Department of Chemical Sciences, Indian Institute of Science Education and Research, Kolkata, PO: BCKV campus main office, Mohanpur, 741252, Nadia, West Bengal, India.
Org Biomol Chem. 2011 Oct 21;9(20):6963-72. doi: 10.1039/c1ob05866e. Epub 2011 Aug 30.
Selenophene and thiophene capped cyclopenta[c]selenophenes were synthesized and characterized. Crystal structure determination of some representative compounds revealed that the substitution at 3,4-position in the form of cyclopentane ring of selenophene or thiophene does not make any significant twist in the trimer backbone, making the cooligomer nearly planar. All the cooligomers were electrochemically polymerized and compared with thiophene capped cyclopenta[c]thiophene polymer. DFT calculations predict that the cyclopentane substitution on the third repeating unit (and in general) of one dimensional polymer neither disturb the planarity nor causes any significant twist on the polymeric backbone unlike the 3,4-dialkyl substitution. The electrochemically prepared selenophene based polymers showed low band gap compared to that of thiophene analogues. Cyclopentane substitution on selenophene as well as thiophene makes the resulting polymer oxidatively more stable when compared to more familiar poly-ethylenedioxythiophene (PEDOT) or poly-ethylenedioxyselenophene (PEDOS) systems. Alternate polymers of cyclopenta[c]selenophenes (CPS)/cyclopenta[c]thiophene (CPT) and thiophene/selenophene possess the energy of HOMO and LUMO significantly lower than that of homopolymers of CPS and CPT, however, possess higher band gap than PCPS.
硒吩和噻吩封端的环戊[c]硒吩被合成并进行了表征。一些代表性化合物的晶体结构测定表明，硒吩或噻吩的 3,4-位以环戊烷环的形式取代不会使三聚体主链发生任何显著扭曲，使齐聚物几乎呈平面。所有齐聚物都进行了电化学聚合，并与噻吩封端的环戊[c]噻吩聚合物进行了比较。DFT 计算预测，一维聚合物中第三个重复单元（一般情况下）上的环戊烷取代既不会破坏平面性，也不会像 3,4-二烷基取代那样对聚合物主链造成任何显著扭曲。与噻吩类似物相比，电化学制备的硒吩基聚合物的带隙较低。与更常见的聚 3,4-亚乙基二氧噻吩（PEDOT）或聚 3,4-亚乙基二氧硒吩（PEDOS）系统相比，硒吩和噻吩上的环戊烷取代使所得聚合物的氧化稳定性更高。环戊[c]硒吩（CPS）/环戊[c]噻吩（CPT）和噻吩/硒吩的交替聚合物的 HOMO 和 LUMO 能量明显低于 CPS 和 CPT 的均聚物，但比 PCPS 的带隙更高。
