Coordination and reduction of nitric oxide on a cobalt tetraphenylporphyrin imidazole complex

Article abstract of DOI:10.1021/ic00132a050

Coordination and reduction of nitric oxide on cobalt tetraphenylporphyrin anchored to imidazole on SiO₂ were studied to obtain basic information for development of a novel catalyst. The complex adsorbed nitric oxide, giving a υ_NO band around 1650 cm^-1, which is red shifted from that of gaseous nitric oxide. The shift indicates significant activation of nitric oxide promoted by the dπ orbitals of the cobalt ion, which is influenced through strong π donation from the axially coordinating imidazole ligand. The complex catalytically reduced nitric oxide with hydrogen more effectively than CoTPP on SiO₂. A reaction mechanism based on the trans effect of imidazole for the coordination and activation of nitric oxide was proposed.