85664-13-7Relevant academic research and scientific papers
Electron-transfer reactivity in some simple cobalt(III)-cobalt(II) couples. Franck-Condon vs. electronic contributions
Endicott, John F.,Brubaker, George R.,Ramasami,Kumar, Krishan,Dwarakanath, Kaddi,Cassel, Jonathan,Johnson, David
, p. 3754 - 3762 (2008/10/08)
Electron-transfer rates involving the Co(sep)3+,2+ (sep = 1,3,6,8,10,13,16,19-octaazabicyclo[6.6.6]eicosane) and Co(en)33+,2+ couples have been examined for any differences in contributions of Franck-Condon and electronic terms to the rate constants. Rate constants for cross-reaction oxidations of Co(sep)2+ follow the classically predicted dependence of the Franck-Condon factor on ΔGab°. Far-infrared and Raman vibrational spectra of M(sep)3+/M(en)33+ (M = Co, Rh) are in very close correspondence. As a consequence, the force constants of the M-N stretching modes must also be comparable (differing by less than 10%) in the Co(sep)3+ and Co(en)33+ complexes. Strain energy calculations based on these and other published force constants are consistent with the differences in self-exchange rates and indicate upper limits on the Franck-Condon term in the rate constants consistent with significant contributions from electronic factors in both exchange reactions.
