(<i>R</i>)-Binaphthyl derivatives as chiral dopants: substituent position controlled circularly polarized luminescence in liquid crystals

Abstract

A series of nonbridged axially chiral binaphthyl derivatives were synthesized and used as chiral dopants for chiral nematic liquid crystals (N*-LCs). It was found that binaphthyl derivatives substituted at 3,3' positions or 2,2' positions of binaphthyl rings could induce N*-LCs to show opposite circularly polarized luminescence (CPL) signals, despite having the same configuration. Additionally, a CPL switch could be constructed in these N*-LCs regulated by the applied electric field.