Non-planar cyclic compound with intramolecular space coupling effect and synthesis method of non-planar cyclic compound
By designing non-planar cyclic compounds with spatial coupling intramolecular systems, the problems of high difficulty in synthesis of low band gap organic molecules and insufficient performance of non-planar cyclic molecules are solved, and photoelectric materials with high yield and high efficiency near-infrared response are achieved.
Patent Information
- Application Number
- CN202510440729.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-11
AI Technical Summary
In the prior art, the synthesis of low-bandgap organic molecular materials is difficult to achieve near-infrared absorption and high-efficiency carrier transmission of low band gap organic molecular materials, which limits their performance in optoelectronic devices.
By introducing intramolecular spatial coupling, D-π-A-π-D non-planar cyclic conjugated structures with trianiline units as electron donors, 4,4-bis(2-ethylhexyl)-dithiopheneocyclopentadiene as π bridges, benzothiadiazole or its derivatives as electron acceptors are designed to assist in the stability of the conjugated skeleton, limit the torsion between the conjugated units, and achieve high yield and near-infrared response.
It improves π electron delocalization and energy level regulation, reduces band gap, enhances light absorption capacity and carrier transmission performance, and improves the processability and photoelectric performance of the material.
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Figure CN120289491A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of organic semiconductor materials, and particularly to a non-planar cyclic compound with intramolecular space coupling effect and a synthesis method thereof. Background Art
[0002] The preparation of organic low-bandgap molecules capable of realizing near-infrared (NIR) luminescence or optoelectronic response is a research hotspot in the fields of organic electronics, optoelectronics, and biological imaging. Such molecules usually need to have an extended π-conjugated system, intramolecular charge transfer (ICT) characteristics, or a specific energy level structure to achieve a narrow bandgap (usually <1.5 eV) and efficient near-infrared absorption / emission.
[0003] In the design and development process of near-infrared (NIR)-active organic molecules, researchers have proposed various strategies through multi-dimensional cooperative regulation strategies, from simple conjugated systems in the early stage to complex multi-functional molecular architectures today: (1) Extension and strengthening of the conjugated backbone: By increasing linear conjugated units (such as acene compounds) or constructing a three-dimensional conjugated network (such as spiro molecules), the π→π* transition energy level can be effectively reduced; (2) Stabilization engineering of the quinoid structure: Developing a reversible quinoid-aromatic equilibrium system (such as diketopyrrolopyrrole compounds) can significantly reduce the bond length alternation (BLA) value; (3) Strengthening and expansion of molecular planarity: By introducing double bonds, triple bonds, rigid fused rings (such as thiophene[3,2-b]thiophene) or designing a cyclic cross-conjugated system to suppress torsional distortion and ensure maximum π-electron delocalization; (4) Directional enhancement of the charge transfer effect: Constructing a D-A-D or A-D-A type donor-acceptor topological structure and using orbital hybridization between donor and acceptor units to regulate the charge separation state; (5) Strategic introduction of the heavy atom effect: Selectively incorporating heteroatoms such as sulfur, selenium, and tellurium, and promoting intersystem crossing through spin-orbit coupling can effectively extend the absorption spectrum to the second near-infrared region (NIR-II); (6) Cooperative utilization of intermolecular interactions: Carefully designing modified groups or side chain structures to induce other self-assembly behaviors such as J-aggregation and H-aggregation between molecules, and realizing the red shift of the absorption and emission spectra in the thin film state. The iterative innovation of these multi-dimensional regulation means has gradually extended the absorption / emission boundary of organic near-infrared materials from the initial visible light region to the near-infrared region, providing multiple innovative paths for the fields of organic optoelectronics and biomedical imaging.
[0004] Currently, most low-bandgap organic molecules are fused heteroaromatic super-large π-conjugated systems. However, the construction of such structures often involves harsh reaction conditions (such as high temperature and high pressure, inert atmosphere protection), inefficient ring-closure steps (such as Scholl reaction, etc.), and cumbersome purification processes, resulting in a low total yield (usually <30%), and may be accompanied by problems such as many by-products and high solvent toxicity, seriously restricting the large-scale preparation and practical application of the materials.
[0005] On the other hand, easily accessible non-planar cyclic molecules are difficult to achieve near-infrared absorption due to the lack of long-range conjugated chains or broad conjugated planes, and the light absorption coefficient of the materials will also be severely restricted. On the other hand, their flexible molecular conformations make it difficult to achieve tight π-π stacking when in the thin film state, which will limit the carrier transport rate of their thin films, resulting in poor performance of optoelectronic devices prepared based on such materials. Summary of the Invention
[0006] The object of the present invention is to provide a non-planar cyclic compound containing intramolecular space coupling and its synthesis method. By introducing intramolecular space coupling, the modification difficulty of low-bandgap molecules is reduced and the yield is increased. At the same time, the non-planar cyclic conjugated molecules obtain near-infrared response and high hole transport ability, solving the problems in the background technology.
[0007] To achieve the above object, the present invention provides a non-planar cyclic compound containing intramolecular space coupling. The non-planar cyclic compound has a D-π-A-π-D push-pull electron non-planar cyclic conjugated structure with a triphenylamine unit as the electron donor, 4,4-bis(2-ethylhexyl)-dithieno[3,2-b:2',3'-d]cyclopentadiene (CPDT) as the π-bridge, and benzothiadiazole or its derivative as the electron acceptor.
[0008] The present invention also provides a synthesis method of the above non-planar cyclic compound containing intramolecular space coupling, specifically including the following steps:
[0009] S1. Under a nitrogen atmosphere, compound 1 (CPDT) and N-bromosuccinimide are dissolved in anhydrous dichloromethane and stirred at room temperature for 8 h. After extracting the organic substances, they are washed and dried, and the crude product compound 2 is obtained by concentration. The structural formulas of compound 1 and compound 2 are as follows:
[0010]
[0011] S2. Compound 2, 4,4'-dimethoxy-4''-boronic acid triphenylamine, Pd[P(C6H5)3]4 and K2CO3 are dissolved in a dioxane solution and mixed. The mixture is degassed with nitrogen for 15 min and then refluxed and stirred for 12 h. After cooling to room temperature, the organic substances are extracted and dried, and column chromatography purification is carried out on silica gel using a mixed solvent of dichloromethane / petroleum ether as the eluent to obtain a brown solid compound 3. The structural formula of compound 3 is as follows:
[0012]
[0013] S3. Dissolve compound 3 in tetrahydrofuran, add n-butyllithium under a nitrogen atmosphere at -78 °C and stir for 1 h, then add trimethyltin chloride, and then stir at room temperature for 8 - 12 h. Quench the reaction with water, extract the organic matter, wash and dry it, and concentrate it under reduced pressure to obtain the crude product compound 4; The structural formula of compound 4 is as follows:
[0014]
[0015] S4. Dissolve compound 4, benzothiadiazole or benzothiadiazole derivative in toluene, degas the mixture with nitrogen for 15 min, then add (PPh3)2PdCl2 and reflux for 6 - 24 h. After cooling to room temperature, extract the organic matter, wash and dry it, remove the solvent under reduced pressure, and use a mixed solvent of dichloromethane / petroleum ether as the eluent to purify the product by silica gel column chromatography to obtain the black solid as the final product.
[0016] Preferably, in step S1, the molar ratio of compound 1 to N-bromosuccinimide is 1 - 1.4:1.
[0017] Preferably, in step S1, extract with deionized water, wash with saturated brine, and dry with anhydrous sodium sulfate.
[0018] Preferably, in step S2, the molar ratio of compound 2, 4,4'-dimethoxy-4”-triphenylamine boronic acid, Pd[P(C6H5)3]4, and K2CO3 is 1:1.2 - 3:0.05 - 0.3:3 - 5, and the volume ratio of dichloromethane to petroleum ether in the mixed solvent of dichloromethane / petroleum ether is 2:1.
[0019] Preferably, in step S2, extract with petroleum ether and dry with anhydrous sodium sulfate.
[0020] Preferably, in step S3, the molar ratio of compound 3, n-butyllithium, and trimethyltin chloride is 1:1 - 3:1 - 2.
[0021] Preferably, in step S3, extract with petroleum ether, wash with deionized water, and dry with anhydrous sodium sulfate.
[0022] Preferably, in step S4, the molar ratio of compound 4, benzothiadiazole or benzothiadiazole derivative, and (PPh3)2PdCl2 is 2 - 4:1:0.05 - 0.3, and the volume ratio of dichloromethane to petroleum ether in the mixed solvent of dichloromethane / petroleum ether is 2:1.
[0023] Preferably, in step S4, extract with dichloromethane, wash with saturated brine, and dry with anhydrous MgSO4.
[0024] The present invention introduces multiple intramolecular spatial coupling effects in non-planar cyclic molecules, which are synergistically regulated by non-covalent conformational locking and steric hindrance, to assist in stabilizing the conjugated backbone of non-planar cyclic molecules, restricting the torsional dihedral angle between conjugated units to maintain the planarity of the molecule. While obtaining low-bandgap molecules in high yields, the light absorption ability and carrier transport ability are maintained, and the processability of the material is potentially improved by weakening the molecular rigidity. This molecule has the potential to be used as a photoactive material and a hole transport material.
[0025] Therefore, a non-planar cyclic compound containing intramolecular spatial coupling effects and a synthesis method thereof provided by the present invention have the following beneficial effects:
[0026] (1) Enhancing π-electron delocalization and energy level regulation
[0027] Reducing the bandgap: By assisting the rigid planar structure to maximize π-electron conjugation, the HOMO-LUMO energy gap is significantly reduced, and the absorption / emission is extended to the near-infrared region.
[0028] (2) Improving charge transport performance
[0029] Mobility optimization: Planarization reduces the carrier hopping barrier; Anisotropic conduction: Locking a specific planar conformation can induce preferred orientation of molecules (such as edge-on arrangement) to achieve directional charge transport.
[0030] The technical solutions of the present invention will be further described in detail below with reference to the drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 Schematic diagram of the π-A-π backbone of TM-1, TM-2, and TM-3 molecules prepared in Examples 1-3 of the present invention;
[0032] Figure 2 Optical absorption spectrum of TM-2 molecule prepared in Example 2 of the present invention;
[0033] Figure 3 Statistical chart of the average hole mobility of TM-1, TM-2, and TM-3 molecules prepared in Examples 1-3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0034] The present invention provides a non-planar cyclic compound containing intramolecular spatial coupling effects. The non-planar cyclic compound has a D-π-A-π-D push-pull electron non-planar cyclic conjugated structure with a triphenylamine unit as an electron donor, 4,4-bis(2-ethylhexyl)-dithieno[3,2-b:2',3'-d]cyclopentadiene as a π-bridge, and benzothiadiazole or its derivative as an electron acceptor.
[0035] The present invention also provides a method for synthesizing the above non-planar cyclic compound with intramolecular space coupling effect:
[0036] (1) When using benzothiadiazole as the electron acceptor, the method includes the following steps:
[0037] S1. Under a nitrogen atmosphere, dissolve compound 1 (CPDT) and N-bromosuccinimide in anhydrous dichloromethane and stir at room temperature for 8 h. Extract the organic matter with water, wash it with saturated brine, and dry it with anhydrous sodium sulfate (Na2SO4), then concentrate to obtain the crude product of compound 2, which is directly used for the next step without further purification.
[0038]
[0039] In the present invention, the molar ratio of compound 1 to N-bromosuccinimide is 1 - 1.4:1.
[0040] S2. Dissolve compound 2, 4,4'-dimethoxy-4''-boronic acid triphenylamine, Pd[P(C6H5)3]4 and K2CO3 in dioxane solution. Degas the mixture with nitrogen for 15 min and then reflux and stir for 12 h. After cooling to room temperature, extract the mixture with petroleum ether, and dry the organic layer over Na2SO4. Use a mixed solvent of dichloromethane / petroleum ether with a volume ratio of 2:1 as the eluent and perform column chromatography purification on silica gel to obtain the brown solid compound 3.
[0041]
[0042] In the present invention, the molar ratio of compound 2, 4,4'-dimethoxy-4''-boronic acid triphenylamine, Pd[P(C6H5)3]4 and K2CO3 is 1:1.2 - 3:0.05 - 0.3:3 - 5.
[0043] S3. Dissolve the dried compound 3 in tetrahydrofuran solvent, add n-butyllithium at -78 °C under a nitrogen atmosphere. Stir at -78 °C for 1 h, then add trimethyltin chloride at -78 °C, transfer to room temperature and stir for 8 - 12 h, and quench the reaction with water. Extract the organic components with petroleum ether, wash with water, and dry the organic layer over Na2SO4, then concentrate under reduced pressure to obtain the crude compound 4. Without further purification, the product is used in the following reaction.
[0044]
[0045] In the present invention, the molar ratio of compound 3, n-butyllithium, and trimethyltin chloride is 1:1 - 3:1 - 2.
[0046] S4. Dissolve the above-mentioned compound 4, 4,7-dibromo-2,1,3-benzothiadiazole in toluene. After degassing the mixture with nitrogen for 15 min, add (PPh3)2PdCl2, and reflux the reaction for 6 - 24 h. After cooling to room temperature, extract the reaction mixture with dichloromethane, wash it with saturated brine, and dry the organic phase with anhydrous MgSO4. After removing the solvent under reduced pressure, purify the product by silica gel column chromatography using a solvent mixture of dichloromethane / petroleum ether (2 / 1, v / v) as the eluent to obtain a black solid TM-1.
[0047]
[0048] In the present invention, the molar ratio of compound 4, 4,7-dibromo-2,1,3-benzothiadiazole,
[0049] (PPh3)2PdCl2 is 2 - 4:1:0.05 - 0.3.
[0050] (2) When using a benzothiadiazole derivative as the electron acceptor, the following steps are included:
[0051] Scheme A
[0052] Steps S1 - S3 are the same as those when using benzothiadiazole as the electron acceptor.
[0053] S4. Take compound 5 and iron powder in a reaction flask, introduce nitrogen into the reaction solution to remove the oxygen in the system for 15 min, then add 80 mL of acetic acid solvent, and reflux the reaction for 2 - 3 h until the mixture turns yellow. After cooling to room temperature, pour the mixture into 100 mL of ice water, filter to collect the precipitate, and wash the filter cake with n-hexane and ethanol to obtain a yellow solid compound 6.
[0054]
[0055] In the present invention, the molar ratio of compound 5 to iron powder is 1:5 - 20.
[0056] S5. Take compound 6 and thiophene glyoxal in acetic acid solvent, stir and reflux in a nitrogen atmosphere for 6 - 8 h until the reaction system turns red. After cooling to room temperature, pour the mixture into ice water, filter to collect the precipitate, and recrystallize it with methanol to obtain a red solid compound 7.
[0057]
[0058] In the present invention, the molar ratio of compound 6 to thiophene glyoxal is 1:1 - 2.
[0059] S6. Dissolve Compound 4 and Compound 7 in toluene. After degassing the mixture with nitrogen for 15 min, add (PPh3)2PdCl2 and reflux the reaction for 12 - 48 h. After cooling to room temperature, extract the reaction mixture with dichloromethane, wash it with saturated brine, and dry the organic phase with MgSO4. After removing the solvent under reduced pressure, purify the product by silica gel column chromatography using a solvent mixture of dichloromethane / petroleum ether (1 / 1, v / v) as the eluent to obtain the black solid TM-2.
[0060]
[0061] In the present invention, the molar ratio of Compound 4, Compound 7, and (PPh3)2PdCl2 is 2 - 4:1:0.05 - 0.3.
[0062] Scheme B
[0063] Steps S1 - S4 are the same as those in Scheme A when using a benzothiadiazole derivative as the electron acceptor.
[0064] S5. Take Compound 6 and phenanthraquinone in an acetic acid solvent, stir and reflux under a nitrogen atmosphere for 6 - 8 h until the reaction system turns red. After cooling to room temperature, pour the mixture into ice water, filter to collect the precipitate, and recrystallize it with methanol to obtain the red solid Compound 8.
[0065]
[0066] In the present invention, the molar ratio of Compound 6 and phenanthraquinone is 1:1 - 2.
[0067] S6. Dissolve Compound 4 and Compound 8 in toluene. After degassing the mixture with nitrogen for 15 min, add (PPh3)2PdCl2 and reflux the reaction for 12 - 48 h. After cooling to room temperature, extract the reaction mixture with dichloromethane, wash it with saturated brine, and dry the organic phase with MgSO4. After removing the solvent under reduced pressure, purify the product by silica gel column chromatography using a solvent mixture of dichloromethane / petroleum ether as the eluent to obtain the black solid TM-3.
[0068]
[0069] In the present invention, the molar ratio of Compound 4, Compound 8, and (PPh3)2PdCl2 is 2 - 4:1:0.05 - 0.3.
[0070] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and shall be included in the protection scope of the present invention. In addition, it should be understood that after reading the content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application and belong to the protection scope of the present invention.
[0071] Reference to "embodiments" herein means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The term "embodiment" appearing in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.
[0072] Unless otherwise defined, the meanings of the technical terms used herein are the same as those commonly understood by those skilled in the technical field to which this application belongs; the use of the relevant terms herein is only for describing specific embodiments and is not intended to limit this application.
[0073] Unless otherwise specified in the present invention, the reagents, instruments, equipment, etc. used are the reagents, instruments, and equipment commonly used by those skilled in the art in this field.
[0074] Example 1
[0075] This example provides a method for synthesizing a non-planar cyclic compound with intramolecular space coupling effect, which specifically includes the following steps:
[0076] S1. Under a nitrogen atmosphere, compound 1 (CPDT) and N-bromosuccinimide are dissolved in anhydrous dichloromethane at a molar ratio of 1:1 and stirred at room temperature for 8 h. The organic matter is extracted with water, washed with saturated brine, and dried with anhydrous sodium sulfate (Na2SO4), and the crude product of compound 2 is obtained by concentration and directly used in the next step without further purification.
[0077]
[0078] S2. Dissolve compound 2, 4,4'-dimethoxy-4''-boronic acid triphenylamine, Pd[P(C6H5)3]4 and K2CO3 in dioxane solution in a molar ratio of 1:1.2:0.05:3. After degassing the mixture with nitrogen for 15 min, reflux and stir for 12 h. After cooling to room temperature, the mixture is extracted with petroleum ether, and the organic layer is dried over Na2SO4. Using a mixed solvent of dichloromethane / petroleum ether with a volume ratio of 2:1 as the eluent, column chromatography purification is carried out on silica gel to obtain the brown solid compound 3.
[0079]
[0080] S3. Dissolve the dried compound 3 in tetrahydrofuran solvent, add n-butyllithium at -78 °C under a nitrogen atmosphere, where the molar ratio of compound 3, n-butyllithium, and trimethyltin chloride is 1:1:1. After stirring at -78 °C for 1 h, add trimethyltin chloride at -78 °C, then move to room temperature and stir for 8 - 12 h, and quench the reaction with water. Extract the organic components with petroleum ether, wash with water, and dry the organic layer over Na2SO4, and concentrate under reduced pressure to obtain the crude compound 4. Without further purification, the product is used in the following reaction.
[0081]
[0082] S4. Dissolve compound 4 and 4,7-dibromo-2,1,3-benzothiadiazole in toluene. After degassing the mixture with nitrogen for 15 min, add (PPh3)2PdCl2, and reflux for 6 - 24 h, where the molar ratio of compound 4, 4,7-dibromo-2,1,3-benzothiadiazole, and (PPh3)2PdCl2 is 2:1:0.05. After cooling to room temperature, extract the reaction mixture with dichloromethane, wash with saturated brine, and dry the organic phase with anhydrous MgSO4. After removing the solvent under reduced pressure, using a solvent mixture of dichloromethane / petroleum ether (2 / 1, v / v) as the eluent, purify the product by silica gel column chromatography to obtain the black solid TM-1.
[0083]
[0084] Example 2
[0085] This example provides a synthesis method of a non-planar cyclic compound with intramolecular space coupling effect, specifically including the following steps:
[0086] Steps S1 - S3 of this example are the same as steps S1 - S3 of Example 1 and will not be repeated here.
[0087] S4. Take Compound 5 and Fe powder in a reaction flask in a molar ratio of 1:5. Introduce nitrogen into the reaction solution to remove oxygen in the system for 15 min, then add 80 mL of acetic acid solvent, and reflux for 2 - 3 h until the mixture turns yellow. After cooling to room temperature, pour the mixture into 100 mL of ice water, filter to collect the precipitate, and wash the filter cake with n - hexane and ethanol to obtain the yellow solid Compound 6.
[0088]
[0089] S5. Take Compound 6 and thiophene acyloin in acetic acid solvent in a molar ratio of 1:1, stir and reflux for 6 - 8 h under a nitrogen atmosphere until the reaction system turns red. After cooling to room temperature, pour the mixture into ice water, filter to collect the precipitate, and recrystallize with methanol to obtain the red solid Compound 7.
[0090]
[0091] S6. Take Compound 4 and Compound 7 and dissolve them in toluene. After degassing the mixture with nitrogen for 15 min, add (PPh3)2PdCl2, and reflux for 12 - 48 h. Among them, the molar ratio of Compound 4, Compound 7, and (PPh3)2PdCl2 is 2:1:0.05. After cooling to room temperature, extract the reaction mixture with dichloromethane, wash with saturated brine, and dry the organic phase with MgSO4. After removing the solvent under reduced pressure, use a solvent mixture of dichloromethane / petroleum ether (1 / 1, v / v) as the eluent, and purify the product by silica gel column chromatography to obtain the black solid TM - 2.
[0092]
[0093] Example 3
[0094] This example provides a synthesis method of a non - planar cyclic compound with intramolecular space coupling effect, which specifically includes the following steps:
[0095] Steps S1 - S4 of this example are the same as steps S1 - S4 of Example 2, and will not be repeated here.
[0096] S5. Take Compound 6 and phenanthraquinone in acetic acid solvent in a molar ratio of 1:1, stir and reflux for 6 - 8 h under a nitrogen atmosphere until the reaction system turns red. After cooling to room temperature, pour the mixture into ice water, filter to collect the precipitate, and recrystallize with methanol to obtain the red solid Compound 8.
[0097]
[0098] S6. Dissolve Compound 4 and Compound 8 in toluene. After degassing the mixture with nitrogen for 15 min, add (PPh3)2PdCl2 and reflux for 12 - 48 h. Among them, the molar ratio of Compound 4, Compound 8, and (PPh3)2PdCl2 is 2:1:0.05. After cooling to room temperature, extract the reaction mixture with dichloromethane, wash with saturated brine, and dry the organic phase with MgSO4. After removing the solvent under reduced pressure, use a silica gel column chromatography with a solvent mixture of dichloromethane / petroleum ether as the eluent to purify the product, and obtain a black solid TM - 3.
[0099]
[0100] Perform performance analysis on the final products prepared in Examples 1 - 3.
[0101] Figure 1 It is a schematic diagram of the π - A - π skeleton of the TM - 1, TM - 2, and TM - 3 molecules prepared in Examples 1 - 3. From Figure 1 It can be seen that the distances between the N, H; S, H; N, S atoms of adjacent units of the molecule are less than the sum of their van der Waals radii, indicating the existence of non - covalent interactions between atoms. Under the action of the steric hindrance between the alkyl chain and the central parent nucleus, the three molecules respectively exhibit the optimal cis, trans, and cis conformations, and the dihedral angle between units is limited within 21°, preventing the molecular skeleton distortion caused by the single - bond torsion, which is beneficial to maintaining the light absorption ability and carrier transport ability of the molecule. We call this effect "intramolecular space coupling effect". The introduction of the intramolecular space coupling effect greatly reduces the synthesis and modification difficulty of planar - like molecules, making it easy to synthesize near - infrared absorption materials with extremely low bandgaps, and the molecules are finally obtained in a relatively high yield.
[0102] Figure 2 It is the light absorption spectrum of the TM - 2 molecule prepared in Example 2. From Figure 2 It can be seen that the absorption spectral band edges of the TM - 2 molecule in the dichloromethane solution and the film prepared from the chlorobenzene spin - coating solution are located at 1161 nm and 1263 nm, and the bandgap is 1.02 eV. Therefore, the non - planar cyclic compound containing intramolecular space coupling effect prepared in the present invention can be used as a near - infrared light - absorbing or emitting material for the development of optoelectronic materials.
[0103] Figure 3 It is a statistical chart of the average hole mobility of the TM - 1, TM - 2, and TM - 3 molecules prepared in Examples 1 - 3. From Figure 3 It can be seen that the maintenance of the molecular planarity of the three molecules ensures good intermolecular π - π stacking, making the hole mobilities of the three compounds all higher than 10 -4 cm 2 V -1 s -1, has the potential for hole transport materials.
[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A non-planar cyclic compound with intramolecular space coupling effect, characterized in that: The non-planar cyclic compound is a non-planar cyclic conjugated structure with a D-π-A-π-D push-pull electron structure, where a triphenylamine unit is used as an electron donor, 4,4-bis(2-ethylhexyl)-dithienocyclopentadiene is used as a π-bridge, and benzothiadiazole or its derivative is used as an electron acceptor.
2. The synthesis method of a non-planar cyclic compound with intramolecular space coupling effect according to claim 1, characterized in that, Specifically, it includes the following steps: S1. Under a nitrogen atmosphere, compound 1 and N-bromosuccinimide are dissolved in anhydrous dichloromethane and stirred at room temperature for 8 h. After extracting the organic matter, it is washed and dried, and concentrated to obtain the crude product compound 2. The structural formulas of compound 1 and compound 2 are as follows: S2. Compound 2, 4,4'-dimethoxy-4''-boronic acid triphenylamine, Pd[P(C6H5)3]4 and K2CO3 are dissolved in a dioxane solution and mixed. The mixture is degassed with nitrogen for 15 min and then refluxed and stirred for 12 h. After cooling to room temperature, the organic matter is extracted and dried. Using a mixed solvent of dichloromethane / petroleum ether as the eluent, column chromatography purification is carried out on silica gel to obtain the brown solid compound 3. The structural formula of compound 3 is as follows: S3. Compound 3 is dissolved in tetrahydrofuran. Under a nitrogen atmosphere at -78 °C, n-butyllithium is added and stirred for 1 h, then trimethyltin chloride is added, and it is stirred at room temperature for 8 - 12 h. The reaction is quenched by adding water. After extracting the organic matter, it is washed and dried, and concentrated under reduced pressure to obtain the crude product compound 4. The structural formula of compound 4 is as follows: S4. Compound 4 and benzothiadiazole or a benzothiadiazole derivative are dissolved in toluene. The mixture is degassed with nitrogen for 15 min, then (PPh3)2PdCl2 is added and refluxed for 6 - 24 h. After cooling to room temperature, the organic matter is extracted and dried. After removing the solvent under reduced pressure, using a mixed solvent of dichloromethane / petroleum ether as the eluent, the product is purified by silica gel column chromatography to obtain the black solid as the final product.
3. The synthesis method of a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, wherein: In step S1, the molar ratio of compound 1 to N-bromosuccinimide is 1 - 1.4:
1.
4. A method for synthesizing a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S1, it is extracted with deionized water, washed with saturated brine, and dried with anhydrous sodium sulfate.
5. The synthesis method of a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S2, the molar ratio of compound 2, 4,4'-dimethoxy-4''-boronic acid triphenylamine, Pd[P(C6H5)3]4, and K2CO3 is 1:1.2 - 3:0.05 - 0.3:3 - 5. The volume ratio of dichloromethane to petroleum ether in the mixed solvent of dichloromethane / petroleum ether is 2:
1.
6. A method for synthesizing a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S2, it is extracted with petroleum ether and dried with anhydrous sodium sulfate.
7. A method for synthesizing a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S3, the molar ratio of compound 3, n-butyllithium, and trimethyltin chloride is 1:1 - 3:1 - 2.
8. The synthesis method of a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S3, it is extracted with petroleum ether, washed with deionized water, and dried with anhydrous sodium sulfate.
9. The synthesis method of a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S4, the molar ratio of compound 4, benzothiadiazole or a benzothiadiazole derivative, and (PPh3)2PdCl2 is 2 - 4:1:0.05 - 0.
3. The volume ratio of dichloromethane to petroleum ether in the mixed solvent of dichloromethane / petroleum ether is 2:
1.
10. A method for synthesizing a non-planar cyclic compound with intramolecular space coupling effect according to claim 2, characterized in that: In step S4, it is extracted with dichloromethane, washed with saturated brine, and dried with anhydrous MgSO4.