Experimental and theoretical studies of 2,5‐diphenyl‐1,4‐distyrylbenzenes with all‐cis‐ and all‐trans double bonds: chemical structure determination and optical properties
Experimental and theoretical studies of 2,5‐diphenyl‐1,4‐distyrylbenzenes with all‐cis‐ and all‐trans double bonds: chemical structure determination and optical properties
复制标题
DOI：
10.1002/poc.935
复制
发表时间：
2005-09
影响因子：
1.8
通讯作者：
Zengqi Xie;Bing Yang;Linlin Liu;Mao Li;D. Lin;Yuguang Ma;G. Cheng;Shiyong Liu
中科院分区：
文献类型：
--
作者：
Zengqi Xie;Bing Yang;Linlin Liu;Mao Li;D. Lin;Yuguang Ma;G. Cheng;Shiyong Liu
通过Wittig反应合成了具有全顺式（cis-DPDSB）和全反式（trans-DPDSB）双键的2，5-二苯基-1，4-二苯乙烯基苯（DPDSB），并详细讨论了顺式和反式异构体的结构和光学性质的差异。通过核磁共振谱、红外光谱、X射线晶体学、差示扫描量热法（DSC）和电化学方法对两种化合物进行了表征。X射线衍射分析和分子模拟结果表明，顺式DPDSB的结构沿着二苯乙烯基苯和三联苯方向均明显偏离平面性，晶体中分子间相互作用较小。的cisisisomer显示出一个大的蓝移的吸收光谱中的反式异构体相比，和循环伏安测量得到的带隙为3.16和2.97 eV的顺式和反式DPDSB，分别。这两种化合物在固态下都显示出异常强的蓝色荧光，这可能是由于两种异构体中存在的分子间相互作用较弱，这是由于取代的苯基引起的空间位阻较大。DSC实验表明，这两种异构体都具有优异的热稳定性，这表明它们可以用作活性层来制作稳定的器件。前线分子轨道和阴阳离子性质的量子化学计算表明，HOMO和LUMO完全位于二苯乙烯基苯方向，且无论是顺式还是反式DPDSB，二苯乙烯基苯段都比三联苯段具有更灵敏的电活性.
2,5-Diphenyl-l,4-distyrylbenzene (DPDSB) with all-cis (cis-DPDSB) and all-trans double bonds (trans-DPDSB) were synthesized by Wittig reaction and the differences in structural and optical properties between the cis- and trans-isomers are discussed in detail. Both compounds were fully characterized by NMR spectroscopy, FT-IR spectroscopy, x-ray crystallography, differential scanning calorimetry (DSC) and electrochemical methods. X-ray analysis and molecular simulation revealed that the structure of cis-DPDSB obviously deviates from planarity along both the distyrylbenzene and terphenyl directions, and less intermolecular interaction exists in crystal. The cisisomer shows a large blue shift in the absorption spectrum in comparison with that of the trans-isomer, and cyclic voltammetric measurements give bandgaps of 3.16 and 2.97 eV for cis- and trans-DPDSB, respectively. Both compounds show unusually strong blue fluorescence in the solid state, probably due to the weak intermolecular interaction existing in both isomers owing to the large steric hindrance induced by the substituted phenyl groups. DSC experiments determined that both isomers have excellent thermal stability, which indicates that they can be used as active layers to make stable devices. Quantum chemical calculations for the frontier molecular orbital and the cation and anion properties reveal that the HOMO and LUMO are completely localized in the distyrylbenzene direction and the distyrylbenzene segment has more sensitive electroactivity than the terphenyl segment whether it is cis- or trans-DPDSB.