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Unsymmetric Dithienosilole Insertion into Helicene Enhances Circularly Polarized Luminescence
Xinyu Guo1, Wan Xu1, Jia Tang1
1Institute of Nanoscience and Engineering, Henan University, Kaifeng 475004, China.
Abstract:
Three S,Si-heterohelicenes, STB[6]H, STB[7]H, and DSTB[7]H, with unsymmetric dithienosilole (DTS) were synthesized via a three-step strategy featuring Wittig and McMurry reactions, followed by photocyclization of diarylethene precursors. Their helically molecular structures were confirmed by X-ray crystal analysis. Their fluorescence quantum yields (ΦFL) were enhanced with the increase of the benzene unit or DTS moiety in the helicene skeletons. The enantiomers of DSTB[7]H containing two DTS moieties exhibit better performance of circularly polarized luminescence (CPL) than that of STB[7]H, with both luminescence dissymmetry factors (|glum|) reaching magnitudes on the order of 10-3.
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