MCET from Electron Donors to

The AE value obtained from the deviation of the g z value from the free spin value increases in order monovalent cations (M ) divalent cations (M ) trivalent cations (M ). The AE value also increases with decreasing ion radius when the oxidation state of the metal ion is the same. The same trend has been reported for 02 adsorbed on the surface of various metal oxides, which act as Lewis acids as well. The scandium ion, which has the smallest ion radius among the trivalent metal cations, gives the largest AE value.  

Electron transfer from 02 -M to electron acceptors is also coupled with the binding of M with the radical anions of electron acceptors. MCET from 02 -M to -benzoquinone (Q) can be monitored by EPR when 02 binds 

Plots of fcet versus [Sc(HMPA)3 ] for Sc(HMPA)3 -coupled electron transfer from 02 -Sc(HMPA)3 complex to Q ( ), and QIO (O) in EtCN at 298 K. 

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