Oxalato complexes of Co(II) and Co(III)

Electron transfer reaction between cytochrome c and trisoxalatocobalt(III)†

“…Characteristic bands: for cyt c II at 550 nm (ε = 27600 dm 3 mol Ϫ1 cm Ϫ1 ) and 420 nm (ε = 129000 dm 3 mol Ϫ1 cm Ϫ1 ); for cyt c III at 521 nm (ε = 9100 dm 3 mol Ϫ1 cm Ϫ1 ) and 416 nm (ε = 89000 dm 3 mol Ϫ1 cm Ϫ1 ). 26, 27 The absorption spectrum of the trisoxalatocobalt() complex shows two bands at 605 nm (ε = 175 dm 3 mol Ϫ1 cm Ϫ1 ) and 425 nm (ε = 230 dm 3 mol Ϫ1 cm Ϫ1 ), whereas the trisoxalatocobalt() complex [Co(ox) 3 ] 4Ϫ is characterized by a single maximum at 534 nm. The comparison of absorbance data with literature values was used to determine the concentrations of the species [Co(ox) 3 ] 3Ϫ and cytochrome c in solution.…”

Photochemistry of transition-metal coordination compounds

“…One of the first detailed mechanisms for Co (III) photolyses recognized this problem.44•267 The primary act was considered to be a homolytic bond fission, and in terms of an acidopentaammine, the process was hv Co(NH3)5X2+->-[Co(NH3)s2+X] + (67) where represents excess energy, which is supposed to be dissipated rapidly into the medium. Cage reactions then followed, in which X could be recoordinated, with further release of energy, or could begin to diffuse away.…”

Kinetic studies on the oxidation of hexa-aquamolybdenum(III) with [IrCl6]2–, [Co(C2O4)3]3–, and aquavanadium(IV)

“…Peak positions h/nm (E/M-' cm-') at 420(215) and 603(165) were in good agreement with literature values, 420(220) and 605(170). 19 The solid (and solutions) are photosensitive, and containing vessels were therefore covered with aluminium foil. first-order plots of absorbance change at 420 nm were linear for 2.5 h (about one half-life) and gave a rate constant of 7.7 x s-' as compared to a value 12.6 x s-' in 2.0 M HCIO,.…”