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Title: Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies

Abstract

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).

Authors:
; ;
Publication Date:
Research Org.:
Univ. of Pennsylvania, Philadelphia, PA (US)
Sponsoring Org.:
National Science Foundation (NSF); USDOE
OSTI Identifier:
20003193
DOE Contract Number:  
FG02-86ER13615
Resource Type:
Journal Article
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 38; Journal Issue: 17; Other Information: PBD: 23 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
40 CHEMISTRY; DIMERIZATION; PORPHYRINS; ETHYL RADICALS; CATIONS; THERMODYNAMICS; KINETICS; SPECTROSCOPY; COBALT COMPOUNDS

Citation Formats

Ni, Y., Lee, S., and Wayland, B.B. Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies. United States: N. p., 1999. Web. doi:10.1021/ic9904034.
Ni, Y., Lee, S., & Wayland, B.B. Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies. United States. doi:10.1021/ic9904034.
Ni, Y., Lee, S., and Wayland, B.B. Mon . "Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies". United States. doi:10.1021/ic9904034.
@article{osti_20003193,
title = {Dimerization of the octaethylporphyrin {pi} cation radical complex of cobalt(II): Thermodynamic, kinetic, and spectroscopic studies},
author = {Ni, Y. and Lee, S. and Wayland, B.B.},
abstractNote = {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).},
doi = {10.1021/ic9904034},
journal = {Inorganic Chemistry},
number = 17,
volume = 38,
place = {United States},
year = {1999},
month = {8}
}