Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies
One electron oxidation of cobalt(II) can occur from either the cobalt d or porphyrin {pi} orbitals depending on the choice of porphyrin and reaction media. Oxidation of (octaethylporphyrinato)cobalt(II), (OEP)Co{sup II} (1), in the presence of ligands such as H{sub 2}O and CO produces diamagnetic five and six coordinate complexes of cobalt(III). In the absence of additional ligands to coordinate with Co(III) the first oxidation of [(OEP)Co{sup II}]{sup +} (2). Metalloporphyrin {pi} cation radical complexes and dimers of the OEP derivatives have been extensively investigated. This article reports on the interconversion of the paramagnetic (S = 1) monomer, [(OEP)Co{sup II}]{sup +} (2), with a diamagnetic dimer, [(OEP)-Co{sup II}]{sub 2}{sup 2+} (3), in dichloromethane solvant. {sup 1}H NMR shift and line width studies in CD{sub 2}Cl{sub 2} are applied in evaluating the thermodynamic and activation parameters for homolytic dissociation of the diamagnetic dimer (3).
- Research Organization:
- Univ. of Pennsylvania, Philadelphia, PA (US)
- Sponsoring Organization:
- National Science Foundation; US Department of Energy
- DOE Contract Number:
- FG02-86ER13615
- OSTI ID:
- 20003193
- Journal Information:
- Inorganic Chemistry, Journal Name: Inorganic Chemistry Journal Issue: 17 Vol. 38; ISSN INOCAJ
- Country of Publication:
- United States
- Language:
- English
Similar Records
Reactions of isocyanides with rhodium porphyrins. Formation of formimidoyl and carbamoyl complexes and CN-R bond cleavage
Resonance Raman, X-ray crystallographic, and magnetic susceptibility studies of metal-metal-bonded MoRu and WOs porphyrin dimers. 1: Evidence for an unusual MO diagram