The solid-state reaction of a functionalised polypyrrole; analysis using high resolution X-ray photoelectron spectroscopy

A novel series of copolymer films was prepared by electrochemical oxidation of N-(2-(trimethylsilyl)-ethoxymethyl)-pyrrole, (I), and pyrrole mixtures in acetonitrile solution, and characterized by a combination of electrochemical and spectroscopic techniques. The compositions of the copolymers (and the homopolymer, poly(I)) were determined by integration of the N(1s) and Si(2p) regions of the thin film X-ray photoelectron spectra. Addition of a small amount of pyrrole to a solution of only monomer I resulted in copolymers containing a disproportionately large amount of unsubstituted pyrrole units, consistent with the radical cation of the substituted monomer being very much less reactive towards polymer formation. The reactivities of the resultant films to fluoride ion were explored, with the goal of cleaving the N-substituent from the polymer to generate cavities of controlled geometry. XPS provided quantitative information on the rate and extent of this process as a function of (co)polymer composition.