Innersphere electron transfer

The fourth OA mechanism involves an innersphere electron transfer reaction between the organometallic compound and R-X, leading to the one-electron oxidized complex R radical cage. The radical cage then undergoes... 

Electrocatalytic oxidation through a charge transfer-complex with innersphere electron transfer ... 

These kinetics data are consistent with a preequilibrium dissociation of dmf from the molybdenum center to form a reactive five-coordinate species that rapidly reduces the Fe(III) center via an inner sphere (halogen transfer) reaction. Other one-electron atom transfer reactions are known in oxo-molybdenum chemistry (262). An innersphere (atom transfer) mechanism is not a viable model for intramolecular transfer in sulfite oxidase because in the enzyme the Mo and Fe centers are almost certainly held too far apart by the protein framework. Moreover, the 65-type heme center of sulfite oxidase is six-coordinate with axial histidine ligands from the protein and hence cannot participate in atom transfer reactions. 

The effect of ionic strength and dielectric constant of the medium on the rate explains qualitatively the reaction between two negatively charged ions, as seen in Scheme 1. The moderate AH and AS values are favorable for electron transfer reaction. The negative value of AS suggests that the intermediate complex is more ordered than the reactants [11]. The observed modest enthalpy of activation and a higher-rate constant for the slow step indicate that the oxidation presumably occurs via an innersphere mechanism. This conclusion is supported by earlier observations [12]. 

Oxidation of alcohols at the expense of photoreduction of Cr (VI) was initially interpreted in terms of the photochemical reactivity of chromate(VI) esters, but time-resolved spectroscopic studies 253) proved that the photoreaction mode depends on the bond strength between chromate and secondary alcohol. In the case of the strong bond, innersphere transfer of two electrons was recorded (Fig. 3) ... 

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