CN111592464A - Organic Compounds Containing Spirobifluorene Structure and Their Applications - Google Patents

Abstract

The invention discloses an organic compound with a spirobifluorene structure containing a diarylamine substituted group, which has the structure shown in formula (1). The compound has a non-planar spatial structure, high glass transition temperature, suitable HOMO and LUMO energy levels, and high Eg, and can be sublimated without decomposition and residues, which can effectively improve OLED devices It is suitable for phosphorescent and fluorescent OLED devices, especially when using the compound as hole injection material and/or hole transport material.

Description

Organic Compounds Containing Spirobifluorene Structure and Their Applications

technical field

The invention belongs to the technical field of organic electroluminescence (organic EL, also known as OLED), and in particular relates to an organic compound containing a spirobifluorene structure that can be used in OLED devices, and its application in OLED devices, and also relates to an organic compound containing a spirobifluorene structure that can be used in OLED devices. The OLED device of the organic compound.

Background technique

OLED devices have the advantages of self-luminescence, high contrast, good color saturation, wide viewing angle, fast response speed and rollability, etc., and are currently recognized as the most promising new generation display technology. Inorganic optoelectronic materials are bulk materials composed of hard metals, metalloids, and semiconductor elements. They are one piece and cannot be bent. Different from this, OLED materials are formed by stacking organic molecules to form a continuous film, and the thickness of each film is less than 0.0001. Centimeter (ie sub-micron level), soft and bendable, can be freely used in the Internet of Things, wearable devices, military aircraft, etc. If applied to white light illumination, OLED also has the advantage of energy saving, so it is a popular member of optoelectronic materials.

The OLED photoelectric functional material film layer that constitutes the OLED device includes at least two or more layers of structure. The industrially applied OLED device usually includes a hole injection layer (HIL), a hole transport layer (HTL), an electron blocking layer (EBL), and a light emitting layer. (EML), hole blocking layer (HBL), electron transport layer (ETL), electron injection layer (EIL) and other film layers, which means that the optoelectronic functional materials of OLED devices at least include hole injection materials, hole transport materials materials, luminescent materials, electron transport materials, etc. The material types and collocation forms of optoelectronic functional materials are characterized by richness and diversity, and for OLED devices with different structures, the optoelectronic functional materials used have strong selectivity.

The spirobifluorene molecule has a non-planar spatial structure, and the two fluorene monomers are bridged together by the sp3 ^- hybridized C atom as the center. Introducing it into a molecule with electroluminescent properties has potential high application value for improving the thermal stability and spectral stability of the molecule.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a spirobifluorene structure organic compound containing a diarylamine substituted group, the compound has a non-planar steric structure, a higher glass transition temperature, suitable HOMO and LUMO energy levels, and With higher Eg, it can be sublimated without decomposition and without residue, which can effectively improve the luminescence performance of OLED devices and the life of OLED devices. It is suitable for phosphorescent and fluorescent (TADF-containing) OLED devices, especially in This is the case when the compound is used as hole injection material and/or hole transport material.

Specifically, the organic compound containing the spirobifluorene structure of the diarylamine substituted group of the present invention has the structure shown in the following chemical formula (1):

in,

Rings A, B and C exist alone or together, and each independently represents a substituted or unsubstituted condensed aryl or heteroaryl group having 6-18 carbon atoms on the ring;

Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ , Ar ₅ , Ar ₆ each independently represent a substituted or unsubstituted aryl group or a heterocyclic aryl group, and Ar ₁ and Ar ₂ may be connected to each other through E ₁ to form a ring , Ar ₃ and Ar ₄ can be connected to each other through E ₂ to form a ring, and Ar ₅ and Ar ₆ can be connected to each other through E ₃ to form a ring;

E ₁ , E ₂ , E ₃ each independently represent a direct bond, O, S, CRR' or NR, wherein R and R' each independently represent a C ₁ -C ₈ straight or branched chain alkyl, C ₁ -C C ₈ alkoxy, C ₇ -C ₁₄ aralkyl;

S ₁ , S ₂ , and S ₃ each independently represent a direct bond, a substituted or unsubstituted arylene group, a substituted or unsubstituted heteroarylene group;

m, n, and t each independently represent an integer from 0 to 3;

R ₁ , R ₂ , R ₃ , R ₄ each independently represent hydrogen, deuterium, halogen, nitrile, substituted or unsubstituted alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted substituted alkoxy, substituted or unsubstituted aryl, substituted or unsubstituted aryloxy, substituted or unsubstituted alkylaryl, substituted or unsubstituted aralkyl, substituted or unsubstituted aralkenyl, or substituted or unsubstituted heterocyclyl;

x and y each independently represent 0 or 1, and both are not 0 at the same time.

As a preferred technical solution of the present invention, rings A, B and C exist independently, that is, only A or B or C exists. Further preferably, rings A, B and C each independently represent a benzene ring.

Preferably, Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ , Ar ₅ , Ar ₆ each independently has 6-60 carbon atoms, and each independently represents a substituted or unsubstituted phenyl, substituted or unsubstituted phenyl group substituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted phenanthryl, substituted or unsubstituted fluorenyl, substituted or unsubstituted spirobifluorenyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted dibenzofuranyl, or Substituted or unsubstituted carbazolyl.

Preferably, S ₁ , S ₂ , and S ₃ each independently represent a direct bond, a C ₆ -C ₂₀ arylene group or a heteroarylene group. More preferably, S ₁ , S ₂ , and S ₃ represent direct bonds, that is, the spirobifluorene structure and the N atom are directly connected.

Preferably, R ₁ , R ₂ , R ₃ , R ₄ each independently represent hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2- Ethylhexyl, trifluoromethyl, pentafluoroethyl, phenyl, 1-naphthyl, 2-naphthyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, methoxy, ethoxy, n-Propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, 2-methylbutoxy, n-pentoxy, sec-pentoxy, neopentyl Oxy, cyclopentyloxy, n-hexyloxy, neohexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, Trifluoromethoxy, pentafluoroethoxy. More preferably, R ₁ , R ₂ , R ₃ , R ₄ each independently represent hydrogen or phenyl.

In a preferred embodiment of the present invention, S ₁ , S ₂ and S ₃ in the structure of formula (1) are all direct bonds, and rings A, B and C exist independently in a benzene ring structure. That is, the organic compound of the spirobifluorene structure of the present invention is selected from the compounds of the following formulas (2)-(4):

Further preferably, R ₁ , R ₂ , R ₃ , and R ₄ all represent hydrogen, that is, the organic compound of the spirobifluorene structure of the present invention is selected from the compounds of the following formulas (2-1)-(4-1):

Particularly preferably, the organic compound of the spirobifluorene structure of the present invention is selected from the compounds of formula (2-1), and the sum of x and y is equal to 1. That is, compounds of the following formulae (2-2) and (2-3) are preferred:

As a preferred technical solution, in the above general structures, Ar ₁ , Ar ₂ , Ar ₃ , Ar ₄ , Ar ₅ , and Ar ₆ are independently selected from the following structures:

Wherein, the dotted line represents the linking position with nitrogen; R ₅ independently represents methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, cycloheptyl, n-octyl , phenyl, 4-tert-butylphenyl, cycloalkyl.

Without limitation, the following are some preferred examples of the compounds described in the present invention:

After determining the above-mentioned organic compounds of the present invention and their structural characteristics, it is easy for those skilled in the art of organic chemistry to determine how to prepare the compounds. Practice has shown that the target product can be synthesized by a variety of routes.

Illustratively, the synthetic methods shown below are more preferable.

method one:

(1) Synthesis of compound of formula (2-2)

The raw material A is added with bromofluorenone under the action of n-butyllithium reagent to obtain intermediate alcohol B, which is hydrolyzed and cyclized to form dihalobenzospirobifluorene C, and then C-N is carried out step by step with diarylamine. In the coupling reaction, the monodiarylamine substituted compound D is obtained first, and then the compound of formula (2-2) is obtained.

(2) Synthesis of compound of formula (2-3)

The raw material A' is added with dihalofluorenone under the action of n-butyllithium reagent to obtain intermediate alcohol B', which is cyclized to form dihalobenzospirobifluorene C' after hydrolysis, and then combined with diarylamine The C-N coupling reaction is carried out step by step, firstly obtaining the compound D' substituted by monodiarylamine, and then obtaining the compound of formula (2-3).

Method Two:

Synthesis of compounds of formula (2-2)

Intermediate F is obtained by reacting methyl 1-bromo-2-naphthoate (E) with bromophenylboronic acid, which is then hydrolyzed to generate intermediate G, and intermediate H is obtained after ring formation; under the action of n-butyllithium reagent, intermediate Body H reacts with dihalogenated biphenyl to obtain intermediate alcohol B", and cyclization generates dihalogenated benzospirobifluorene C" after hydrolysis, and then carries out C-N coupling reaction step by step with diarylamine to obtain formula ( 2-2) Compounds.

It is easy to understand that in the above synthetic route, if the two diarylamine substituents in the final product are the same, the stepwise C-N coupling of the intermediate dihalobenzospirobifluorene and diarylamine can be simplified. In the reaction step, the product can be obtained directly by C-N coupling reaction of dihalogenated benzospirobifluorene and the same diarylamine.

As another object of the present invention, the present invention also relates to the application of the above-mentioned organic compound having a spirobifluorene structure containing a diarylamine substituted group in an OLED device, and an OLED device containing the organic compound.

As an exemplary embodiment, the OLED device includes: a first electrode; a second electrode disposed to face the first electrode; and one or more organic material layers disposed between the first electrode and the second electrode, wherein the organic One or more of the material layers contain the above-described organic compounds of the present invention.

The organic material layer may be constituted by a single-layer structure, or may be constituted by a multi-layer structure in which two or more organic material layers are stacked. For example, the light-emitting device of the present invention may have a structure including a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like as organic material layers. The device structure is not limited thereto, and may also include a smaller number of organic layers.

As another exemplary embodiment, the organic material layer includes a hole transport layer, and the hole transport layer includes the above-mentioned organic compound of the present invention.

As an exemplary embodiment, the organic material layer includes a hole injection layer and a hole transport layer, wherein the hole transport layer contains the above-mentioned organic compound of the present invention, and the hole injection layer uses the compound HAT-CN having the following structural formula:

As an exemplary embodiment, the organic material layer includes a hole injection layer containing the above-mentioned organic compound of the present invention.

Further, in addition to the above-mentioned organic compounds of the present invention, the hole injection layer also includes a p-type dopant material doped with a doping concentration of 1-20wt%, and the chemical structural formula of the p-type dopant material is as follows:

p-type doped material.

As an exemplary embodiment, the organic material layer includes a hole injection layer and a hole transport layer, and both the hole injection layer and the hole transport layer contain the above-mentioned organic compound of the present invention.

As an exemplary embodiment, the organic material layer further includes an electron blocking layer, and the electron blocking layer uses the compound HT2 of the following chemical structure:

As an exemplary embodiment, the organic material layer further includes a light-emitting layer, and the light-emitting layer uses compound BH as a host light-emitting body and compound BD as a guest light-emitting body, wherein the doping ratio of the guest light-emitting body is 1-10% by weight, and the ratio of the two is The chemical structural formula is as follows:

As an exemplary embodiment, the organic material layer further includes an electron transport layer, the electron transport layer uses the compound ET of the following chemical structure, and contains 50% by weight doped lithium quinolinolate (Lithium 8-quinolinolate, abbreviated as Liq):

As an exemplary embodiment, the organic material layer further includes an electron injection layer, and compounds that can be used for the electron injection layer include lithium fluoride (LiF), cesium fluoride (CsF), Liq, Yb, and the like.

Depending on the materials used, the OLED devices of the present invention can be top-emitting, bottom-emitting or bi-directional.

Using the above-mentioned organic compounds of the present invention for organic material layers of OLED devices, especially when used in hole injection and/or hole transport materials, can improve the efficiency of the device, reduce the driving voltage and/or improve the lifetime characteristics, the device It has low driving voltage and long service life, and exhibits highly stable device performance.

Description of drawings

Figure 1 is a schematic structural diagram of an OLED device in device application performance characterization; wherein,

1. Transparent substrate, 2. Anode layer, 3. Hole injection layer, 4. Hole transport layer, 5. Electron blocking layer, 6. Light-emitting layer, 7. Electron transport layer, 8. Electron injection layer, 9. Cathode Floor.

Detailed ways

The invention is explained in more detail by the following examples without wishing to limit the invention thereby. On the basis of this description, one of ordinary skill in the art will be able, without inventive step, to carry out the invention and to prepare other compounds according to the invention and to use these compounds in electronic devices within the full scope of the disclosure. Or use the method according to the present invention.

Preparation Examples

With reference to the synthetic procedures described above, intermediates and target compounds were prepared.

1. Synthesis of Intermediates

1.1 Synthesis of intermediate H (bromobenzofluorenone)

(1) Intermediate H1: 9-Bromo-7H-benzo[c]fluoren-7-one

Fully dry the experimental device, add methyl 1-bromo-2-naphthoate (E, 113mmol, 30g), p-bromophenylboronic acid (114mmol, 23g), 450mL of toluene, 20mL of ethanol, 200 mL of water, potassium carbonate (339 mmol, 47 g), tetrakis (triphenylphosphorus) palladium (1 mmol, 1.2 g), heated to 78 ° C to reflux, stirred for 5 h, TLC tracked the reaction progress of the raw materials; after the reaction was completed, the heating was stopped, The temperature was lowered to 25°C, and the solution was separated. After the organic phase was washed once with water, the solvent was distilled off under reduced pressure, and purified by column chromatography to obtain 23 g of off-white solid product F1 with a yield of 60%.

Fully dry the experimental device, add F1 (67.4mmol, 23g), 200mL of hydrobromic acid and 50mL of dichloromethane to a clean 500mL four-necked flask, heat up to 60°C for reflux, stir the reaction for 8h, and follow the reaction process of the raw materials by HPLC; After the reaction, the heating was stopped, the temperature was lowered to 25°C, the liquid was separated, the aqueous phase was extracted once with dichloromethane, the combined organic phases were washed once with water, the liquid was separated, the solvent was removed under reduced pressure, and purified by column chromatography to obtain a yellow solid product G1 17.6 g, 80% yield.

Fully dry the experimental device, add G1 (53.8mmol, 17.6g) and 250mL of 60% sulfuric acid solution into a clean 500mL four-necked flask, heat to 100°C, stir and react for 12h, and HPLC tracks the reaction process of the raw materials; Stop heating, cool down to 25°C, pour the reaction solution into a large amount of ice water, the product is precipitated, filtered, the filter cake is washed once with water, filtered to obtain the crude product; then heated and dissolved in dichloromethane, purified by column chromatography to obtain a yellow color The solid product is H1 8.3 g, and the yield is 50%.

The structure of the product H1 was characterized and the results are shown below.

¹ H NMR (CDCl ₃ , 400MHz) δ: 8.41～8.37 (d, J=8.0Hz, 1H), 7.90～7.23 (m, 8H);

IR(KBr)ν: 3059, 3018, 1760 cm ^-1 ;

MS[M+H] ⁺ =308.99.

(2) Intermediate H2-H4

Referring to the preparation method of intermediate H1, intermediates H2-H4 were synthesized by using different raw materials. The details are shown in Table 1 below.

Table 1

Note: 1. The raw materials of Example H2 and H3 are the same. According to the different ring-closing positions, two kinds of products can be obtained, and the two substances are separated by column chromatography.

2. The yield in Table 1 represents the actual yield of the last step reaction.

1.2 Synthesis of intermediate C (dihalogenated benzospirobifluorene)

(1) Intermediate C1: 2'-Bromo-9-chlorospiro[benzo[c]fluorene-7,9'-fluorene]

Fully dry the experimental device, add raw material A1 (126mmol, 40g) and dried tetrahydrofuran (400mL) to a 1L four-necked flask under nitrogen, stir and dissolve, use liquid nitrogen to cool down to below -78°C, slowly drop 50.6mL2 .5M (126mmol) n-BuLi n-hexane solution; after the dropwise addition, stir at -78°C for 1h, then add 2-bromo-9-fluorenone (126mmol, 32.6g) in batches at this temperature, dropwise After completion, it was incubated at -78°C for 1 h, and then stirred at room temperature for 12 h. After the reaction was completed, 4M hydrochloric acid solution was added dropwise to quench the reaction, extracted with ethyl acetate, the organic phase was washed with saturated brine, and spin-dried to remove the solvent to obtain the intermediate alcohol B1. In the case of not carrying out any purification, it was put into a 1L dry three-necked flask, 160mL of acetic acid and 5g of 36% hydrochloric acid were added, and the temperature was refluxed for 3h to complete the reaction. After cooling to room temperature, filter, wash twice with water, dry, and purify by column chromatography to obtain 35 g of off-white solid product C1 with a total yield of 58%.

The structure of the product C1 was characterized and the results are shown below.

¹ H NMR (CDCl ₃ , 400 MHz) δ: 8.70 (d, J=8.0 Hz, 1H), 8.23 (d, J=8.0 Hz, 1H), 7.89～7.83 (m, 3H), 7.73～7.49 (m, 4H), 7.34(t, J＝8.0Hz, 2H), 7.05(t, J＝8.0Hz, 2H), 6.89(s, 1H), 6.78～6.66(m, 2H);

IR(KBr)ν: 3060,3019 cm ^-1 ;

MS[M+H] ⁺ = 479.02

(2) Intermediate C2: 2'-chloro-9-bromospiro[benzo[c]fluorene-7,9'-fluorene]

Fully dry the experimental device, add 2-bromo-4'-chloro-1,1''-biphenyl (126mmol, 33.7g) and dried tetrahydrofuran (400mL) to a 1L four-necked flask under nitrogen, stir to dissolve After that, it was cooled down to below -78°C with liquid nitrogen, and 50.6mL of 2.5M (126mmol) n-BuLi n-hexane solution was slowly added dropwise; after the dropwise addition, it was stirred at -78°C for 1 h, and then H1 was added in batches at this temperature. (126mmol, 39g), after the dropwise addition, the mixture was kept at -78°C for 1h, and then stirred at room temperature for 12h. After the reaction was completed, 4M hydrochloric acid solution was added dropwise to quench the reaction, extracted with ethyl acetate, the organic phase was washed with saturated brine, and the solvent was removed by spin drying to obtain the intermediate alcohol B2. In the case of not carrying out any purification, it was put into a 1L dry three-necked flask, 160mL of acetic acid and 5g of 36% hydrochloric acid were added, and the temperature was refluxed for 3h to complete the reaction. After cooling to room temperature, filter, wash twice with water, dry, and purify by column chromatography to obtain 38.7 g of off-white solid product C2 with a total yield of 64%.

The structure of product C2 was characterized and the results are shown below.

¹ H NMR (CDCl ₃ , 400 MHz) δ: 8.70 (d, J=8.0 Hz, 1H), 8.23 (d, J=8.0 Hz, 1H), 7.89～7.83 (m, 3H), 7.70～7.45 (m, 4H), 7.34(t, J＝8.0Hz, 2H), 7.05(t, J＝8.0Hz, 2H), 6.84(s, 1H), 6.78～6.66(m, 2H);

IR(KBr)ν: 3060,3019 cm ^-1 ;

MS[M+H] ⁺ =479.03.

(3) Intermediate C3-C18

Referring to the preparation method of intermediate C1 or C2, intermediates C3-C18 were synthesized by using different starting materials. The details are shown in Table 2 below.

Table 2

1.3 Synthesis of Intermediate D (single diarylamine substituted halogenated benzospirobifluorene)

The final target compound can be obtained by step-by-step C-N coupling reaction of intermediate C and diarylamine. In this process, the difference in reactivity of different halogen-substituted groups can be utilized to obtain a single-diarylamine-substituted halogenated benzospirobifluorene, namely intermediate D, through a step-by-step C-N coupling reaction.

(1) Intermediate D1

The experimental device was fully dried, and 21.6 g (45 mmol) and 17.9 g of C1, 2'-bromo-9-chlorospiro[benzo[c]fluorene-7,9'-fluorene], were added to a 500 mL four-necked flask under nitrogen. (49.5mmol) N-[1,1'-biphenyl-4-yl]-9,9-dimethyl-9H-fluoren-2-amine, then add dry and degassed toluene as solvent, add 6.5 g (67.5 mmol) sodium tert-butoxide, 1.1 g (1.13 mmol) catalyst Pd ₂ (dba) ₃ and 1.2 g (2.25 mmol) 1,1'-bis(diphenylphosphino)ferrocene, warmed to 100- 105 ° C, the reaction 16h. After the reaction was completed, it was cooled to room temperature, diluted with toluene, filtered through silica gel, and the filtrate was evaporated to remove the solvent in vacuo to obtain a crude product. The crude product was purified by column chromatography to obtain 19.5 g of product D1 with a yield of 57%.

MS[M+H] ⁺ =759.25.

(2) Intermediate D2-D10

Intermediates D2-D10 were synthesized by using different starting materials. The details are shown in Table 3 below.

table 3

2. Synthesis of target compounds

The target compound of the present invention can be prepared by further C-N coupling reaction between the above-mentioned monodiarylamine-substituted halogenated benzospirobifluorene and diarylamine.

(1) Example 1: Synthesis of Compounds 1-12

The experimental device was fully dried, and D1 (34.2 g, 45 mmol) and N-phenyl-4-benzidine 12.1 g (49.5 mmol) were added to a 500 mL four-necked flask under nitrogen, and then dried and degassed toluene was added to make the solution. Solvent, add 6.5g (67.5mmol) sodium tert-butoxide and 0.88g (0.96mmol) catalyst Pd ₂ (dba) ₃ , heat up to 80°C, slowly drop 4.5mL of tri-tert-butylphosphine toluene with a mass concentration of 10% The solution was heated to 100-105°C after the dropwise addition, and reacted for 6h. After the reaction was completed, it was cooled to room temperature, diluted with toluene, filtered through silica gel, and the filtrate was evaporated to remove the solvent in vacuo to obtain a crude product. The crude product was purified by column chromatography to obtain 26.6 g of product 1-12 with a yield of 61%.

The structures of products 1-12 were characterized and the results are shown below.

¹ H NMR (CDCl ₃ , 400MHz)δ:8.20～7.85(m,8H),7.76(d,J=8.0Hz,4H),7.56(d,J=8.0Hz,5H),7.50(t,J= 8.0Hz, 4H), 7.48~7.40(m, 5H), 7.38(d, J=8.0Hz, 4H), 7.35~7.29(m, 4H), 7.27~7.19(m, 6H), 7.15~7.05(m ,5H),6.98(t,J=8.0Hz,1H),1.68(s,6H);

MS[M+H] ⁺ =968.42.

(2) Example 2: Synthesis of Compounds 1-98

Fully dry the experimental device, add C10 (23.6g, 45mmol) and N-phenyl-4-benzidine 22.3g (91mmol) to the four-necked flask under nitrogen, then add dry and degassed toluene as a solvent, 6.5g (67.5mmol) of sodium tert-butoxide and 0.88g (0.96mmol) of catalyst Pd ₂ (dba) ₃ were added, the temperature was raised to 80° C., and 4.5 mL of tri-tert-butylphosphine toluene solution with a mass concentration of 10% was slowly added dropwise. After the dropwise addition, the temperature was raised to 100-105°C, and the reaction was carried out for 6h. After the reaction was completed, it was cooled to room temperature, diluted with toluene, filtered through silica gel, and the filtrate was evaporated to remove the solvent in vacuo to obtain a crude product. The crude product was purified by column chromatography to obtain 25.7 g of product 1-98 with a yield of 67%.

The structures of products 1-98 were characterized and the results are shown below.

¹ H NMR (CDCl ₃ , 400MHz)δ:8.77～7.75(d,J=8.2Hz,1H),8.22～8.20(d,J=8.0Hz,1H),8.02～8.01(d,J=8.0Hz, 1H), 7.88～7.74(m, 4H), 7.76(d, J=8.0Hz, 4H), 7.57～7.54(m, 5H), 7.50(t, J=8.0Hz, 4H), 7.45～7.36(m ,9H),7.25～7.22(m,6H),7.10～7.00(m,9H);

MS[M+H] ⁺ =852.36.

(3) Embodiment 3-8

Referring to the preparation methods of compounds 1-12 and 1-98, different intermediates C or D and diarylamines were used as raw materials to synthesize the corresponding target compounds. The details are shown in Table 4 below.

Table 4

performance characterization

3. Compound physical properties

Taking some compounds as examples, the thermal properties, HOMO energy level and LUMO energy level of the organic compounds of the present invention are detected. The detected objects and their results are shown in Table 5 below.

table 5

compound Tg Td HOMO LUMO functional layer 1-2 157 480 5.22 2.28 HIL, HTL, EBL, EML 1-36 160 488 5.29 2.26 HIL, HTL, EBL, EML 1-6 165 492 5.38 2.25 HIL, HTL, EBL, EML 1-43 172 497 5.43 2.27 HIL, HTL, EBL, EML 1-86 189 502 5.45 2.23 HIL, HTL, EBL, EML

Among them, the glass transition temperature Tg was measured by differential scanning calorimetry (DSC, DSC25 differential scanning calorimeter of TA Company in the United States), and the heating rate was 10 °C/min; The measurement was carried out on a TGA55 thermogravimetric analyzer of TA Company in the United States, and the nitrogen flow rate was 20 mL/min; the highest occupied molecular orbital HOMO energy level and the lowest unoccupied molecular orbital LUMO energy level were measured by cyclic voltammetry.

From the data in Table 5, it can be seen that the compound of the present invention has a higher glass transition temperature, which can ensure the thermal stability of the compound, thereby avoiding the transformation of the amorphous film of the compound into a crystalline film, so that the produced compound containing the organic compound of the present invention can be prepared. The lifetime of the OLED device is improved. Meanwhile, the compounds of the present invention have different HOMO and LOMO energy levels, and can be applied to different functional layers of OLED devices.

In particular, as shown in Table 5, the organic compounds of the present invention are particularly suitable for use in hole injection layers (HIL), hole transport layers (HTL), electron blocking layers (EBL) and/or light emitting layers ( EML). They are available as separate layers or as mixed components in HIL, HTL, EBL or EML.

4. OLED device application

Below in conjunction with FIG. 1 , the application effects of the organic compounds of the present invention as materials of different functional layers in OLED devices will be described in detail through Device Examples 1-10 and Comparative Examples 1-2.

Other materials used in the device examples and the comparative examples are all existing known products on sale, which can be purchased from the market. The structural formula of the organic material used is as follows:

(1) Device Example 1

Referring to the structure shown in FIG. 1, to manufacture an OLED device, the specific steps are as follows: the glass substrate (Corning glass 50mm*50mm*0.7mm) plated with ITO (indium tin oxide) with a thickness of 130nm is ultrasonically washed with isopropanol and pure water respectively 5 minutes, then cleaned with ultraviolet ozone, and then the glass substrate was transferred to the vacuum deposition chamber; the hole injection material HAT-CN was thermally deposited on the transparent ITO electrode with a thickness of 5nm in vacuum (about ^10-7 Torr), thereby forming a hole injection layer; vacuum deposition of compound 1-2 with a thickness of 140 nm on the hole injection layer to form a hole transport layer; vacuum deposition of HT2 with a thickness of 10 nm on the hole transport layer to form an electron blocking layer; as a light-emitting layer, Vacuum deposition of host BH and 4% guest dopant BD to a thickness of 25 nm; formation of an electron transport layer using an ET compound doped with 50% Liq (lithium quinolate) to a thickness of 25 nm; and final sequential deposition of 1 nm Thick lithium fluoride (electron injection layer) and 100 nm thick aluminum formed the cathode; the device was transferred from the deposition chamber to a glove box, where it was encapsulated with UV curable epoxy resin and a glass cover plate containing a moisture absorbent.

The device structure is expressed as: ITO(130nm)/HAT-CN(5nm)/Compound 1-2(140nm)/HT2(10nm)/BH:BD(25nm)/ET:Liq(25nm)/LiF(1nm)/ Al (100 nm). The device structure of the fabricated OLED light-emitting device is shown in Table 6, and the test results are shown in Table 7.

In the above-mentioned fabrication steps, the deposition rates of organic material, lithium fluoride, and aluminum were maintained at 0.1 nm/s, 0.05 nm/s, and 0.2 nm/s, respectively.

(2) Device Example 2

Experiments were carried out in the same manner as in Device Example 1, except that Compound 1-36 was used instead of Compound 1-2 in Example 1 as the hole transport layer. The device structure of the fabricated OLED light-emitting device is shown in Table 6, and the test results are shown in Table 7.

(3) Device Example 3

Experiments were carried out in the same manner as in Device Example 1, except that Compound 1-6 was used instead of Compound 1-2 in Example 1 as the hole transport layer. The device structure of the fabricated OLED light-emitting device is shown in Table 6, and the test results are shown in Table 7.

(4) Device Example 4

Experiments were carried out in the same manner as in Device Example 1, except that Compound 1-43 was used instead of Compound 1-2 in Example 1 as the hole transport layer. The device structure of the fabricated OLED light-emitting device is shown in Table 6, and the test results are shown in Table 7.

(5) Device Example 5

Experiments were carried out in the same manner as in Device Example 1, except that Compound 1-86 was used instead of Compound 1-2 in Example 1 as the hole transport layer. The device structure of the fabricated OLED light-emitting device is shown in Table 6, and the test results are shown in Table 7.

(6) Comparative Example 1

Experiments were carried out in the same manner as in Device Example 1, except that HT1 was used instead of Compound 1-2 in Example 1 as the hole transport layer. The device structure of the fabricated OLED light-emitting device is shown in Table 6, and the test results are shown in Table 7.

Table 6

Compared with Comparative Example 1, the device manufacturing process in the above device Examples 1-5 is completely the same, and the same substrate and electrode material are used, and the film thickness of the electrode material is also the same, the difference is the hole in the device. The transport material HT1 was replaced. Table 7 shows the test results of the performance of the devices obtained in each embodiment at a current density of 10 mA/cm ² .

Table 7

Among them, the luminous color is identified and defined by the CIE _{x, y} chromaticity coordinates; the driving voltage refers to the voltage with a luminance of 1cd/m ² ; the current efficiency refers to the luminous luminance at a unit current density; The generated luminous flux; external quantum efficiency (EQE) refers to the ratio of the number of photons emitted from the surface of the component to the number of injected electrons in the observation direction; LT95@1000nits refers to 1000nits as the initial brightness, the device is under constant current conditions The time when the brightness is reduced from the initial 100% to 95%.

As shown in the above table, the compounds used in Device Examples 1-5 are used as hole transport layers in organic light emitting devices, and have excellent hole transport ability compared with benzidine type material HT1, exhibiting low voltage and High efficiency features. At the same time, it exhibits better stability and lifetime based on high triplet energy (a characteristic of spiro ring materials). It can be seen that the organic light-emitting device comprising the present invention has low driving voltage and long service life, and exhibits highly stable device performance.

In order to further verify the application performance advantage of the present invention, referring to the method of the above-mentioned Example 1, an OLED device having the structure shown in Table 8 was manufactured.

Table 8

Compared with Comparative Example 2, the device manufacturing process of the device Examples 6-10 of the present invention is completely the same, and the same substrate and electrode materials are used, and the film thickness of the electrode materials is also the same. The hole injection material and hole transport material were replaced, and the hole injection layer was doped with 2wt% p-type dopant material.

The devices obtained in the above device Examples 6-10 and Comparative Example 2 were tested for performance at a current density of 10 mA/cm ² , and the results are shown in Table 9.

Table 9

The compounds used in the device examples 6-10 are used as the host material of the hole injection layer and the hole transport layer in the organic light-emitting device. It has excellent hole injection and transport ability and shows low voltage and high efficiency characteristics, and at the same time, it also shows better stability and life. It can be seen that the organic light-emitting device comprising the present invention has low driving voltage and long service life, and exhibits highly stable device performance.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (22)

1. An organic compound of a spirobifluorene structure containing diarylamine substituent groups has a structure represented by the following chemical formula (1):

wherein,

ring A, B and C, independently or simultaneously, each independently represent a condensed aryl or heteroaryl group having 6 to 18 carbon atoms in the ring, substituted or unsubstituted;

Ar₁、Ar₂、Ar₃、Ar₄、Ar₅、Ar₆each independently represents a substituted or unsubstituted aryl or heterocyclic aryl group, and Ar₁And Ar₂Can pass through E₁Are linked to each other to form a ring, Ar₃And Ar₄Can pass through E₂Are linked to each other to form a ring, Ar₅And Ar₆Can pass through E₃Are connected with each other to form a ring;

E₁、E₂、E₃each independently represents a direct bond, O, S, CRR 'or NR, wherein R and R' each independently represents C₁-C₈Straight or branched alkyl of (2), C₁-C₈Alkoxy group of (C)₇-C₁₄Aralkyl group of (1);

S₁、S₂、S₃each independently represents a direct bond, a substituted or unsubstituted arylene, a substituted or unsubstituted heteroarylene;

m, n, t each independently represent an integer of 0 to 3;

R₁、R₂、R₃、R₄each independently represents hydrogen, deuterium, halogen, a nitrile group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkylaryl group, a substituted or unsubstituted arylalkyl group, a substituted or unsubstituted arylalkenyl group, or a substituted or unsubstituted heterocyclic group;

x and y each independently represent 0 or 1, and both are not 0 at the same time.

2. An organic compound according to claim 1, characterized in that: ring A, B and C exist separately.

3. An organic compound according to claim 1 or 2, characterized in that: ring A, B and C each independently represent a benzene ring.

4. An organic compound according to claim 1, characterized in that: ar (Ar)₁、Ar₂、Ar₃、Ar₄、Ar₅、Ar₆Each independently has 6-60Carbon atom, and each independently represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted tetrabiphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted spirobifluorenyl group, a substituted or unsubstituted dibenzothienyl group, a substituted or unsubstituted dibenzofuranyl group, or a substituted or unsubstituted carbazolyl group.

5. An organic compound according to claim 1, characterized in that: s₁、S₂、S₃Each independently represents a direct bond, C₆-C₂₀Arylene or heteroarylene of (a); more preferably, S₁、S₂、S₃Representing a direct bond.

6. An organic compound according to claim 1, characterized in that: r₁、R₂、R₃、R₄Each independently represents hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, phenyl, 1-naphthyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, 2-methylbutyloxy, n-pentoxy, sec-pentoxy, neopentoxy, cyclopentoxy, n-hexoxy, neohexoxy, cyclohexoxy, n-heptoxy, cycloheptoxy, n-octoxy, cyclooctoxy, 2-ethylhexoxy, 2-methylbutyloxy, 2-methylo, Trifluoromethoxy, pentafluoroethoxy; more preferably, R₁、R₂、R₃、R₄Each independently represents hydrogen or phenyl.

7. The organization of claim 1A compound characterized by: s₁、S₂And S₃Both are direct bonds, ring A, B and C exist independently as a benzene ring structure;

namely, the organic compound is selected from the group consisting of compounds of the following formulae (2) to (4):

8. the organic compound of claim 7, wherein: r₁、R₂、R₃、R₄All represent hydrogen; namely, the organic compound is selected from the compounds of the following formulae (2-1) to (4-1):

9. the organic compound of claim 8, wherein: the organic compound is selected from compounds of formula (2-1) and the sum of x and y is equal to 1; namely, a compound selected from the following formulae (2-2) and (2-3):

10. the organic compound according to any one of claims 1 to 9, wherein: in each general structure, Ar₁、Ar₂、Ar₃、Ar₄、Ar₅、Ar₆Each independently, is selected from the following structures:

wherein the dotted line represents a linking site bonded to nitrogen; r₅Each independently represents methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, cycloheptyl, cyclopentyl,N-octyl, phenyl, 4-tert-butylphenyl, cycloalkyl.

11. The method for producing an organic compound according to claim 9, wherein the following method is employed:

the method comprises the following steps:

(1) synthesis of Compound of formula (2-2)

Performing addition reaction on a raw material A and bromofluorenone under the action of an N-butyllithium reagent to obtain an intermediate alcohol B, performing cyclization after hydrolysis to generate dihalogenated benzospirobifluorene C, and performing C-N coupling reaction with diarylamine step by step to obtain a compound D substituted by the monodiarylamine and then obtain a compound of a formula (2-2);

(2) synthesis of Compound of formula (2-3)

Adding a raw material A 'and dihalofluorenone under the action of an N-butyllithium reagent to obtain an intermediate alcohol B', hydrolyzing and cyclizing to generate dihalogenated benzospirobifluorene C ', and then carrying out C-N coupling reaction with diarylamine step by step to obtain a compound D' substituted by the monodiarylamine and then obtain a compound of a formula (2-3);

the second method comprises the following steps:

synthesis of Compound of formula (2-2)

Reacting 1-bromo-2-methyl naphthoate (E) with bromobenzylboronic acid to obtain an intermediate product F, hydrolyzing to generate an intermediate G, and cyclizing to obtain an intermediate H; under the action of an N-butyllithium reagent, reacting the intermediate H with dihalobiphenyl to obtain an intermediate alcohol B, performing cyclization after hydrolysis to generate dihalogenated benzospirobifluorene C ", and then performing C-N coupling reaction with diarylamine step by step to obtain the compound shown in the formula (2-2).

12. The method of claim 11, wherein: the two diarylamine substituents in the final product are the same, the step of stepwise C-N coupling reaction of the intermediate dihalogenated benzospirobifluorene and diarylamine is simplified, and the dihalogenated benzospirobifluorene and the same diarylamine are directly subjected to C-N coupling reaction to obtain the product.

13. Use of an organic compound according to any one of claims 1 to 10 in an OLED device.

An OLED device comprising the organic compound of any one of claims 1-10.

15. The OLED device of claim 14 including: a first electrode; a second electrode disposed to face the first electrode; and one or more organic material layers disposed between the first electrode and the second electrode, wherein one or more of the organic material layers contain the organic compound.

16. The OLED device of claim 15, wherein: the organic material layer includes a hole transport layer, and the hole transport layer contains the organic compound.

17. The OLED device of claim 15, wherein: the organic material layer includes a hole injection layer and a hole transport layer, wherein the hole transport layer contains the organic compound, and the hole injection layer uses a compound HAT-CN having the following structural formula:

18. the OLED device of claim 15, wherein: the organic material layer includes a hole injection layer containing the organic compound.

19. The OLED device of claim 18, wherein: the hole injection layer contains, in addition to the organic compound, a p-type doping material doped at a doping concentration of 1-20 wt%, the p-type doping material having the following chemical formula:

20. the OLED device of claim 15, wherein: the organic material layer includes a hole injection layer and a hole transport layer, and both the hole injection layer and the hole transport layer contain the organic compound.

21. The OLED device of claim 15, wherein: the organic material layer further comprises at least one of an electron blocking layer, a light emitting layer, an electron transport layer and an electron injection layer; wherein,

the electron blocking layer uses compound HT2 of the following chemical structure:

the luminescent layer uses a compound BH as a main luminophor and a compound BD as a guest luminophor, wherein the doping proportion of the guest luminophor is 1-10 wt%, and the chemical structural formulas of the two are as follows:

the electron transport layer uses compound ET of the following chemical structure and comprises quinoline lithium doped with 50% by weight:

the electron injection layer uses a compound selected from lithium fluoride (LiF), cesium fluoride (CsF), Liq, Yb.

22. The OLED device of any one of claims 14-21, wherein: the OLED device is of a top emission type, a bottom emission type, or a bi-directional emission type.

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