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

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 FeCl3 and (NH4)2S2O8 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.