Triarylborane‐Based Helical Donor–Acceptor Compounds: Synthesis, Photophysical, and Electronic Properties

The synthesis and characterization of 10‐(dimesitylboryl)‐N,N‐di‐p‐tolylbenzo[c]phenanthren‐4‐amine (3‐B(Mes)2‐[4]helix‐9‐N(p‐Tol)2 1) and 13‐(dimesitylboryl)‐N,N‐di‐p‐tolyldibenzo[c,g]phenanthren‐8‐amine (3‐B(Mes)2‐[5]helix‐12‐N(p‐Tol)2 2) are reported herein. Their electrochemical and photophysical properties have been studied experimentally and theoretically. The donor and acceptor‐substituted helicene derivatives exhibit moderate fluorescence quantum yields in THF (Φf=0.48 and 0.61 for 1 and 2, respectively), which are higher than unsubstituted ones (Φf=0.18 for [4]helicene; Φf