Interaction of nitric oxide with cobalt(II) phthalocyanine: kinetics, equilibria and electrocatalytic studies

The coordination of nitric oxide (NO) to cobalt(II) phthalocyanine (CoPc) i n dimethyl sulphoxide (DMSO has been studied. CoPc coordinates with NO in a 1:1 ratio, forming a CoPc(NO) species. The IR band observed nt 1680 cm(-1) is assigned to the coordinated NO. In the presence of, excess NO, pseudo f irst order kinetics were followed. The observed rate constant, k(f), was de termined to be 15.0 +/-0.3 dm(-3) mol(-1) s(-1) and the equilibrium constan t was K = 5.4 +/- 0.4 x 10(4)dm(3)mol(-1). Solution or adsorbed CoPc cataly ses the reduction of NO. The products of reduction include NH3 and NH2OH. ( C) 1998 Elsevier Science Ltd. All rights reserved.