Modification of [5]Helicene with Dimesitylboryl: One Way To Enhance the Fluorescence Efficiency.
Zheng-Hua ZhaoMeng-Yuan ZhangDi-Hong LiuCui-Hua ZhaoPublished in: Organic letters (2018)
The efficient synthetic route was disclosed to prepare structurally asymmetric [5]helicenes, which are substituted with either BMes2 (7B-HC) or both BMes2 and NMe2 (8B5NMe2-HC, 7B5NMe2-HC). Compared with the parent [5]helicene, these compounds show greatly enhanced fluorescence. In addition, they still retain fairly strong fluorescence in the solid state. Moreover, the complexation of 8B5NMe2-HC and 7B5NMe2-HC with fluoride can induce significant blue shift in fluorescence and the formed complexes are also highly fluorescent.