Synthesis and characterization of oxazinone and oxazoline substituted pyrroles: Towards electrically conducting bi-functional copolymers

Abstract

The synthesis of N-(3-aminopropyl)pyrrole and N-(2-carboxyethyl)pyrrole was reviewed and repeated. Both compounds were utilized as pre-cursors for the synthesis of oxazinone and oxazoline modified pyrroles by different synthetic pathways. The N-substituted pyrroles were characterized by 1H NMR, ATR-FTIR, and MALDI-TOF MS. The chemical oxidative copolymerization of pyrrole and its derivatives was carried out in various solvent systems using FeCl 3 and (NH 4) 2S 2O 8 as oxidants. Furthermore, sodium poly(styrene sulfonate) was used as dopant leading to core-shell-like structures, and, after the copolymerization of pyrrole with oxazinone or oxazoline functionalized monomers, to exceptionally increased conductivities. The produced (co-)polymers were characterized in terms of their chemical composition, morphology, and electrical conductivity. Oxazinone and oxazoline moieties in the copolymers were confirmed by ATR-FTIR. Furthermore, the retained reactivity of oxazinone and oxazoline functions after chemical oxidative copolymerization was evidenced by model reactions with 1-pyrenemethylamine and 1-pyreneacetic acid, respectively, and subsequent fluorescence microscopy and spectroscopy.