 is vacuum deposited with a thickness of 120 nm to form a hole transport layer; and secondly, on the hole transport layer, B is vacuum deposited with a thickness of 5 nm. prime-01 forms a luminescent auxiliary layer; again, on the above-mentioned luminescent auxiliary layer, a composition of BH02 and BD01 is vacuum deposited with a thickness of 20nm to form a luminescent layer, wherein BH02 serves as a host and BD01 serves as a guest, and the mass ratio of the host to the guest is 98:2; then, on the above-mentioned luminescent layer, HBL-01 is vacuum deposited with a thickness of 5nm to form a hole blocking layer; a mixture of ET-01 and Liq (mass ratio 1:1) is vacuum deposited with a thickness of 30nm to form an electron transport layer; then, on the above-mentioned electron transport layer, LiF is deposited with a thickness of 0.2nm to form an electron injection layer, and finally, on the above-mentioned electron injection layer, aluminum (Al) is deposited with a thickness of 150nm to form a cathode, and a blue light organic electroluminescent device is prepared.

[0194] Except for the host and guest materials of the light-emitting layer, the molecular structures of the materials in the remaining layers are as follows:

[0195]

[0196] The above method is used to prepare organic electroluminescent devices from the compositions described in other embodiments in Table 1, and blue light organic electroluminescent device embodiments 2 to 94 are prepared by replacing the composition of BH02 and BD01 in device embodiment 1 with the host and guest material compositions shown in the embodiments in Table 1.

[0197] Device Comparison

[0198] The composition described in the comparative example in Table 1 was prepared into an organic electroluminescent device by the above method, and the composition of BH02 and BD01 in device example 1 was replaced by the host and guest material compositions shown in the comparative example in Table 1 to prepare blue light organic electroluminescent device comparative examples 1 to 7.

[0199] The OLED devices described above were tested by standard methods. For this purpose, at J = 10 mA / cm 2 The driving voltage, brightness, electroluminescent current efficiency (measured in cd / A) and external quantum efficiency (EQE, measured in percentage) of the organic electroluminescent device are determined at a current density of , which is calculated from a current / voltage / luminescent density characteristic line (IVL characteristic line) showing Lambertian emission characteristics as a function of luminous density. The lifetime LT is defined as the time after which the brightness decreases from the initial luminous brightness L0 to a specific proportion L1 when operating at a constant current J; for example, J = 50 mA / cm 2 The expression L1 = 90% means that at 50 mA / cm 2 When working under LT, the luminance drops to 90% of its initial value L0 after time LT. Similarly, J = 20 mA / cm 2 , L1 = 80% means at 20mA / cm 2 When working under LT, the luminous brightness drops to 80% of its initial value L0 after time LT.

[0200] The data of various OLED devices are summarized in Table 2. Various parameters of the embodiments are compared with those of the comparative examples, and the performance data of various OLED devices are shown.

[0201] The test instruments and methods for testing the performance of the OLED devices in the above embodiments and comparative examples are as follows:

[0202] Brightness was tested using a spectral scanner PhotoResearch PR-635;

[0203] Current density and lighting voltage: tested using a digital source meter Keithley 2400;

[0204] Life test: Use LT-96ch life test device.

[0205] The performance test results of the above devices are listed in Table 2.

[0206] Table 2 Device performance test results

[0207]

[0208]

[0209]

[0210] From the device performance test results in Table 2 above, it can be seen that the voltage of the organic material of the present invention is reduced when used in an organic electroluminescent device, and the efficiency and life are significantly improved compared with the control example. This is because the present invention reasonably selects the host material and the guest material, fully utilizes the interaction between the host and the guest, and the combination of different subject materials, so that the final device of the present invention shows significant advantages.

[0211] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A blue light-emitting composition, characterized in that: The blue light-emitting composition comprises a host material having a general structural formula as shown in Formula I, and a guest material having a general structural formula as shown in Formula II-1: Ⅰ、 Ⅱ-1； In Formula I, L1 represents a single bond, and Ar1 represents a phenyl group, a naphthyl group, or a biphenyl group; or L1 represents a phenylene group, and Ar1 represents a phenyl group; The Ar2 is selected from any one of the following structures: A-111、 A-112、 A-113、 A-114; A-211、 A-212、 A-213、 A-214; In formula II-1, Ring A represents a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; The R1, R2, R3, and R5 each independently represent hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, and two or more R1, R2, R3, and R5 may each be connected to form a ring structure; R4 represents hydrogen, deuterium, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms; m, n, q each independently represent 0, 1, 2, 3 or 4; when m is 2, 3 or 4, R1 may be the same or different; when n is 2, 3 or 4, R2 may be the same or different; when q is 2, 3 or 4, R5 may be the same or different; p represents 0, 1, 2, 3, 4 or 5; when p is 2, 3, 4 or 5, R3 may be the same or different; The cycloalkyl group is a cyclohexyl group or a cyclopentyl group; The substituents in the ring A, R1, R2, R3, R4, and R5 may be the same or different, and are independently selected from deuterium and an alkyl group having 1 to 10 carbon atoms; The hydrogen atoms on the compound represented by formula II-1 may be independently replaced by deuterium atoms.

2. The blue light-emitting composition according to claim 1, characterized in that: The m, n, p, and q each independently represent 0, 1, or 2.

3. The blue light-emitting composition according to claim 1, characterized in that: The compound represented by formula I is selected from any one of the following compounds: 。 4. The blue light-emitting composition according to claim 1, characterized in that: The compound represented by formula II-1 is selected from any one of the following compounds: 。 5. An organic electroluminescent device, characterized in that: The invention comprises an anode, a hole transport region, a light-emitting layer, an electron transport region, and a cathode which are sequentially arranged on a substrate; wherein the light-emitting layer comprises one or more blue light-emitting compositions according to any one of claims 1 to 4; The light-emitting layer includes a main material and a doping material, wherein the main material includes one or more compounds with a general structural formula as shown in Formula I, and the doping material includes one or more compounds with a general structural formula as shown in Formula II-1.

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