Synthesis and photovoltaic application of NIR-emitting perylene-monoimide dyes with large Stokes-shift

Abstract

An efficient Sonogashira coupling protocol is developed for tetra-alkynylation at the <i>bay</i> and <i>peri</i>-positions of the perylene-monoimide (PMI) dye in its PMI(Br)₄ form. The absorption band for these PMI dyes covered from the visible to Near-infrared (NIR) region and PMI(NMe₂)₄ is found to exhibit a record-breaking Stokes-shifted NIR emission with good photovoltaic properties.