Polymerization of Primary Amines with Sulfur Monochloride to Yield Red Polymers with a Conjugated SN Backbone

Abstract

A series of polymers that possessed a backbone solely composed of alternating nitrogen and sulfur single bonds were synthesized for the first time. The structures of these polymers were based on polythiazyl (SN)x, which only possesses nitrogen and sulfur and is electrically conducting at room temperature in the absence of doping and superconducting at low temperatures. The polymers reported in this manuscript were synthesized using the reaction between sulfur dichloride (SCl2) and either anilines or octylamine. The isolated yields ranged from 48% to 74%, and the molecular weights were found using light scattering and refractive index detectors to be 6,200–35,000 g mol–1. The UV–vis spectra of the polymers were obtained, and the polymers possessed peak maxima around 450 nm and appeared red. The poly[(N,N-amino)sulfide] (polyNAS) synthesized from octylamine also was red, which demonstrated that the color was due to conjugation along the NS backbone. These polymers are the first polymers containing a backbone of alternating N and S, and are easily processed due to the groups attached to the nitrogens.