88326-31-2Relevant academic research and scientific papers
Study of substituent effects, isomerization and cross redox reactions associated with electrochemical oxidation of Mo(CO)3P3 systems
Bond,Carr,Colton
, p. 541 - 548 (2008/10/08)
Homogeneous and heterogeneous aspects of the redox couple [Mo(CO)3P3]+/0 (P = monodentate phosphorus ligand) have been examined by polarographic, voltammetric, and spectroscopic methods in dichloromethane solution. The tricarbonyl compounds in each oxidation state can exist in both facial (fac+, fac0) and meridional (mer+, mer0) forms. The cyclic voltammograms at room temperature often showed the form of quasi-reversible couples; however, they did not fit theoretical models for simple electron transfer. With use of low temperatures and a variety of scan rates, it was deduced that the electrode processes could be explained in terms of parts of the square reaction scheme fac0 ? fac+ + e- (upward harpoon with barb leftwards) + ? (upward harpoon with barb leftwards) + ? mer0 ? mer+ + e- and the cross redox reaction. fac+ + mer0 ?κ fac0 + mer+ At low temperatures it was possible to calculate E°(fac+/0) and E°(mer+/0) and hence calculate the equilibrium constant, K, for the cross redox reaction. Both K and the E° values showed a very large dependence on the nature of the phosphorus ligand. For fac-Mo(CO)3P3, a satisfactory linear correlation between carbon-13 NMR chemical shift (δ(13C)) of the carbonyl ligands and E°(fac+/0) was obtained, but similar correlations were not observed between E°(fac+/0) and either δ(31P) of the phosphorus ligands or δ(95Mo) of the central molybdenum atom.
