Linkage effects of linear D–π–A–π–D type diketopyrrolopyrrole-triphenylamine based solution-processable organic small molecule photovoltaic materials
作者:Changyan Ji、Lunxiang Yin、Lihui Wang、Tao Jia、Shixiang Meng、Yingji Sun、Yanqin Li
DOI:10.1039/c3tc32214a
日期:——
Four novel DâÏâAâÏâD-type small molecules (SMs) were synthesized and their Ï-linkage effects were investigated. Among them, SM2 with vinylene as the Ï-linkage exhibited better molecular coplanarity, reaching a relatively higher power conversion efficiency (PCE) of 3.76%. SM3 and SM4 with acetylene and acrylonitrile as Ï-linkages exhibited relatively higher open-circuit voltages (VOC) of 0.93 V and 0.90 V, respectively, owing to their deep-lying HOMO levels. These results gave an important guide for developing new materials in solution-processed small molecule solar cells.
研究人员合成了四种新型 DâÏâAâÏâD 型小分子(SMs),并研究了它们的Ï-连接效应。其中,以乙烯为Ï-连接键的 SM2 表现出更好的分子共面性,功率转换效率(PCE)相对较高,达到 3.76%。以乙炔和丙烯腈为Ï-连接的 SM3 和 SM4 由于具有深层 HOMO 水平,开路电压(VOC)相对较高,分别为 0.93 V 和 0.90 V。这些结果为开发溶液法小分子太阳能电池新材料提供了重要指导。
Double-coupling of dibromo arenes with aryltriolborates for synthesis of diaryl-substituted planar frameworks
作者:Gao-Qiang Li、Yasunori Yamamoto、Norio Miyaura
DOI:10.1016/j.tet.2011.06.083
日期:2011.9
A new method for simple and practical synthesis of diaryl-substituted arenes using potassium aryltriolborates was developed. Double-cross-coupling of dibromo arenes with aryltriolborates was carried out in the presence of a palladium catalyst, such as Pd(OAc)(2), Pd(PPh3)(4) or Pd(OAc)(2)/BIPHEP. The use of CuCl (40 mol %) with a palladium catalyst was found to be highly effective to give diaryl-substituted aromatic compounds in good yields. (C) 2011 Elsevier Ltd. All rights reserved.
Synthesis and spectroscopic study of phenylene–(poly)ethynylenes substituted by amino or amino/cyano groups at terminal(s): electronic effect of cyano group on charge-transfer excitation of acetylenic π-systems
To gain insight into substituent electronic effect on charge-transfer excitation of acetylenic pi-systems, phenylene-(poly)ethynylenes substituted by Ph2N or Ph2N/cyano groups were synthesized by combination of Sonogashira coupling and double elimination protocol of beta-substituted sulfones. These substituted phenyleneethynylenes showed large molar absorption coefficients epsilon, and emitted strong fluorescence upon UV light irradiation. Phenylene (poly)ethynylenes, which involve butadiyne or hexatriyne motifs, emitted fluorescence in remarkably lower fluorescence quantum yields Phi(F) as their polyethynylene motifs -(C C)(n)- expanded. The drastic decrease of fluorescence quantum yields Phi(F) were explained in terms of increasing nonradiative reaction rate constants k(nr), which had been determined by the corresponding fluorescence quantum yields Phi(F) and lifetime values tau. The emission underwent a large bathochromic shift in polar solvents because the charge-separated excited state is more stabilized than the ground state. Comparison of slope values rho in Lippert/Mataga plot for the Ph2N and Ph2N/cyano-substituted phenylene (poly)ethynylenes revealed that the latter underwent large change of dipole moments upon photo-excitation although highly expanded acetylenic pi-systems with cyano group did little. (C) 2010 Elsevier Ltd. All rights reserved.
Synthesis and spectroscopic study of diphenylamino-substituted phenylene-(poly)ethynylenes: remarkable effect of acetylenic conjugation modes
A series of diphenylamino-substituted phenylene-(poly)ethynylenes were successfully synthesized by a combination of Sonogashira coupling and double elimination protocol of p-substituted sulfones. When UV-light was irradiated, the amino-substituted phenylene-(poly)ethynylene emitted strong luminescence. The emission underwent a large bathochromic shift in polar solvent because of stabilization of their charge-separated excited states. Analyses of fluorescence life times of aminoacetylenes revealed that radiationless process was suppressed in the polar solvent CH2Cl2, resulting in high quantum yields. (C) 2009 Elsevier Ltd. All rights reserved.
High performance asymmetrical push–pull small molecules end-capped with cyanophenyl for solution-processed solar cells