Electrocatalysis in organized assemblies. Part VII. Electrochemistry and electrocatalysis with vitamin B12 in an AOT water-in-oil microemulsion

摘要: Vitamin B{sub 12a} solubilized in water pools of highly resistive water-in-oil (w/o) microemulsions 0.2 M Aerosol OT (AOT, bis(2-ethylhexyl) sulfosuccinate)/4 water/isooctane gave separate reductions base-on cob(III)alamine to cob(II)alamine (E{sub 1/2} = {minus}0.03 V vs SCE) and base-off cob(I)alamine {minus} 0.87 V). Diffusion coefficients suggested that vitamin 12} induces the formation surfactant aggregates w/o are larger than solute-free systems. Relative reactivities toward three oil-soluble alkyl vicinal dihalides by electrochemically generated cob(I) alamine were modified microemulsion compared isotropic water-acetonitrile. Changes relative reactivity not explained simple partition dibromides between isooctane suggest specific interactions with or significant reaction bulk phase.