Electrochemical study of thermodynamics and kinetics of the cis-trans isomerization of dicarbonylbis[1,2-bis(diphenylphosphino)ethane]molybdenum and -tungsten complexes and their cations

Infrared Spectroelectrochemistry

“…The more stable forms are the cis M 0 and trans M I species. 17,18 The n(CO) bands are a particularly useful probe of the chemistry since a shift in wave number is indicative of a change in the electron richness of the metal and the stereochemistry is flagged by the presence of one (trans) or two (cis) IR-active bands. The reduction of trans-[Cr(dppm) 2 (CO) 2 ] 1 (dppm ¼ Ph 2 PCH 2 PPh 2 ) in an external reflectance SEC experiment is shown in Figure 1.5.…”

Solution electron-transfer reactions in organic and organometallic electrochemistry

“…As mentioned above, the SET reaction has little influence and could be neglected in the analysis. 157 Some of the most dramatic effects in the square scheme are encountered when B is more difficult to reduce than A (E°b,b--E°AjA-< 0). In this case, at the potential where A is reduced, the B" formed from A" can be oxidized to B, either at the electrode or via SET reaction 26.…”

Electron-Transfer-Induced Geometrical Isomerization of the Dinitrile Complexescis-[Re(NCR)2(Ph2PCH2CH2PPh2)2][BF4] (R = Aryl, Alkyl): Rates, Mechanism, and Ligand Effects

“…The relative stability and the oxidation potential of octahedral-type geometrical isomers depend on their electronic count, − although steric factors 18 and the electron donor/acceptor character of the ligands 20 and the metal 18 also play a significant role. Some theoretical calculations 6-8 and semiempirical predictions have been reported, and such behavior can be of significance in bioinorganic processes .…”

“…Most of the studies have been performed on single-electron-transfer processes of carbonyl complexes. − Conflicting situations have been recognized even for closely related complexes . Therefore, the investigation should be extended to systems presenting a variety of ligands with different electronic and stereochemical properties, as well as to processes which require the transfer of more than one electron, and some of our complexes with nitrogenase substrates 23 appear to be particular promising.…”