Substituent group modified oxobenzene core non-condensed ring micromolecule, preparation method thereof and application of substituent group modified oxobenzene core non-condensed ring micromolecule to photoelectric device

Abstract

The invention discloses a substituent group modified oxobenzene core non-condensed ring small molecule, which has the following structural formula: # imgabs0 #, in the formula, R1 is a C1-C30 alkyl chain, X and Y are respectively and independently selected from one of F, Cl, CH3 and OCH3, and Z is selected from one of H, F, Cl and CH3. According to the invention, a substituent-modified oxo-benzene ring is taken as a core unit, an electron pi bridge and end group optimization are combined, the coplanarity of a skeleton is cooperatively adjusted by utilizing an expansion effect and an electron effect, the crystallinity and the electron mobility of the material are improved, controllable adjustment of spanning from a medium band gap to a low band gap is realized, and energy loss is inhibited. When the non-condensed ring micromolecule is applied to an organic solar cell, the overall synthesis steps can be effectively simplified, the yield is improved, the preparation cost is reduced, and the efficiency of an obtained cell device is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoelectric materials and devices, and specifically relates to a class of non-condensed ring small molecules with oxybenzene core modified by substituents, a preparation method thereof and application of photoelectric devices. Background Art

[0002] As energy shortage and environmental degradation become increasingly serious, it is necessary to actively seek and develop renewable green energy; solar energy, as one of the most promising renewable energy sources, has received widespread attention. Among them, organic solar cells (OSCs), as a new type of solar cell device, have the characteristics of flexibility, light weight, adjustable color, solution processing, large-area printing preparation, etc., and have great application potential in portable electronic devices, wearable devices, building integration, etc., and are a hot spot in the field of solar cell research. At present, the energy conversion efficiency (PCE) of organic solar cells has exceeded 20%, and has entered the ranks of large-scale applications.

[0003] The Y series of condensed ring small molecule receptors have excellent absorption coefficients and strong π-π stacking due to their unique A-DA'DA structure and the use of electron-deficient cores. They have a wide absorption range and efficient charge transport, which greatly improves the photovoltaic efficiency of the battery. Although condensed ring receptor small molecules have many advantages, their long synthesis steps, especially the Friedel-Crafts alkylation ring closure reaction, usually have certain substrate adaptability, which reduces the synthesis yield and increases the preparation cost. In order to simplify the synthesis route and reduce material costs, non-condensed ring electron acceptors (NREAs) came into being. Compared with condensed ring receptors, non-condensed ring small molecules that extend the main chain through carbon-carbon single bonds have a simpler synthesis route and can reduce material costs. At the same time, more flexible molecular structure adjustability makes it easier to control the optical band gap and molecular stacking of the material, which can promote the improvement of battery performance and increase the possibility of application of non-condensed ring small molecule materials.

[0004] However, in view of the rotatability of carbon-carbon single bonds, non-condensed ring small molecules usually show low planarity of the framework unit, weaken the intermolecular π-π stacking effect, have low crystallization performance, and are easy to form large-scale mixed phases with the donor polymer, which is not conducive to the transport of carriers. For this reason, atoms with strong electronegativity, such as F, O, S, N, etc., are often introduced when constructing the molecular structure to form intramolecular F...H, F...S, S...O, S...N and other non-covalent interactions to inhibit the rotation of single bonds, so as to construct a rigid coplanar structure, improve molecular stacking and charge transfer performance, and achieve the purpose of improving the photovoltaic performance of non-condensed ring OSCs. In addition to using intramolecular non-covalent conformation locks to maintain the coplanarity of the molecule, the use of large steric side chains can also inhibit the torsion of single bonds, achieve excellent conformational stability and thus obtain excellent molecular planarity, ensuring good charge transfer performance. However, the efficiency of most material devices based on non-condensed ring receptors is still below 17%, which is still far behind the photovoltaic performance (20%) of the current mainstream condensed ring receptor materials. Summary of the invention

[0005] The main purpose of the present invention is to address the problems and shortcomings of the prior art and provide a class of non-condensed ring small molecules with a substituent-modified oxybenzene core, which utilizes steric effect and electronic effect to synergistically regulate the coplanarity of the skeleton, improve the crystallinity and electron mobility of the material, and achieve controllable regulation of the transition from medium band gap to low band gap, and can adjust the energy level distribution, which is beneficial to suppress energy loss.

[0006] Another object of the present invention is to provide the application of the above-mentioned non-condensed ring small molecules in optoelectronic devices. By selecting suitable donor and acceptor materials for blending, binary or ternary devices are prepared and applied to organic solar cells, which can effectively simplify the synthesis steps, improve the yield, reduce the preparation cost, and significantly improve the efficiency of the resulting battery device.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A type of non-condensed ring small molecule with a substituent-modified oxybenzene core, the structural formula is shown in Formula 1:

[0009]

[0010] In the formula, R1 is C1-C 30 An alkyl chain, X and Y are independently selected from one of F, Cl, CH3, OCH3, and Z is selected from one of H, F, Cl, CH3, etc.

[0011] In the above scheme, the non-condensed ring small molecule receptor has an oxybenzene ring as the central unit and presents an axially symmetrical structure.

[0012] In the above scheme, the structural formula of the central unit of the oxybenzene ring modified by the X and Y substituents is specifically as shown in Formula 2:

[0013]

[0014] Further, the π bridge Ar is selected from the following electron donating structures:

[0015]

[0016] Wherein, R2 is selected from C1~C 30 One of the alkyl chains, alkoxy chains or alkylthio chains.

[0017] The above-mentioned method for preparing a non-condensed ring small molecule with a substituent-modified oxybenzene core comprises the following steps:

[0018] 1) Using dioxybenzene substituted at the para position by X and Y substituents as a raw material, a bromination reaction is carried out to generate compound 1, and then a demethylation reaction is carried out with boron tribromide and an alkylation reaction is carried out under alkaline conditions to prepare compound 2;

[0019] 2) Compound 2 and the aldehyde-modified Ar unit are subjected to a substitution reaction (bromine substitution) under a catalyst and alkaline conditions to obtain Compound 3;

[0020] 3) Under weak alkaline conditions, compound 3 and the IC terminal unit substituted by Z are dissolved in an organic solvent (chloroform, etc.), and a Knoevenagel condensation reaction is carried out. After pure crystallization, the final target product is obtained.

[0021] In the above scheme, the general formula of the dimethoxybenzene substituted in the para position by the X and Y substituents is shown in Formula 4;

[0022]

[0023] In the formula, X and Y are independently selected from one of F, Cl, CH3, and OCH3.

[0024] In the above scheme, the general formula of the compound 1 is shown in Formula 5;

[0025]

[0026] In the formula, X and Y are independently selected from one of F, Cl, CH3, and OCH3.

[0027] In the above scheme, the general formula of the compound 2 is shown in Formula 6;

[0028]

[0029] In the formula, X and Y are independently selected from one of F, Cl, CH3 and OCH3.

[0030] In the above scheme, the aldehyde group in the aldehyde-modified Ar unit is modified on the thiophene, furan or selenophene of the Ar unit, and the specific structural formula is shown in 7;

[0031]

[0032] In the above scheme, the general formula of the compound 3 is shown in Formula 8;

[0033]

[0034] In the above scheme, in the IC terminal unit substituted by Z, Ar' is selected from one of thiophene, benzene, and naphthalene, and Z is selected from one of H, F, Cl, and CH3. The specific structural formula is shown in Formula 9;

[0035]

[0036] In the above schemes, the reaction conditions are all anhydrous and oxygen-free conditions; the protective atmosphere can be an inert atmosphere such as nitrogen, argon, etc.

[0037] In the above scheme, the temperature used for the alkylation reaction in step 1) is 120-140° C. and the reaction time is 36-48 h.

[0038] In the above scheme, the temperature used for the substitution reaction in step 2) is 70-110° C., and the reaction time is 2-24 h.

[0039] In the above scheme, the target product recrystallization solvent can be selected from n-hexane, petroleum ether, tetrahydrofuran and other solvents.

[0040] In the above scheme, the base used in the alkaline conditions in step 1) and step 2) is potassium hydroxide, cesium carbonate, rubidium carbonate or potassium carbonate, and the pH value used in the substitution reaction is 8-12.

[0041] In the above scheme, the temperature used for the Knoevenagel condensation reaction is 60-70° C. and the time is 12-24 hours.

[0042] In the above scheme, the weak base in step 3) is pyridine, triethylamine, diethylamine or hexahydropyridine, the pH value used in the Knoevenagel condensation reaction is 8-10; the palladium catalyst is tetrakistriphenylphosphine palladium, tris(dibenzylideneacetone)dipalladium or [1,1'-bis(diphenylphosphino)ferrocene]palladium dichloride.

[0043] The substituent-modified oxybenzene core non-condensed ring small molecule prepared according to the above scheme is a medium band gap material (1.6-1.8 eV) or a low band gap material (1.2-1.6 eV, excluding 1.6 eV).

[0044] The present invention provides an application of the above-mentioned substituent-modified oxybenzene core non-condensed small molecule as an active layer material in a photoelectric device.

[0045] Furthermore, the substituent-modified oxybenzene core non-condensed ring small molecule is used as an acceptor material and blended with a wide-bandgap polymer material and a narrow-bandgap acceptor material to cover a wider light absorption range, ensuring that the film fully utilizes light, and the ternary organic solar cell prepared after blending can obtain a higher short-circuit current.

[0046] Specifically, the optoelectronic device is an organic solar cell, a perovskite solar cell, an organic light emitting diode or an organic detector.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1) The non-condensed ring small molecule of the present invention uses a substituent-modified oxybenzene ring as a core unit, the raw materials involved are cheap, the structure is simple, the substitution sites are multiple and easy to modify, and it is suitable for mass production;

[0049] 2) The present invention introduces substituents with different electronic capabilities on the oxybenzene ring that is easily modified at multiple sites, and combines the electron-donating π bridge and the end group optimization, and utilizes its extension effect and electronic effect to synergistically adjust the coplanarity of the skeleton, strengthen the charge transfer within the molecule, and improve the absorption spectrum of the molecule; at the same time, the energy level distribution of the molecule can be adjusted, the energy loss can be reduced, and the synergistic optimization of the battery device parameters can be achieved;

[0050] 3) The present invention can design different types of non-condensed ring molecules that span from medium band gap to low band gap as acceptor materials, and by blending with suitable donor-acceptor materials, binary or ternary devices covering different absorption bands can be prepared and applied to organic solar cells, thereby simplifying the synthesis steps, improving the yield, and reducing the cost while obtaining high-efficiency battery devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The UV-visible absorption spectra of PTBF-4Cl obtained in the present invention in chloroform solution (room temperature) and in thin film state.

[0052] Figure 2 The electrochemical cyclic voltammetry curve of PTBF-4Cl obtained in the present invention is shown in FIG.

[0053] Figure 3 The figure is a UV-visible absorption spectrum of a thin film of PTBF-4Cl obtained in the present invention, a polymer donor PM6 and a condensed ring acceptor L8-BO.

[0054] Figure 4The JV curve of the ternary organic solar cell prepared by blending the PTBF-4Cl obtained in the present invention with the polymer donor PM6 and the condensed ring acceptor L8-BO. DETAILED DESCRIPTION

[0055] The technical solutions adopted in the present invention are described in detail below through specific implementation examples, which are only part of the present invention and do not represent all embodiments. Unless otherwise specified, the experimental methods adopted in the present invention are all conventional methods, and the instruments and equipment adopted are all commercial products in the field of this technology.

[0056] In the following examples, the synthesis route of the compound 3-(4-hexylphenyl)thiophene-2-carboxaldehyde is shown in Formula 10:

[0057]

[0058] The specific preparation steps are as follows:

[0059] Under a nitrogen atmosphere, 1-bromo-4-hexylbenzene (1.21 g, 5 mmol), tetrakis(triphenylphosphine)palladium (57.78 mg, 50 μmol), and potassium carbonate (4.02 g, 29 mmol) were added to a double-necked flask, and 45 mL of a mixed solvent of toluene, ethanol, and water (the volume ratio of toluene, ethanol, and water was 20:5:1) was prepared to dissolve the solid; subsequently, 3-thiopheneboric acid (767.71 g, 6 mmol) was added, the reaction temperature was raised to reflux, and the reaction was vigorously stirred for 48 h. After the reaction was completed, it was cooled to room temperature, extracted with 100 mL of ethyl acetate three times, the organic layer was collected and extracted with brine and deionized water, dried over anhydrous sodium sulfate, the solvent was removed by rotation, and column chromatography was performed using petroleum ether as an eluent to obtain a white solid. Subsequently, the obtained white solid (0.24 g, 1 mmol) and anhydrous DMF (73.1 mg, 1 mmol) were mixed, cooled to 0°C, phosphorus oxychloride (659.29 mg, 4.3 mmol) was added, stirred for 1 h, and then the obtained solution was slowly added dropwise to 1,2-dichloroethane, and continued to stir at 0°C for 20 min, then heated to 80°C and stirred for 4 h; after the reaction was completed, cooled to room temperature to obtain 3-(4-hexylphenyl)thiophene-2-carboxaldehyde (0.23 g, 87%); 1 H NMR (400MHz, CDCl3) δ (ppm): 9.89 (s, 1H), 7.72 (d, J = 4.0Hz, 1H), 7.39 (d, J = 8.0Hz, 2H), 7.29 (d, J = 8.0 Hz, 2H), 7.22 (d, J = 4.0Hz, 1H), 2.67 (d, J = 8.0Hz, 2H), 1.66 (m, 2H), 1.33 (m, 6H), 0.89 (t, J = 7.5Hz, 3H).

[0060] Example 1

[0061] A non-condensed ring small molecule (PTBF-4Cl) with a difluoro-substituted oxybenzene ring as the core, the synthesis route of which is shown in Formula 11:

[0062]

[0063] The specific preparation steps are as follows:

[0064] 1) Under nitrogen atmosphere, 1,4-difluoro-2,5-dimethoxybenzene (2.26 g, 13 mmol) was dissolved in 36 mL of chloroform, and 6.66 mL of Br2 was slowly and uniformly added. After the addition was complete, the mixture was stirred at room temperature overnight. After the reaction was completed, the mixture was quenched with deionized water, and a saturated sodium hydroxide solution was added dropwise to treat the excess Br2 and hydrobromic acid, followed by extraction with dichloromethane (DCM); the organic phase was collected, dried over anhydrous sodium sulfate, and the solvent was removed by spinning. The crude product was subjected to column chromatography using a mixed solvent of petroleum ether and dichloromethane (the volume ratio of the two was 1:1) as an eluent to obtain a white solid compound 1 (3.81 g, 89.3%); 1 H NMR (400MHz, CDCl3) δ (ppm): 3.95 (s, 6H);

[0065] 2) Under nitrogen atmosphere, compound 1 (0.66 g, 2 mmol) was dissolved in 8 mL of dichloromethane, and boron tribromide (3.01 g, 12 mmol) was slowly and uniformly added, followed by heating to 50 ° C for 24 h; the obtained product was poured into deionized water, extracted with ethyl acetate, the organic layer was collected, dried over anhydrous sodium sulfate, and the solvent was removed by spinning, and the intermediate product was directly used in the next step without purification; then, under nitrogen atmosphere, the obtained intermediate product and cesium carbonate (3.26 g, 10 mmol) were dissolved in 5 mL of DMF, 1-bromo-2-octyldodecane (1.81 g, 5 mmol) was added, and the temperature was raised to 120 ° C for 48 h, the obtained product was poured into deionized water, extracted with dichloromethane, dried over anhydrous sodium sulfate, the solvent was removed by spinning, and the crude product was subjected to column chromatography with pure solvent petroleum ether to obtain colorless oily compound 2 (0.93 g, 54%); 1 H NMR (400MHz, CDCl3) δ (ppm): 3.95 (d, J = 5.28Hz, 4H), 1.76 (m, 2H), 1.27 (m, 64H), 0.88 (t, J = 6.62Hz, 12H);

[0066] 3) Under nitrogen atmosphere, compound 2 (0.69 g, 0.8 mmol), 3-(4-hexylphenyl)thiophene-2-carboxaldehyde (0.54 g, 2 mmol), cesium carbonate (0.78 g, 2.4 mmol), pivalic acid (32.68 mg, 0.32 mmol), tris(dibenzylideneacetone)dipalladium (18.31 mg, 0.02 mmol), tris(o-methoxyphenyl)phosphine (14.22 mg, 0.04 mmol) were added to a double-necked flask in sequence, and 10 mL of toluene was added. After stirring and dissolving, the mixture was heated to 110 ° C. and reacted for 2 h. Deionized water was added to quench the reaction, extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotation. A mixed solvent of petroleum ether and dichloromethane (the volume ratio of petroleum ether to dichloromethane was 1:2) was used as the eluent for column chromatography purification to obtain compound 3 (0.82 g, 82%); 1 H NMR (400MHz, CDCl3) δ (ppm): 9.98 (s, 2H), 7.67 (s, 2H), 7.45 (d, J = 7.96Hz, 4H), 7.34 (d, J = 7.96Hz, 4H), 3. 93(d,J=5.64Hz,4H), 2.71(t,J=7.76Hz,4H),1.69(m,2H),1.58(m,4H),1.23-1.35(m,76H),0.89(m,18H);

[0067] 4) Under nitrogen atmosphere, compound 3 (0.20 g, 0.16 mmol) and chloro-substituted IC end group (0.17 g, 0.63 mmol) were added to a double-necked flask and dissolved in 5 mL of a mixed solution of chloroform and pyridine (the volume ratio of chloroform to pyridine was 40:1), and the temperature was raised to 60 ° C for reaction for 24 h. After the reaction, the solution was cooled and concentrated, and a mixed solvent of petroleum ether and dichloromethane (the volume ratio of the two was 1:1) was selected for column chromatography purification, and further pure crystallization was performed with n-hexane to obtain the target molecule PTBF-4Cl (0.24 g, 87%); 1 H NMR (400MHz, CDCl3) δ (ppm): 8.76 (s, 4H), 7.97 (s, 2H), 7.83 (s, 2H), 7.36 (s, 8H), 4.00 (d, J = 6Hz 4H), 2.72 (t, J = 7.74Hz, 4H), 1.96 (m, 2H), 1.69 (m, 4H), 1.17-1.35 (m, 76H), 0.92 (t, J = 6.96Hz, 6H), 0.85 (m, 12H).

[0068] Figure 1 The UV-visible absorption spectra of PTBF-4Cl obtained in the present invention in chloroform solution (room temperature) and thin film state, wherein the solution concentration is 1×10 -5The steps of preparing the film are as follows: dissolving the target molecule PTBF-4Cl in chloroform to prepare a solution with a concentration of 10 mg / mL, and then using a spin coater to prepare a film with a thickness of 30 to 100 nm. Figure 1 As shown, in the solution state, PTBF-4Cl shows a strong absorption peak in the range of 470 to 650nm. In contrast, the target molecule PTBF-4Cl in the film state exhibits two main absorption peaks. In addition to the main absorption peak at 593nm, a new absorption peak is added at 630nm and the intensity is close to the main peak, indicating that PTBF-4Cl has a strong aggregation ability in the film state. At the same time, compared with the solution, the film absorption peak is red-shifted by 30nm, and the absorption range is expanded, indicating that the formed film structure has stronger π-π stacking, which is conducive to obtaining high carrier mobility. In addition, the edge absorption of the PTBF-4Cl film is at 695nm. According to the band gap formula E g =1240 / λ, we can get: E g The band gap is 1.78 eV, which is a small molecule with a medium band gap, which is mainly due to the synergistic effect of core fluorine-substituted electrons and steric hindrance.

[0069] The redox process of PTBF-4Cl was tested by electrochemical cyclic voltammetry. Ferrocene was used as a reference (vacuum level was -4.8 eV) to obtain the initial redox potential corresponding to the target molecule. The highest occupied molecular orbital energy level (HOMO) and the lowest occupied molecular orbital energy level (LUMO) of the material were obtained according to the formula: E HOMO =-(E ox onset -E Fc / Fc+ +4.8) eV and E LUMO =-(E red onset -E Fc / Fc+ +4.8)eV. Using a three-electrode system, PTBF-4Cl was prepared into a chloroform solution with a concentration of 5mg / mL, and then dripped onto a glassy carbon electrode to prepare a thin film. The glassy carbon electrode with the prepared film was then placed in an acetonitrile electrolyte solution containing 0.1M tetrabutylammonium hexafluorophosphate for testing. The entire testing process required nitrogen protection. Figure 2 As shown: the standard electrode potential of ferrocene is 0.04V, and PTBF-4Cl has an irreversible redox process, and the corresponding initial oxidation potential and reduction potential are 1.44V and -0.82V, respectively. According to the above formula, the HOMO and LUMO energy levels of PTBF-4Cl can be calculated to be -6.20eV and -3.94eV, respectively. The deeper HOMO energy level of this molecule can be combined with different types of donor materials to prepare efficient battery devices.

[0070] The polymer material PM6 with a medium band gap (structural formula shown in Formula 12, molecular weight 30-65 kDa) and the receptor material L8-BO with a narrow band gap (structural formula shown in Formula 13) are selected to be blended with the non-condensed ring receptor small molecule of the present invention, which can cover a wide absorption range from 400 to 900 nm (see Figure 3 ), ensuring that the film fully utilizes light, the prepared ternary organic solar cell can obtain a higher short-circuit current.

[0071]

[0072]

[0073] Based on the above discussion on the light absorption and energy level of the target molecule, PTBF-4Cl was added as the third component to the PM6:L8-BO mixed film to prepare a dual-acceptor ternary organic solar cell. The photovoltaic performance of the cell was tested using the forward device structure: ITO / PEDOT:PSS / PBTTzE:PTBF-4Cl:L8-BO / PDIN / Ag. When the mass ratio of PM6:L8-BO:PTBF-4Cl was 1:1.2:0.15, the optimal cell device (see Figure 4 ) reaches 18.55%, among which V oc 0.87V, J sc The absorption rate is 26.98 mA / cm and the FF is 79.03%. Compared with the binary device of PM6:L8-BO, the ternary device with PTBF-4Cl added has enhanced the capture ability of photons in the range of 620-680 nm and increased the absorption intensity, thus obtaining a higher J sc .

[0074] Example 2

[0075] A non-condensed ring small molecule (PhO-CPDT-4Cl) with a dimethoxy-substituted oxybenzene ring as the core, the synthesis route of which is shown in

[0076] Formula 14:

[0077]

[0078] The specific preparation steps are as follows:

[0079] 1) Under nitrogen atmosphere, 1,4-difluoro-2,5-dimethoxybenzene (0.35 g, 2 mmol) was dissolved in 8 mL of dichloromethane, and boron tribromide (3.01 g, 12 mmol) was slowly and uniformly added, and then the temperature was raised to 50 ° C for reaction for 24 h; the obtained product was poured into deionized water, extracted with ethyl acetate, the organic layer was collected, dried over anhydrous sodium sulfate, and the solvent was removed by rotation, and the intermediate product was directly used in the next step without purification; then, under nitrogen atmosphere, the obtained intermediate product and cesium carbonate (3.26 g, 10 mmol) were dissolved in 5 mL of DMF, 1-bromo-2-butyloctane (1.25 g, 5 mmol) was added, and the temperature was raised to 120 ° C for reaction for 48 h, the obtained product was poured into deionized water, extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotation, and the crude product was subjected to column chromatography with pure solvent petroleum ether to obtain colorless oily compound 1 (0.63 g, 65%); 1 H NMR (400MHz, CDCl3) δ6.75 (s, 2H), 3.82 (d, J = 5.7Hz, 4H), 1.77 (m, 2H), 1.29 (m, 32H), 0.89 (t, J = 6.62Hz, 12H);

[0080] 2) Under nitrogen atmosphere, compound 1 (0.48 g, 1 mmol) and sodium hydride (0.28 g, 12 mmol) were dissolved in 10 mL DMF, the reaction temperature was controlled to 0°C, and methanol (0.64 g, 20 mmol) was added; the temperature was then raised to 100°C and refluxed, and stirred for 24 h; the resulting product was poured into deionized water, extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed by rotation. A mixed solvent of petroleum ether and dichloromethane (the volume ratio of petroleum ether to dichloromethane was 3:1) was used as the eluent for column chromatography purification to obtain a light yellow oily compound 2 (0.37 g, 75%); 1 H NMR (500MHz, CDCl3) δ6.61 (s, 2H), 3.85 (s, 4H), 3.83 (s, 6H), 1.81 (d, J = 11.6Hz, 2H), 1.34 (s, 32H), 0.91 (s, 12H);

[0081] 3) Under nitrogen atmosphere, compound 2 (0.34 g, 0.7 mmol) was dissolved in 3 mL of chloroform, and 0.67 g of Br2 was slowly and uniformly added. After the addition was complete, the mixture was stirred at room temperature for 4 h. After the reaction was completed, the mixture was quenched with deionized water, and a saturated sodium hydroxide solution was added dropwise to treat the excess Br2, followed by extraction with petroleum ether. The organic phase was collected, dried over anhydrous sodium sulfate, and the solvent was removed by spinning. A mixed solvent of petroleum ether and dichloromethane (the volume ratio of petroleum ether to dichloromethane was 1:1) was used as the eluent for column chromatography purification to obtain a light yellow oily compound 3 (0.41 g, 89%). 1H NMR (500MHz, CDCl3) 3.85 (s, 4H), 3.83 (s, 6H), 1.81 (d, J = 11.6Hz, 2H), 1.34 (s, 32H), 0.91 (s, 12H);

[0082] 4) Under nitrogen atmosphere, compound 3 (0.5 g, 0.78 mmol), cyclopentadithiophene tin salt (1.49 g, 2.34 mmol), tetrakistriphenylphosphine palladium (0.04 g, 0.03 mmol) were dissolved in 4 mL of DMF solution, and then the temperature was raised to 110 ° C. for reaction for 7 h. After the reaction was completed, deionized water was quenched, and then extracted with dichloromethane; the organic phase was collected and washed with a large amount of deionized water, dried over anhydrous sodium sulfate, and the solvent was removed by rotation. Pure petroleum ether was used as the eluent for column chromatography purification to obtain a light yellow compound 4 (0.42 g, 44%); 1 H NMR (400MHz, CDCl3) δ7.46 (s, 2H), 7.17 (d, J = 4.8Hz, 2H), 6.95 (d, J = 5.6Hz, 2H), 3.83 (s, 4H), 3. 82(s,6H),1.91(s,14H),1.30(s,32H),0.95(s,32H),0.89(s,12H),0.76(s,12H),0.61(s,12H);

[0083] 5) Under nitrogen atmosphere, compound 4 (0.41 g, 0.34 mmol) and anhydrous DMF (0.62 g, 0.85 mmol) were mixed, cooled to 0°C, phosphorus oxychloride (0.22 g, 1.46 mmol) was added dropwise, stirred for 1 h, and the resulting solution was slowly added dropwise to 1,2-dichloroethane (10 mL), followed by continued stirring at 0°C for 20 min, then heated to 80°C and stirred for 4 h; after the reaction was completed, quenched with saturated sodium hydroxide, and then extracted with dichloromethane; the organic phase was collected and dried over anhydrous sodium sulfate, the solvent was removed by rotation, and a mixed solvent of petroleum ether and dichloromethane (the volume ratio of petroleum ether to dichloromethane was 1:1) was selected as the eluent for column chromatography purification to obtain a light yellow compound 5 (0.22 g, 50%). 1 H NMR (400MHz, CDCl3) δ9.85(s,2H),7.59(s,2H),7.52(s,2H),3.86(s,4H),3.83(s,6H),1.97(s,8H),1.69 -1.58(m,6H),1.26(s,32H),1.04-0.90(m,32H),0.85(s,12H),0.74(s,12H),0.61(s,12H);

[0084] 6) Under nitrogen, compound 5 (0.12 g, 0.1 mmol) and chloro-IC end group (0.11 g, 0.45 mmol) were added to a two-necked flask and dissolved in 15 mL of chloroform. 1 mL of pyridine solution was then added dropwise and the temperature was raised to 60 ° C for 4 h. After the reaction, the solution was cooled and concentrated, and a mixed solvent of petroleum ether and dichloromethane (the volume ratio of the two was 1:1) was used for column chromatography purification, and further pure crystallization was performed with n-hexane to obtain the target molecule PhO-CPDT-4Cl (0.1 g, 50%); 1 HNMR(400MHz, CDCl3)δ8.95(s,2H),8.75(s,2H),7.92(s,2H),7.59(s,2H),7.52(s,2H),3.86(s,4H),3.83 (s,6H),1.97(s,8H),1.63(m,6H),1.26(s,32H),0.98(m,32H),0.85(s,12H),0.74(s,12H),0.61(s,12H).

[0085] After testing, the E of the non-condensed ring small molecule (PhO-CPDT-4Cl) obtained by the present invention is g It is 1.42eV, which is a low band gap small molecule.

[0086] Example 3

[0087] A non-condensed ring small molecule (PhF-CPDT-4Cl) with a difluoro-substituted oxybenzene ring as the core and cyclopentadithiophene as a π bridge, the synthesis route of which is shown in Formula 15:

[0088]

[0089] The specific preparation steps are as follows:

[0090] 1) Under nitrogen atmosphere, 1,4-dibromo-2,5-bis(2-butyloctyloxy)-3,6-difluorobenzene (0.64 g, 1.00 mmol), cyclopentadithiophene tin salt (1.91 g, 3.00 mmol), and tetrakistriphenylphosphine palladium (0.05 g, 0.05 mmol) were dissolved in 4 mL DMF solution, and then the temperature was raised to 110 ° C. for reaction for 7 h. After the reaction was completed, deionized water was quenched, and then extracted with dichloromethane; the organic phase was collected and washed with a large amount of deionized water, dried over anhydrous sodium sulfate, and the solvent was removed by rotation. Pure petroleum ether was used as the eluent for column chromatography purification to obtain a light yellow compound 1 (0.42 g, 39%); 1H NMR (400MHz, CDCl3) δ7.46(s,2H),7.17(d,J=4.8Hz,2H),6.95(d,J=5.6Hz,2H),3.83(s,4 H),1.91(s,14H),1.30(s,32H),0.95(s,32H),0.89(s,12H),0.76(s,12H),0.61(s,12H);

[0091] 2) Under nitrogen atmosphere, compound 1 (0.63 g, 0.52 mmol) and anhydrous DMF (0.10 g, 1.3 mmol) were mixed, cooled to 0°C, phosphorus oxychloride (0.34 g, 2.24 mmol) was added dropwise, stirred for 1 h, and then the resulting solution was slowly added dropwise to 1,2-dichloroethane (15 mL), followed by continued stirring at 0°C for 20 min, then heated to 80°C, stirred for 4 h, and after the reaction was completed, quenched with saturated sodium hydroxide, and then extracted with dichloromethane; the organic phase was collected and dried over anhydrous sodium sulfate, the solvent was removed by rotation, and a mixed solvent of petroleum ether and dichloromethane (the volume ratio of petroleum ether to dichloromethane was 1:1) was selected as the eluent for column chromatography purification to obtain a light yellow compound 2 (0.22 g, 33%); 1 H NMR(400MHz, CDCl3)δ9.85(s,2H),7.59(s,2H),7.52(s,2H),3.86(s,4H),1.97(s,8H),1.69 -1.58(m,6H),1.26(s,32H),1.04-0.90(m,32H),0.85(s,12H),0.74(s,12H),0.61(s,12H);

[0092] 3) Under nitrogen, compound 2 (0.25 g, 0.2 mmol) and chloro-IC end group (0.23 g, 0.9 mmol) were added to a two-necked flask and dissolved in 15 mL of chloroform. 1 mL of pyridine solution was then added dropwise and the temperature was raised to 60 ° C for 4 h. After the reaction, the solution was cooled and concentrated, and a mixed solvent of petroleum ether and dichloromethane (the volume ratio of the two was 1:1) was used for column chromatography purification, and further pure crystallization was performed with n-hexane to obtain the target molecule PhF-CPDT-4Cl (0.19 g, 54%); 1 HNMR(400MHz, CDCl3)δ8.95(s,2H),8.75(s,2H),7.92(s,2H),7.59(s,2H),7.52(s,2H),3.86(s,4H ),1.97(s,8H),1.63(m,6H),1.26(s,32H),0.98(m,32H),0.85(s,12H),0.74(s,12H),0.61(s,12H).

[0093] After testing, the E of the non-condensed ring small molecule (PhF-CPDT-4Cl) obtained by the present invention is g It is 1.51eV, which is a low band gap small molecule.

[0094] The present invention takes simple-structured oxybenzene as the core, utilizes molecular engineering means, introduces substituent groups with different electronic capabilities on the easily modifiable benzene ring at multiple sites, utilizes steric effect and electronic effect to synergistically adjust the coplanarity of the skeleton, and assists with π bridge and end group optimization to adjust the light absorption capacity and energy level distribution, thereby preparing different types of non-condensed ring receptor molecules spanning from medium band gap to low band gap, which can be used as active layer materials or third components in organic optoelectronic devices to obtain higher device conversion efficiency.

[0095] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A class of non-condensed ring small molecules with substituent-modified oxybenzene core, characterized in that: Its structural formula is shown in Formula 1: In the formula, R1 is C1-C 30 An alkyl chain, X and Y are independently selected from one of F, Cl, CH3, and OCH3, and Z is selected from one of H, F, Cl, and CH3.

2. The non-condensed ring small molecule according to claim 1, characterized in that: The structural formula of the oxybenzene ring central unit modified by the X and Y substituents is specifically as shown in Formula 2:

3. The non-condensed ring small molecule according to claim 1, characterized in that: The π-bridge Ar is selected from the following electron-donating structures: Wherein, R2 is selected from C1~C 30 One of the alkyl chain, alkoxy chain and alkylthio chain.

4. The method for preparing the non-condensed ring small molecule with a substituent-modified oxybenzene core as claimed in claim 1, characterized in that: The steps include: 1) Using dimethoxybenzene substituted at the para position with X and Y substituents as a raw material, a bromination reaction is carried out to generate compound 1, and then a demethylation reaction is carried out with boron tribromide and an alkylation reaction is carried out under alkaline conditions to prepare compound 2; 2) Compound 2 and the aldehyde-modified Ar unit are subjected to a substitution reaction (bromine substitution) under a catalyst and alkaline conditions to obtain Compound 3; 3) Under weak alkaline conditions, compound 3 and the IC terminal unit substituted by Z are dissolved in an organic solvent, and a Knoevenagel condensation reaction is carried out. After pure crystallization, the final target product is obtained.

5. The preparation method according to claim 4, characterized in that: The general formula of the dimethoxybenzene substituted in the para position by the X and Y substituents is shown in Formula 4; the general formula of compound 1 is shown in Formula 5; In the formula, X and Y are independently selected from one of F, Cl, CH3, and OCH3.

6. The preparation method according to claim 4, characterized in that: The general formula of compound 2 is shown in Formula 6; In the formula, X and Y are independently selected from one of F, Cl, CH3, and OCH3.

7. The preparation method according to claim 4, characterized in that: In the aldehyde-modified Ar unit, the aldehyde group is modified on the thiophene, furan or selenophene of the Ar unit, and the structural formula is shown in 7; 8. The preparation method according to claim 4, characterized in that: The general formula of compound 3 is shown in Formula 8; 9. The preparation method according to claim 4, characterized in that: In the Z-substituted IC terminal unit, Ar' is selected from one of thiophene, benzene, and naphthalene, and Z is selected from one of H, F, Cl, and CH3. The structural formula of the unit is shown in Formula 9; 10. Use of the substituent-modified oxybenzene core non-condensed ring small molecule obtained according to any one of claims 1 to 3 or the substituent-modified oxybenzene core non-condensed ring small molecule obtained according to the preparation method of any one of claims 4 to 9 as an active layer material in optoelectronic devices.

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