title: Variation of oxo-transfer reactivity of (nitro)cobalt picket fence porphyrin with oxygen-donating ligands.
abstract: Derivatives of (nitro)cobalt picket fence porphyrin with oxygen-donating ligands have been prepared in solution and in the solid state. Crystal structures of two of these derivatives, (H2O)CoTpivPP(NO2) and (CH3OH)CoTpivPP(NO2), have been determined. The ethanol complex (C2H5OH)Co(TPP)(NO2) has been obtained and spectrally characterized using sublimed layers methodology. The formation constant and the DeltaH degrees value of the association reaction with ethanol have been determined by FTIR measurements in CCl4 solution. Catalytic oxygen activation and oxo-transfer reactions of these derivatives have been assessed in solution. Correlations between the oxo-transfer reactivity, thermodynamics, and characteristics of the nitro ligand show that although calculated and observed ONO vibrational spectra and bond lengths suggest activation of the NO2 ligand and enhanced oxo-transfer reactions as seen in the analogous five-coordinate complexes, density functional theory calculations support that thermodynamics limits oxo-atom transfer reactions in these six-coordinate systems.
authors.affiliation: Department of Chemistry and Physics, Coastal Carolina University, P.O. Box 261954, Conway, South Carolina 29526-6054, USA. jgoodwin@coastal.edu
authors.forename: John
authors.initials: J
authors.lastname: Goodwin
authors.forename: Tigran
authors.initials: T
authors.lastname: Kurtikyan
authors.forename: Jean
authors.initials: J
authors.lastname: Standard
authors.forename: Rosa
authors.initials: R
authors.lastname: Walsh
authors.forename: Bin
authors.initials: B
authors.lastname: Zheng
authors.forename: Diedre
authors.initials: D
authors.lastname: Parmley
authors.forename: James
authors.initials: J
authors.lastname: Howard
authors.forename: Shaun
authors.initials: S
authors.lastname: Green
authors.forename: Arthur
authors.initials: A
authors.lastname: Mardyukov
authors.forename: David E
authors.initials: DE
authors.lastname: Przybyla