ELECTROLYSIS IN THE PRESENCE OF ULTRASOUND - CELL GEOMETRIES FOR THE APPLICATION OF EXTREME RATES OF MASS-TRANSFER IN ELECTROSYNTHESIS

Two types of sonoelectrochemical reactors for preparative synthetic wo rk are suggested and characterized by their performance in the reversi ble one electron reduction of cobalticenium cations;in acetonitrile so lution, The dominant effect of ultrasound is to strongly agitate the l iquid,phase and the corresponding parameters (mass transport coefficie nts) for the transport at the electrode surface are reported, An upper limit for ultrasound induced mass transport at macroelectrodes an ord er of,magnitude beyond that achieved in conventional electrolysis is d escribed, Further, for a synthetic Scale reaction, the reductive ring I opening of the a,B-epoxyketone isophorone oxide to yield the corresp onding beta-hydroxyketope, an improved current efficiency (3 F for a d irect two electron reduction)and clean conversion (yields up to 80% is olated) are demonstrated, The extremely high rates of mass transport a chieved in the presence of ultrasound considerably enhance the perform ance and current efficiency in electrosynthesis by selectively increas ing the rates of the mass transport controlled processes.