Nitric Oxide Oxidation Mediated by Substituted Nickel Phthalocyanines: A Theoretical Viewpoint

• Published in: Journal of physical chemistry. C 2012-08, Vol.116 (32), p.16979-16984
• Main Authors: Cárdenas-Jirón, Gloria I, Gonzalez, Cristhy, Benavides, Julie
• Format: Article
• Language: English
• Subjects: Catalysis; Catalytic reactions; Chemistry; Exact sciences and technology; General and physical chemistry; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp3025232

The oxidation of nitric oxide (NO) mediated by substituted nickel phthalocyanines (NiPc(X) n ) has been investigated for 19 complexes at the B3LYP and M05-2X/LANL2DZ/6-31G(d) levels of theory. Unimolecular reactivity descriptors like chemical potential and electrophilicity were calculated for NiPc(X) n , giving an account of the substituent effect and indicating that electron-withdrawing groups favor the reduction of NiPc(X) n . Bimolecular reactivity descriptor as donor–acceptor hardness was used to get information about the affinity of NO by NiPc(X) n and suggests that Ni(III) has better affinity than Ni(II). A mechanism where Ni(III) catalyzes the oxidation of NO instead of Ni(II) was proposed. Optimized molecular structures calculated for the NO···NiPc(X) n adducts confirm that a larger charge transfer occurs from NO to Ni(III)Pc(X) n in comparison with Ni(II)Pc(X) n and that the reduction in the former complexes happens on the phthalocyanine ligand.