Preparation of Polyaminopyridines Using a CuI/l-Proline-Catalyzed C-N Polycoupling Reaction

Abstract

Polyaminopyridines (PAPy) were chemically prepared from amino-bromopyridines by a CuI/l-proline-catalyzed C-N polycondensation reaction. The formation of the polymer was confirmed by GPC, XRD, XRF, FTIR, UV-vis (λmax = 400 nm), 1H and 13C NMR. The number-average molecular weights (Mn) were estimated by end-group analysis using X-ray fluorescence (up to 6000 Da). TGA analysis of PAPy with higher Mn showed greater thermal stability up to 170 oC. Viscosity measurements of polymer in formic acid at 30 oC indicated a polyelectrolyte nature of PAPy solutions. Furthermore, the amorphicity of the material was observed by X-ray diffraction analysis.