Spectroscopic and electrochemical properties of mixed-ligand cyclopalladinized complexes of deprotonated forms of 2-(2-thienyl)pyridine and 2-phenylpyridine with 1,10-phenantroline and its 1,4-diazine derivatives

A comparative study of [Pd((NC)-C-boolean AND)((NN)-N-boolean AND)](+) complexes {((NC)-C-boolean AND)(-) are deprotonated forms of 2-phenylpyridine and 2-(2-thienyl)pyridine and ((NN)-N-boolean AND) is 1,10-phenantroline, dipyrido[f,h]quinoxaline, dipyrido[a,c]phenazine or 6,7-dicyanodibenzo[f,h]quinoxaline} was carried out by the methods of H-1 NMR, electronic absorption and emission spectroscopy, and cyclic voltammetry. Optical and electrochemical properties of dipyrido-substituted 1,4-diazines are conditioned by the electron transfer involving pi* orbitals localized on weakly interacting phenantroline (pi(*)(phen)) and diazne (pi(*)(diaz)) components.