electrochemical reduction, pyrolitic graphite electrode, phosphate buffer (pH 4.4 and 7.1);

in ethanol T=30°C; photo trans-cis isomerisation and thermal cis-trans isomerisation of azopyridines and azopyridine-bridged crown ethers, metal ion catalysis, pH dependence; ion extraction and ion transport of metal cations across o-dichlorobenzene-t-BuOH liquid membrane; Rate constant;