in dichloromethane Electrolysis; controlled-potential electrolysis at Hg electrode in CH2Cl2 at 22°C; electrochemical and spectrophotometrical monitoring; Hg complex identified by comparison with authentic sample;

oxygen in not given Electrolysis; electrochemical reduction of Co-complexes at 20°C in the presence of ligand at mercury-pool electrode, subsequent aerial oxidation; detected by (59)Co NMR spectra;