Thionation-enhanced through-space electronic coupling and excited-state dynamics in helicene diimides

Abstract

Thionation provides a simple heteroatom substitution strategy to enhance through-space electronic coupling in helically constrained π-systems. A thionated [8]helicene diimide shows pronounced LUMO stabilization and nearly doubled electronic coupling between the spatially aligned imide units. Spectroscopic and computational studies reveal enhanced charge delocalization and altered excited-state dynamics.