Ruthenium polypyridine complexes, rate

Scott JR, Willie A, MacLean M, et al. Intramolecular electron transfer in cytochrome b5 labeled with ruthenium(II) polypyridine complexes rate measurements in the Marcus inverted region. J Am Chem Soc 1993 115 6820-4. 

Along with the distances associated with proton transfer, the distance-dependence of electron transfer on PCET reactions of phenols has also been of considerable interest. To study the effect of distance on the rates of phenol oxidation, Wenger and coworkers synthesized a series of heteroleptic ruthenium polypyridine complexes where the distance from the metal to the distal phenol was varied as a function of the... 

In related model complex studies, Isied and coworkers, have examined photo-induced (or pulse-radiolytically initiated) electron-transfer processes in which a polypyridine-ruthenium(II) complex is linked by means of a 4-carboxylato,4 -methyl,2,2 -bipyridine ligand and a polyproline chain to a [Co(NH3)5] + or [(-NH-py)Ru (NH3)5] acceptor. Chains composed of from zero to six cis-prolines have been examined. The apparent distance dependence of the electron-transfer rate constant, corrected for variations in the solvent reorganizational energy, seems to exhibit two types of distance dependence, 0.7-1A for short chains and /3 a0.3 A for long chains. A very detailed theoretical analysis of electron transfer in the complexes with four proline linkers has indicated that the electronic coupling is sensitive to conformational variations within the proline chain. ... 

A time resolution of approximately 10 ps is possible with the CFMIO method, although at such short times the mixing and chemical reaction take place simultaneously and the analysis becomes more complicated. Nonetheless, the method was used successfully in a study of the reactions of iron(III) and ruthenium(III) polypyridine complexes with several transition metal cyano compounds [3], but each experiment required approximately 300 mL of solution. The measured rate constants for electron transfer exceeded 3 x 10 M s . ... 

Owing to the great interest in photoreduction reactions, electron transfer processes involving [Co (cage)] + and polypyridine-ruthenium(II) complexes have been extensively investigated. The rate constants for the quenching process range from 2 X 10 to 1 X 10 s at 25 °C. The yields of electron transfer products... 

The kinetic data for a series of outer-sphere electron transfer reactions between the [Rh2(02CCH3)4(CH3CN)2] couple and nickel tetraaza macrocycles and iron and ruthenium tris(polypyridine) complexes in acetonitrile have been correlated in terms of the Marcus relationship, yielding a [Rh2] electron exchange rate constant of 3.0 1.7 x 10 M A somewhat smaller value of 5.3 1.3 x... 

The excited state reactions of tris(polypyridine)ruthenium complexes have been reviewed. The rate constants for the oxidative quenching of the luminescence of [ Ru(bpy)3] " and [ Ru(bpy)2(4,4 -Cl2bpy)] by the heteropolytungstate [Mn(0H)PWii039] and [Co(H20)SiW,039] ions have been measured as a... 

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