An oxygen ether bridged perylene imide derivative and its preparation method and application

Abstract

The present invention discloses an oxygen ether bridged perylene imide derivative, characterized in that the general structural formula thereof is shown in Formula I: wherein the substituent Ar is an aromatic ring group, the substituent position thereof is the bay area of ​​the perylene imide unit, and the substituent R is selected from C1 to C 30 The present invention utilizes oxygen ether bridged perylene imide monomers, and the obtained oxygen ether bridged perylene imide derivatives have excellent photoelectric conversion efficiency and high open circuit voltage when used as electron acceptor materials in organic solar cells, and have great application potential in the fields of organic solar cell acceptor materials and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of organic semiconductors, and in particular relates to an oxygen ether-bridged perylene imide derivative and an application thereof in an organic solar cell. Background Art

[0002] Organic solar cells (OSCs) are an important emerging photovoltaic material due to their thinness, flexibility, foldability, bendability, and stretchability, as well as their ability to be produced on a large scale using low-energy roll-to-roll printing, inkjet printing, and other solution processing methods.

[0003] At present, the bulk heterojunction (BHJ) structure formed by electron donors and electron acceptors has become the mainstream structure of the OSC working layer. In order to improve energy conversion efficiency, stability and reduce costs, the research on organic electron donor and acceptor materials has become a top priority. The efficiency of PDI-type acceptor materials has been continuously improved in recent years, reaching more than 12%. It has the advantages of a wide range of raw material sources, simple synthesis steps, low cost and high stability. Therefore, the research on PDI-type acceptor materials is still of great significance. Summary of the invention

[0004] The main purpose of the present invention is to provide an oxygen ether-bridged perylene imide derivative, which exhibits greater electron affinity by utilizing the oxygen ether-bridged perylene imide, significantly enhances the distortion of the molecular skeleton, and promotes a good phase separation morphology of the blended film; the obtained oxygen ether-bridged perylene imide derivative is used as an electron acceptor material, which can obtain excellent photoelectric conversion efficiency and high open circuit voltage, and has great application potential in the field of organic solar cell acceptor materials; at the same time, the use of catalysts such as precious metals can be avoided during the synthesis process, effectively reducing the preparation cost while avoiding the difficulty in removing metal catalysts and the harmful effects of residual catalysts on photovoltaic performance; and is suitable for popularization and application.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] An oxygen ether bridged perylene imide derivative, the general structural formula of which is shown in Formula I:

[0007]

[0008] In the formula, the substituent Ar is an aromatic ring group, the substitution position is the bay area of ​​the perylene imide unit, and the substituent R is selected from C 1 ~C 30 Alkyl chain; the value of n is 2 to 6.

[0009] In the above scheme, the Ar group is one or more selected from spirobifluorenyl, phenyl, biphenyl, benzodithienyl, triphenylamine, tetraphenylphenylphenyl, thienyl, triazine and the like.

[0010] Furthermore, the substituent R is C 5 ~C 30 The alkyl chain has the structural formula C m H 2m+1 , m is an integer between 5 and 30.

[0011] Furthermore, the Ar group is a phenyl group, and when n=3, the structure of the oxygen ether-bridged perylene imide derivative is as follows:

[0012]

[0013] Furthermore, the Ar group is a biphenyl group, and when n=4, the structure of the oxygen ether-bridged perylene imide derivative is as follows:

[0014]

[0015]

[0016] The preparation method of the above-mentioned oxygen ether bridged perylene imide derivative comprises the following steps: dispersing monobromoperylene imide, Ar unit connected with hydroxyl group and Lewis base in an organic solvent in proportion, heating to carry out Williamson synthesis reaction, quenching the reaction (quenching with water), washing and extracting, combining the organic phases and drying them by spin drying, and finally performing column chromatography separation to obtain the oxygen ether bridged perylene imide derivative.

[0017] In the above scheme, the Lewis base can be selected from Na 2 CO 3 or K 2 CO 3 etc. are weaker Lewis bases.

[0018] In the above scheme, the structural formula of the monobrominated perylene imide is shown in Formula II;

[0019]

[0020] In the formula, R is C 5 ~C 30 of the alkyl chain.

[0021] In the above scheme, the structural formula of the Ar unit connected with a hydroxyl group is shown in Formula III;

[0022] Ar[OH] n (III);

[0023] Wherein, n ranges from 2 to 6.

[0024] Furthermore, the Ar[OH] nPhloroglucinol, 5-bromoresorcinol, hydroquinone, resorcinol, catechol, etc. can be used.

[0025] In the above scheme, the molar ratio of the monobromoperylene imide, the Ar unit connected with a hydroxyl group and potassium carbonate is 2-8:1:2-40.

[0026] In the above scheme, the organic solvent can be selected from one or more aprotic polar solvents such as N,N-dimethylformamide, DMSO, tetrahydrofuran, etc.

[0027] In the above scheme, the heating reaction temperature is room temperature to 120° C., and the time is 5 to 96 hours.

[0028] Furthermore, when the Ar group is a biphenyl group and n=4, the preparation method of the oxygen ether bridged perylene imide derivative may further comprise the following steps:

[0029] 1) Monobromoperylene imide, bromobenzene and Lewis base (Na 2 CO 3 or K 2 CO 3 and a weaker Lewis base) are dispersed in an organic solvent in proportion, heated to perform a Williamson synthesis reaction, the reaction is quenched (quenched with water), the organic phases are combined after washing and extraction and spin-dried, and finally separated by column chromatography to obtain a bromooxyether-bridged perylene imide monomer;

[0030] 2) subjecting the bromine oxygen ether-bridged perylene imide monomer to an Ullmann coupling reaction to obtain the oxygen ether-bridged perylene imide derivative.

[0031] In the above scheme, the bromobenzene is 5-bromoresorcinol or 4-bromo-1,2-benzene, etc.

[0032] In the above scheme, the structural formula of the bromine oxygen ether bridged perylene imide monomer is shown in Formula IV;

[0033]

[0034] In the above scheme, a preparation method of the monobrominated perylene imide comprises the following steps: adding dichloromethane solvent to an alkyl-modified perylene imide monomer, then adding liquid bromine, performing a reflux reaction, washing with a sodium hydroxide aqueous solution, extracting, drying, and then performing column chromatography to obtain the monobrominated perylene imide.

[0035] In the above scheme, the structural formula of the alkyl-modified perylene imide monomer is shown in Formula V:

[0036]

[0037] In the formula, R is C 5~C 30 of the alkyl chain.

[0038] In the above scheme, the molar ratio of the monobrominated perylene imide to liquid bromine is 1:(30-55).

[0039] In the above scheme, the reflux reaction time is 3 to 8 hours.

[0040] In the above scheme, a preparation method of the alkyl-modified perylene imide monomer comprises the following steps: adding 3,4,9,10-perylenetetracarboxylic dianhydride (structure shown in Formula VI), zinc acetate, amino long-chain alkane, and imidazole into a reaction container, heating under a protective atmosphere until the imidazole is completely melted, stirring and reacting at 80 to 155° C. for 5 to 48 hours, stopping heating, and cooling to room temperature; washing with hydrochloric acid aqueous solution, extracting, drying, and then performing column chromatography to obtain the alkyl-modified perylene imide (structure shown in Formula V).

[0041] In the above scheme, the number of carbon atoms in the amino long-chain alkane is 5 to 30.

[0042] Furthermore, the amino long-chain alkane can be selected from 6-aminoundecane or 3-aminopentane.

[0043] In the above scheme, the structural formula of the 3,4,9,10-perylenetetracarboxylic dianhydride monomer is shown in Formula VI;

[0044]

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] 1) The present invention can regulate moderate distortion through the oxygen ether bridge structure, which is beneficial to weaken the aggregation between molecules while forming moderate aggregation, and promotes good phase separation morphology of the blended film; the aromatic ring group core of the present invention uses the oxygen ether bridge structure to connect three or four PDI units to form a highly three-dimensional PDI trimer or tetramer, and the formation of a large conjugated structure is more conducive to further improving the photoelectric performance;

[0047] 2) The synthesis process involved in the present invention is simple and easy to operate; it can effectively avoid the problems that the expensive palladium catalysts in the widely used palladium-catalyzed cross-coupling reactions (such as Stille, Suzuki-Mayier, Sonogashira, Buchwald-Hartwig, or direct (hetero) aromatic reactions) when constructing these three-dimensional PDI-based non-fullerene receptors in the traditional process are difficult to remove and the residual catalysts have a harmful effect on photovoltaic performance. The present invention does not require the use of precious metal catalysts to synthesize PDI polymers, which can effectively reduce costs and eliminate the adverse effects of residual catalysts on photovoltaic performance, which helps to cater to large-scale production in the market;

[0048] 3) When the oxygen ether-bridged perylene imide derivative of the present invention is used as an electron acceptor material, it has excellent photoelectric conversion efficiency and high open circuit voltage, which can provide a new idea for the preparation of high-performance organic solar cells. DETAILED DESCRIPTION

[0049] In order to enable ordinary technicians in the field to fully understand the technical solutions and beneficial effects of the present invention, the following is further described in conjunction with specific examples. The following examples are only preferred embodiments of the present invention and do not constitute any limitation to the present invention. Any equivalent changes and improvements made on this basis should fall within the scope of protection of the present invention.

[0050] In the following examples, the method for preparing the alkyl-modified perylene imide monomer (PDI monomer) comprises the following steps:

[0051] 3,4,9,10-perylenetetracarboxylic dianhydride (15 g, 38.23 mmol, 1 eq), zinc acetate (5.26 g, 28.68 mmol, 2.3 eq), 6-aminoundecane (15.07 g, 87.94 mmol, 0.75 eq), imidazole (120 g, 1.76 mol, 46.1 eq) were added into a two-necked round-bottom flask, heated to 155° C. in a nitrogen environment to completely melt the imidazole, stirred at 155° C. for 24 h, then stopped heating and cooled to room temperature; washed with hydrochloric acid aqueous solution, extracted, dried, and then subjected to column chromatography to obtain the alkyl-modified perylene imide; the specific reaction route is as follows:

[0052]

[0053] In the following examples, the method for preparing monobromoperylene diimide (N,N'-(6-undecyl)-6-bromo-perylene diimide) comprises the following steps:

[0054] In an air atmosphere, dichloromethane is added to an alkyl-modified perylene imide monomer, and then liquid bromine is added to reflux for 3 hours (the corresponding molar ratio of the two reaction raw materials is 1:55), washed with sodium hydroxide aqueous solution, extracted, dried and then column chromatographed to obtain the monobromoperylene imide; the specific reaction route is as follows:

[0055]

[0056] In the following examples, the method for preparing monobromoperylene diimide (N,N'-(6-undecyl)-2-bromo-perylene diimide) comprises the following steps:

[0057] 1) PDI (1 g, 1.89 mmol, 1 eq), biboric acid pinacol ester (0.75 g, 2.95 mmol, 1.5 eq), [Ir(OMe)cod] 2 (38 mg, 0.06 mmol, 0.03 eq) and tris(pentafluorophenyl)phosphine (120 mg, 0.24 mmol, 0.13 eq) were added to a reaction tube, and 5 ml of 1,4-dioxane was used as a solvent; the mixture was stirred at 110° C. under an argon atmosphere, and after 48 hours, the solvent was removed under reduced pressure, and the residue was purified by silica gel column chromatography using dichloromethane as an eluent to obtain molecule VII;

[0058] 2) VII (1 g, 1.52 mmol, 1 eq) and copper bromide (0.68 g, 3.04 mmol, 2 eq) were added to a mixture of 1,4-dioxane (20 ml), methanol (2 ml) and water (1 ml), and stirred at 90° C. under argon. After 12 hours, the reaction was cooled to room temperature, and then extracted, dried and column chromatographed to obtain the monobromoperylene diimide (N,N'-(6-undecyl)-2-bromo-perylene diimide); the specific reaction route is as follows.

[0059]

[0060] Example 1

[0061] An oxygen ether bridged perylene imide derivative, the preparation method of which comprises the following steps:

[0062] Under argon protection atmosphere, N,N'-(6-undecyl)-6-bromo-perylene diimide (215.88 mg, 277.53 umol, 3.5 eq), phloroglucinol (10 mg, 79.30 μmol, 1 eq) and potassium carbonate (32.88 mg, 237.89 μmol, 3.5 eq) were added to 8 ml of N,N-dimethylformamide and reacted at 80°C for 24 h. The product was washed with water and extracted three times with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, and then the solvent was removed by rotary evaporation. The target product 3a was obtained by silica gel column chromatography using dichloromethane as the eluent. The specific reaction route is as follows:

[0063]

[0064] The hydrogen nuclear magnetic resonance characterization results of the target product 3a obtained in this example include: 1H NMR (500 MHz, Chloroform-d) δ9.41 (d, 3H), 8.65 (m, 18H), 6.88 (s, 3H), 5.15 (m, 6H), 2.19 (m, 12H), 1.83 (m, 12H), 1.25 (m, 12H), 1.25 (m, 72H), 0.81 (m, 36H). MALDI-TOF: [ben-3oPDI] calculated for 2216.839.

[0065] Example 2

[0066] An oxygen ether bridged perylene diimide derivative, the preparation method of which is similar to that of Example 1, except that the reactant N,N'-(6-undecyl)-6-bromo-perylene diimide is replaced by N,N'-(6-undecyl)-2-bromo-perylene diimide, and the specific reaction route is as follows.

[0067]

[0068] The hydrogen nuclear magnetic resonance characterization results of the target product 3a' obtained in this example include: 1H NMR (500 MHz, Chloroform-d) δ9.61 (d, 3H), 8.55 (m, 18H), 6.78 (s, 3H), 5.14 (m, 6H), 2.50 (m, 12H), 1.85 (m, 12H), 1.35 (m, 12H), 1.15 (m, 72H), 0.71 (m, 36H).

[0069] Example 3

[0070] An oxygen ether bridged perylene imide derivative, the preparation method of which comprises the following steps:

[0071] 1) Under an argon atmosphere, N,N'-(6-undecyl)-6-bromo-perylene diimide (1 g, 1.29 mmol, 2.5 eq), 5-bromoresorcinol (100 g, 529.08 μmol, 1 eq) and potassium carbonate (219.36 mg, 1.59 mmol, 3.eq) were added to 20 ml of N,N-dimethylformamide and reacted at 80°C for 24 h. The product was washed with water and extracted three times with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, and then the solvent was removed by rotary evaporation. The product was separated by silica gel column chromatography using dichloromethane as the eluent to obtain compound 3b'; 1H NMR(500MHz,Chloroform-d)δ9.40(d,2H),8.70(m,10H),8.39(m,2H)7.16(m,1H),7.02(m,1H),5.16 (m,4H),2.22(m,8H),1.82(m,8H),1.26(m,48H),0.79(m,24H).MALDI-TOF:[ben-2oPDI]calculated for 1582.856;

[0072] 2) Under argon protection atmosphere, compound 3b' (540 mg, 340.15 umol, 1 eq) and copper powder (216.79 mg, 3.41 mmol, 10 eq) were added to 2 ml of N,N-dimethylformamide and reacted at 100°C for 24 h. The product was washed with water and extracted three times with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, and then the solvent was removed by rotary evaporation. The target product 3b was separated by silica gel column chromatography using dichloromethane as the eluent to obtain 1H NMR(500MHz,Chloroform-d)δ8.21(m,12H),7.85(m,12H),7.32(m,4H),7.05(m,4H),6.65(m,2H),4.05 (m,8H),1.51(m,32H),1.29(m,32H),1.28(m,64H),0.88(m,48H).MALDI-TOF:[ben-4oPDI]calculated for 3005.906;

[0073] The specific reaction route is as follows:

[0074]

[0075] Example 4

[0076] An oxygen ether-bridged perylene imide derivative, the preparation method of which is substantially the same as that of Example 2, except that 5-bromoresorcinol used in step 1) is replaced by 4-bromo-1,2-benzenediol; the hydrogen nuclear magnetic resonance characterization results of the obtained product 4b include: 1HNMR (500 MHz, Chloroform-d) δ8.64 (m, 8H), 8.56 (m, 4H), 8.32 (m, 2H), 8.10 (m, 6H), 7.99 (m, 6H), 7.85 (m, 8H), 5.05 (m, 8H), 2.16 (m, 24H), 1.81 (m, 32H), 1.18 (m, 64H), 0.77 (m, 48H).

[0077] The specific reaction route is as follows:

[0078]

[0079] Application Example 1

[0080] The oxygen ether bridged perylene imide derivative obtained in Example 1 of the present invention is applied to the active layer material of an organic solar cell. The specific steps include: using 3a in Example 1 as an acceptor material to prepare an organic solar cell, and the structure of the organic solar cell is ITO / PEDOT:PSS / PTB7-Th:3a / PNDIT-F3N / Al; the specific preparation process is:

[0081] First, the ITO glass was cleaned, first scrubbed with a cleaning agent, then washed with deionized water and ultrapure water. Then, the ITO glass was ultrasonically cleaned with acetone and isopropanol as solvents for about 30 minutes each, and then dried with nitrogen. It was treated with plasma for 2 minutes, and then spin-coated with PEDOT-PSS (Baytron PVP 4083) (rotation speed 4000rpm, time 40 seconds) as a hole transport layer, and dried at 150℃ for 20 minutes. Then, the 1,2-dichlorobenzene solution of PTB7-Th:3a (w / w=1:1.5) was spin-coated (rotation speed 2000rpm, time 45 seconds) on the surface of PEDOT:PSS as an active layer, and then thermally annealed at 100℃ for 10 minutes. After annealing, PNDIT-F3N (rotation speed 2500rpm, time 40 seconds) was spin-coated on the surface of the active layer as an electron transport layer, and then the metal electrode Al (100nm) was evaporated to obtain an organic solar cell device.

[0082] After testing: Under standard sunlight (AM 1.5G), the device performance of the organic solar cell was tested. Among them, the open circuit voltage of the bulk heterojunction organic solar cell device prepared with 3a as the acceptor material was 0.92V and the short circuit current was 7.55mA / cm 2, the filling factor is 0.44 and the photoelectric conversion efficiency is 4.50%.

[0083] Application Example 2

[0084] An organic solar cell was prepared using 3b prepared in Example 2 of the present invention as an acceptor material. The structure of the organic solar cell was ITO / PEDOT:PSS / PTB7-Th:3b / PNDIT-F3N / Al. The specific preparation process was the same as in Example 1.

[0085] After testing, the open circuit voltage of the bulk heterojunction organic solar cell device prepared with 3b as the acceptor material is 1.13V and the short circuit current is 7.82mA / cm 2 , the filling factor is 0.52, and the photoelectric conversion efficiency is 5.60%.

[0086] The above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, so the obvious changes or modifications derived are still within the protection scope of the invention.

Claims

1. An oxygen ether bridged perylene imide derivative, characterized in that: Its general structural formula is shown in Formula I: In the formula, the substituent R is selected from C1 to C 30 The alkyl chain of Wherein, the Ar group is a phenyl group, and when n=3, the structure of the oxygen ether-bridged perylene imide derivative is as follows: When the Ar group is a biphenyl group and n=4, the structure of the oxygen ether bridged perylene imide derivative is as follows:

2. The oxygen ether bridged perylene imide derivative according to claim 1, characterized in that: The substituent R is C5~C 30 The alkyl chain has the structural formula C m H 2m+1 , m is an integer between 5 and 30.

3. The method for preparing the oxygen ether bridged perylene imide derivative according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: dispersing monobromoperylene imide, an Ar unit connected with a hydroxyl group and a Lewis base in an organic solvent in proportion, heating to carry out a Williamson synthesis reaction, quenching the reaction, combining the organic phases after washing and extraction and drying them by rotation, and finally performing column chromatography separation to obtain the oxygen ether bridged perylene imide derivative.

4. The preparation method according to claim 3, characterized in that: The structural formula of the monobromoperylene diimide is shown in Formula II; In the formula, R is C5~C 30 of the alkyl chain.

5. The preparation method according to claim 3, characterized in that: The structural formula of the Ar unit connected with a hydroxyl group is shown in Formula III; Ar[OH] n (III)? In the formula, Ar is an aromatic ring group; n is 3 to 4.

6. The preparation method according to claim 3, characterized in that: The molar ratio of the monobromoperylene imide, the Ar unit connected with a hydroxyl group and potassium carbonate is 3-8:1:2-40.

7. The preparation method according to claim 3, characterized in that: The organic solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, DMSO and tetrahydrofuran.

8. The preparation method according to claim 3, characterized in that: The heating reaction temperature is room temperature to 200° C., and the reaction time is 5 to 96 hours.

9. Use of the oxygen ether bridged perylene imide derivative according to any one of claims 1 to 2 or the oxygen ether bridged perylene imide derivative prepared by the preparation method according to any one of claims 3 to 8 as an organic solar cell acceptor material.

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