Formation,characterization and catalytic activity of PD-polyheteroarylenes complexes

High molecular weight polybenzimidazoles, poly(N-phenyl)benzimidazoles], polynaphthoylenebenzimidazoles and poly(naphthoylene-s-triazoles) were obtained using well-known polycyclodehydration processes as well as new reactions for their preparation -reductive polyheterocyclization and “activated” poly-cyclocondensation. Treatment of polymers obtained with PdCl₂ led to the formation of Pd-containing polyheteroarylenes complexes. Pd^II bound to the polymers was reduced to Pd° by treatment with hydrogen or NaBH₄. Pd-polyheteroarylenes complexes obtained may be used as catalysts for the hydrogenation of alkenes and alkynes, for the selective hydrogenation of the triple bonds of unsaturated hydrocarbons in the presence of double bonds etc. Of especially great interest is the utilization of Pd-polybenzimidazole as catalyst for carbonylation of nitrobenzene and different halogen-substitited nitrobenzenes in the presence of alcohols leading to the formation of carbamates.