Star-shaped triarylamines – One-step metal-free synthesis and optoelectronic properties

Abstract

Triarylamine derivatives are often implemented in organic optoelectronic devices due to their excellent hole-transport properties and their versatile structural tuneability. Common synthetic routes to obtain functionalized triarylamines follow multi-step procedures utilizing transition metal catalysts. Here, we investigate the synthesis of a series of star-shaped tris(biphenylamines) by a one-step base-promoted homolytic aromatic substitution (BHAS), simultaneously attaching three peripheral arenes to the triarylamine core. We demonstrate the versatility of this synthetic route by coupling four different functionalized arenes to the core and study their influence on the optoelectronic properties. BHAS as a metal-free synthetic route produces pure organic semiconductors without transition metal residues.