The C-4h isomer of the 1,2- Nc ( 1,2- naphthalocyaninato) ligand has been efficiently isolated as a hydrated magnesium complex by the fractional crystallization from the benzene/ acetone solution after treating the crude mixture of the four isomers ( C-4h, C-s, C-2v, D-2h) with benzene. The C-4h symmetry has been confirmed by X- ray structure analysis. The central metal ion has been demetalated and subsequently converted to the Li-2 complex followed by conversion to the cobalt( II) complex. Electrochemical oxidation of the Co-III( 1,2- Nc)( CN)(2) anion prepared from the cobalt( II) complex with TPP ( tetraphenylphosphonium) has yielded a partially oxidized salt, TPP[ Co-III( 1,2- Nc- C (4h))( CN) (2)] (2). The crystal comprises slipped stacked Co-III( 1,2- Nc- C (4)h)( CN)(2) one- dimensional chains and one- dimensional arrays of TPPs. The conductivity at room temperature is 0.1 S cm(-1), and the temperature dependence is semiconducting with a small activation energy of about 0.05 eV. The positive temperature-independent value of about 60 mu V deg(-1) observed in the thermoelectric power measurements suggests that the salt is in the correlated hopping regime.