N-Functionalized Poly(dithieno[3,2-<i>b</i>:2‘,3‘-<i>d</i>]pyrrole)s:  Highly Fluorescent Materials with Reduced Band Gaps

Abstract

Oxidative polymerization studies of N-functionalized dithieno[3,2- b:2‘,3‘- d ]pyrroles (where substituent = hexyl, octyl, decyl, octadecyl, tert -butyl, 2-ethylhexyl, or p -hexylphenyl) via both chemical oxidation and electropolymerization are presented. While electropolymerized samples are insoluble, it is possible to isolate soluble materials via chemical oxidation methods. Solution and solid-state characterization of the resulting polymeric materials is described, including photophysical and electrochemical studies, and these properties are compared to related polythiophene materials. In addition to reduced band gaps (∼1.7 eV), these materials exhibit good red emission with solution quantum efficiencies up to 34%.