具有超低LUMO/HOMO能级的稠环芳烃分子★

doi:10.6023/A23040142

摘要/Abstract

低LUMO/HOMO(最低未占分子轨道/最高占据分子轨道)能级的有机小分子的种类和数量都很少, 其设计与合成具有重要的科学价值和应用价值. 传统的设计超低LUMO/HOMO能级有机小分子的策略是在分子中引入多个氰基. 本工作设计并合成了含有四个硼氮配位键和两个酰亚胺基团的稠环芳烃分子, 不含有氰基. 该分子的LUMO能级低至－4.77 eV, HOMO能级低至－6.39 eV, 是已报道的硼氮配位键稠环小分子的最低值, 和已报道的氰基类有机小分子具有可比性. 该分子呈现曲面构型, 共轭骨架呈23.6°的二面角, LUMO和HOMO都均匀地离域在线型并苯骨架上. 它在溶液态和薄膜态都展现出明显的近红外吸收, 薄膜最大吸收波长为768 nm. 该分子可以用作p-型掺杂剂, 提高p-型高分子的电导率. 本工作开拓出不采用氰基实现有机小分子超低LUMO能级的新途径.

关键词: 能级, 硼氮配位键, 酰亚胺, p-掺杂, 稠环分子

Organic small molecules of low LUMO/HOMO (lowest unoccupied molecular orbital/highest occupied molecular orbital) energy levels are in shortage in terms of both variety and quantity. Their design and synthesis have important scientific and application value. The traditional strategy for designing organic small molecules of ultra-low LUMO/HOMO energy levels is to introduce multiple cyano groups into the molecules. In this work, a polycyclic aromatic hydrocarbon molecule containing four boron and nitrogen coordination bonds and two imide groups is designed and synthesized, without involving any cyano groups. The cyclic voltammetry examination with 0.1 mol•L⁻¹ tetrabutylammonium hexafluorophosphate solution in dichloromethane as the electrolyte solution and ferrocene as the internal standard indicates that the molecule has a low LUMO and HOMO energy level of －4.77 eV and －6.39 eV, respectively. These values are the lowest for the reported fused-ring small molecules with boron and nitrogen coordination bonds and comparable to those of the reported organic small molecules with cyano groups. The density functional theory calculation results at the B3LYP/6-31G(d,p) theoretical level show that the molecule has a curved configuration and its conjugate skeleton has a dihedral angle of 23.6°. Both LUMO and HOMO are uniformly delocalized on the linear benzoid skeleton. It shows obvious near-infrared absorption in both solution and thin film state, with maximum absorption at 768 nm in film. The molecule can be used as a p-type dopant. After its blend doping, the electrical conductivity of the film of a typical p-type polymer P3HT is improved by 3 orders of magnitude. The doping behavior is also confirmed by UV-Vis absorption spectroscopy and electron paramagnetic resonance spectroscopy. This work develops a new strategy to achieve ultra-low LUMO energy level for organic small molecules without using cyano groups.

Key words: energy level, boron nitrogen coordination bond, imide, p-doping, fused-ring molecule

引用此文

刘蕊, 孟彬, 胡俊丽, 刘俊. 具有超低LUMO/HOMO能级的稠环芳烃分子^★[J]. 化学学报, 2023, 81(10): 1295-1300.

Rui Liu, Bin Meng, Junli Hu, Jun Liu. Polycyclic Aromatic Hydrocarbon Molecule with Ultra-low LUMO/HOMO Energy Levels^★[J]. Acta Chimica Sinica, 2023, 81(10): 1295-1300.

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图/表 7

图1. (a)文献报道的LUMO能级低于－4.60 eV的代表性有机小分子, 这些分子都含有多个氰基, 其LUMO能级已给出. R为烷基链. (b)本工作报道的基于硼氮配位键和酰亚胺的有机小分子, 其LUMO能级也已给出. R为异辛基

Figure 1. (a) The representative organic small molecules with LUMO energy levels lower than －4.60 eV reported in the literature. They all contain multiple cyano groups. Their LUMO levels are indicated. R is alkyl chain. (b) The organic small molecules based on boron and nitrogen coordination bonds and imide reported in this work. Its LUMO energy level is also indicated. R is isooctyl group

图2. 4BN2I的合成路线, 反应试剂和条件: (I) CuCN, CuI, N,N-二甲基甲酰胺(DMF), 160 ℃; (II) 98% H2SO4, 60 ℃; (III) 1-溴-2-乙基己烷, K2CO3, DMF, 90 ℃; (IV) Fe, 醋酸, 120 ℃; (V) 醋酸, 120 ℃; (VI) 2-乙基-1-己胺, 甲苯, 120 ℃; (VII) BF3?Et2O, Et3N, 甲苯, 120 ℃

Figure 2. Synthetic routes of 4BN2I. Reagents and conditions: (I) CuCN, CuI, dimethylformide, 160 ℃; (II) 98% H2SO4, 60 ℃; (III) 1-bromo-2-ethylhexane, K2CO3, dimethylformide, 90 ℃; (IV) Fe, acetic acid, 120 ℃; (V) acetic acid, 120 ℃; (VI) 2-ethyl-1-hexylamine, toluene, 120 ℃; (VII) BF3?Et2O, Et3N, toluene, 120 ℃

图3. 4BN2I的DFT理论计算分子构型(a, b)和LUMO/HOMO电子云分布(c, d)

Figure 3. Molecular configuration (a, b) and LUMO/HOMO electron cloud distribution (c, d) of 4BN2I calculated by DFT theory

图4. 4BN2I的溶液态循环伏安曲线

Figure 4. Cyclic voltammetry curves of 4BN2I in solution

	E_1/2^red1 ^a/V	E_pa^ox ^a/V	E_LUMO ^b/eV	E_HOMO ^b/eV	λ_abs ^c/nm	ε_max ^c/ (L•mol⁻¹•cm⁻¹)	E_g^opt ^d/eV	λ_abs ^e/nm
4BN2I	－0.03	＋1.59	－4.77	－6.39	770/705	6.74×10⁴	1.33	706/768

表1. 4BN2I分子的光电性质

Table 1. Photoelectric properties of 4BN2I

图5. 化合物7和4BN2I的溶液态紫外-可见吸收光谱(a)和薄膜态紫外-可见吸收光谱(b)

Figure 5. UV-visible absorption spectra of compound 7 and 4BN2I in solution (a) and thin film (b)

图6. 本征P3HT薄膜和4BN2I/P3HT共混薄膜的紫外-可见吸收光谱(a)和电子顺磁共振波谱(b)

Figure 6. Ultraviolet-visible absorption spectra (a) and electron paramagnetic resonance spectra (b) of pristine P3HT film and 4BN2I/P3HT blend film

参考文献 45

[1]	Wang, C. L.; Dong, H. L.; Jiang, L.; Hu, W. P. Chem. Soc. Rev. 2018, 47, 422. doi: 10.1039/C7CS00490G
[2]	Quinn, J. T. E.; Zhu, J. X.; Li, X.; Wang, J. L.; Li, Y. N. J. Mater. Chem. C 2017, 5, 8654. doi: 10.1039/C7TC01680H
[3]	Lakshminarayana, A. N.; Ong, A.; Chi, C. Y. J. Mater. Chem. C 2018, 6, 3551. doi: 10.1039/C8TC00146D
[4]	Takimiya, K.; Osaka, I.; Nakano, M. Chem. Mater. 2014, 26, 587. doi: 10.1021/cm4021063
[5]	Li, X.-J.; Li, Y.-F. Acta Polym. Sin. 2022, 53, 995 (in Chinese).
	(李骁骏, 李永舫, 高分子学报, 2022, 53, 995.)
[6]	Li, T.-F.; Zhan, X.-W. Acta Chim. Sinica 2021, 79, 257 (in Chinese). doi: 10.6023/A20110502
	(李腾飞, 占肖卫, 化学学报, 2021, 79, 257.)
[7]	Gao, X. K.; Hu, Y. B. J. Mater. Chem. C 2014, 2, 3099. doi: 10.1039/C3TC32046D
[8]	Zaumseil, L.; Sirringhaus, H. Chem. Rev. 2007, 107, 1296. doi: 10.1021/cr0501543
[9]	Zhao, Y.; Guo, Y. L.; Liu, Y. Q. Adv. Mater. 2013, 25, 5372. doi: 10.1002/adma.v25.38
[10]	Bruder, I.; Watanabe, S.; Qu, J. Q.; Müller, I. B.; Kopecek, R.; Hwang, J.; Weis, J.; Langer, N. Org. Electron. 2010, 11, 589. doi: 10.1016/j.orgel.2009.12.019
[11]	Wang, J.; Wang, Y. Z.; Li, K. C.; Dai, X.; Zhang, L. Y.; Wang, H. Adv. Mater. 2022, 34, 2106624. doi: 10.1002/adma.v34.5
[12]	Bunz, U. H. F.; Engelhart, J. U.; Lindner, B. D.; Schaffroth, M. Angew. Chem. Int. Ed. 2013, 52, 2.
[13]	Lin, G.-B.; Luo, T.; Yuan, L.-B.; Liang, W.-J.; Xu, H. Prog. Chem. 2017, 29, 1316 (in Chinese).
	(林高波, 罗婷, 袁铝兵, 梁文杰, 徐海, 化学进展, 2017, 29, 1316.)
[14]	Lee, M. H. Adv. Electron. Mater. 2019, 5, 1900573. doi: 10.1002/aelm.v5.12
[15]	Li, S.-Y.; Zhu, C.-Y.-J.; Luo, Y.-H.; Zhang, Y.-R.; Teng, H.-M.; Wang, Z.-R.; Zhen, Y.-G. Acta Chim. Sinica 2022, 80, 1600 (in Chinese). doi: 10.6023/A22080380
	(李善武, 朱陈宇杰, 罗尹豪, 张亚茹, 滕汉明, 王宗瑞, 甄永刚, 化学学报, 2022, 80, 1600.)
[16]	Chen, H.; Moser, M.; Wang, S. H.; Jellett, C.; Thorley, K.; Harrison, G. T.; Jiao, X. C.; Xiao, M. F.; Purushothaman, B.; Alsufyani, M.; Bristow, H.; Wolf, S. D.; Gasparini, N.; Wadsworth, A.; McNeill, C. R.; Sirringhaus, H.; Fabiano, S.; McCulloch, I. J. Am. Chem. Soc. 2021, 143, 260. doi: 10.1021/jacs.0c10365
[17]	Yassar, A.; Demanze, F.; Jaafari, A.; Idrissi, M. E.; Coupry, C. Adv. Funct. Mater. 2002, 12, 699. doi: 10.1002/1616-3028(20021016)12:10【-逻辑与-】amp;lt;699::AID-ADFM699【-逻辑与-】amp;gt;3.0.CO;2-S
[18]	Liu, Z. T.; Zhang, G. X.; Cai, Z. X.; Chen, X.; Luo, H. W.; Li, Y. H.; Wang, J. G.; Zhang, D. Q. Adv. Mater. 2014, 26, 6965. doi: 10.1002/adma.v26.40
[19]	Bao, Z. N.; Lovinger, A. J.; Brown, J. J. Am. Chem. Soc. 1998, 120, 207. doi: 10.1021/ja9727629
[20]	Peltier, J. D.; Heinrich, B.; Donnio, B.; Jeannin, O.; Rault-Berthelot, J.; Jacques, E.; Poriel, C. J. Mater. Chem. C 2018, 6, 13197. doi: 10.1039/C8TC04313B
[21]	Liang, N. N.; Meng, D.; Wang, Z. H. Acc. Chem. Res. 2021, 54, 961. doi: 10.1021/acs.accounts.0c00677
[22]	Li, C.; Lin, Z.; Li, Y.; Wang, Z. H. Chem. Rec. 2016, 16, 873. doi: 10.1002/tcr.v16.2
[23]	Tu, K-H.; Wang, Y.; Kiyota, Y.; Iwahashi, T.; Ouchi, Y.; Mori, T.; Michinobu, T. Org. Electron. 2020, 87, 105978. doi: 10.1016/j.orgel.2020.105978
[24]	Maitrot, M.; Guilfaud, G.; Boudjema, B.; André, J. J.; Simon, J. J. Appl. Phys. 1986, 60, 2396. doi: 10.1063/1.337151
[25]	Aragay, G.; Frontera, A.; Lloveras, V.; Vidal-Gancedo, J.; Ballester, P. J. Am. Chem. Soc. 2013, 135, 2620. doi: 10.1021/ja309960m
[26]	Gao, Z. Q.; Mi, B. X.; Xu, G. Z.; Wan, Y. Q.; Gong, M. L.; Cheahab, K. W.; Chen, C. H. Chem. Commun. 2008, 117.
[27]	Kivala, M.; Boudon, C.; Gisselbrecht, J.-P.; Enko, B.; Seiler, P.; Müller, I. B.; Langer, N.; Jarowski, P. D.; Gescheidt, G.; Diederich, F. Chem. Eur. J. 2009, 15, 4111. doi: 10.1002/chem.v15:16
[28]	Koech, P. K.; Padmaperuma, A. B.; Wang, L.; Swensen, J. S.; Polikarpov, E.; Darsell, J. T.; Rainbolt, J. E.; Gaspar, D. J. Chem. Mater. 2010, 22, 3926. doi: 10.1021/cm1002737
[29]	Chang, J. J.; Ye, Q.; Huang, K.-W.; Zhang, J.; Chen, Z.-K.; Wu, J. S.; Chi, C. Y. Org. Lett. 2012, 14, 2964. doi: 10.1021/ol300914k
[30]	Gao, J.; Xiao, C. Y.; Jiang, W.; Wang, Z. H. Org. Lett. 2014, 16, 394. doi: 10.1021/ol403250r
[31]	Dou, C. D.; Long, X. J.; Ding, Z. C.; Xie, Z. Y.; Liu, J.; Wang, L. X. Angew. Chem. Int. Ed. 2016, 55, 1436. doi: 10.1002/anie.v55.4
[32]	Min, Y.; Dou, C. D.; Tian, H. K.; Geng, Y. H.; Liu, J.; Wang, L. X. Angew. Chem. Int. Ed. 2018, 57, 2000. doi: 10.1002/anie.v57.7
[33]	Liu, R.; Hu, J. L.; Min, Y.; Liu, J. Org. Chem. Front. 2023, 10, 923. doi: 10.1039/D2QO01900K
[34]	Min, Y.; Cao, X.; Tian, H. K.; Liu, J.; Wang, L. X. Chem. Eur. J. 2021, 27, 2065. doi: 10.1002/chem.v27.6
[35]	Min, Y.; Dou, C. D.; Tian, H. K.; Liu, J.; Wang, L. X. Chem. Eur. J. 2021, 27, 4364. doi: 10.1002/chem.v27.13
[36]	Min, Y.; Dou, C. D.; Liu, D.; Dong, H. L.; Liu, J. J. Am. Chem. Soc. 2019, 141, 17015. doi: 10.1021/jacs.9b09640
[37]	Min, Y.; Dong, C. S.; Tian, H. K.; Liu, J.; Wang, L. X. ACS Appl. Mater. Interfaces 2021, 13, 33321. doi: 10.1021/acsami.1c08514
[38]	Wu, Z. H.; Huang, Z. T.; Guo, R. X.; Sun, C. L.; Chen, L. C.; Sun, B.; Shi, Z. F.; Shao, X. F.; Li, H. Y.; Zhang, H. L. Angew. Chem. Int. Ed. 2017, 56, 13031. doi: 10.1002/anie.v56.42
[39]	Sun, Y. M.; Di, C. A.; Xu, W.; Zhu, D. B. Adv. Electron. Mater. 2019, 5, 1800825. doi: 10.1002/aelm.v5.11
[40]	Lee, S.; Kim, S.; Pathak, A.; Tripathi, A.; Qiao, T.; Lee, Y.; Lee, H.; Woo, H. Y. Macromol. Res. 2020, 28, 531. doi: 10.1007/s13233-020-8116-y
[41]	Liu, J.; Ye, G.; Zee, B. V. D.; Dong, J. J.; Qiu, X. K.; Liu, Y. R.; Portale, G.; Chiechi, R. C.; Koster, L. J. A. Adv. Mater. 2018, 30, 1804290. doi: 10.1002/adma.v30.44
[42]	Bredas, J. L.; Street, G. B. Acc. Chem. Res. 1985, 18, 309. doi: 10.1021/ar00118a005
[43]	Xuan, Y.; Liu, X.; Desbief, S.; Leclère, P.; Fahlman, M.; Lazzaroni, R.; Berggren, M.; Cornil, J.; Emin, D.; Crispin, X. Phys. Rev. B 2010, 83, 115454. doi: 10.1103/PhysRevB.83.115454
[44]	Shin, Y.; Massetti, M.; Komber, H.; Biskup, T.; Nava, D.; Lanzani, G.; Caironi, M.; Sommer, M. Adv. Electron. Mater. 2018, 4, 1700581. doi: 10.1002/aelm.v4.10
[45]	Kiefer, D.; Giovannitti, A.; Sun, H.; Biskup, T.; Hofmann, A.; Koopmans, M.; Cendra, C.; Weber, S.; Koster, L. J. A.; Olsson, E.; Rivnay, J.; Fabiano, S.; McCulloch, I.; Müller, C. ACS Energy Lett. 2018, 3, 278. doi: 10.1021/acsenergylett.7b01146