D-π-A Type [7]Helicene-like Imide Derivatives with Tunable Photophysical Properties and Circularly Polarized Luminescence.

Helicenes and their derivatives show great application prospects as circularly polarized luminescence (CPL) materials, but their fluorescence quantum yields (Φs) need a breakthrough urgently. Herein, we reported a series of D-π-A type helical luminescent emitters by combining the [7]helicene-like imide acceptor with five different donors. The obtained five emitters display blue-to-orange luminescence and markedly enhanced Φ.

Synthesis and Derivatization of an Isomerized Bithiophene Imide (iBTI) Acceptor with a Controllably Twisted Backbone.

A heptagonal isomerized bithiophene imide (iBTI) acceptor has been effectively synthesized on a gram scale. Its series of β-, α',β-, α,α'-, α,α',β-, and α,α',β,β'-substituted derivatives can be obtained by controlling brominated sites. Single-crystal analyses indicate that the torsion angle of the imide backbone depends on the number and rigidity of β-substituted groups.