Ligands LX of the type NS2 with S-aryl substituents which incorporate the unit 2,6-bis(thiomethyl)pyridine modified with functional groups bonded to the aromatic moieties, either on the phenyl or on the pyridine, are produced. Electron-withdrawing groups, 3-chloro and 4-nitro, that reduce the pyridine basicity have been introduced. Methoxy or methoxycarbonyl substituents have been incorporated on the thiophenyl moieties. The comparative results from the reaction of these ligands with CU(ClO4)(2). 6H(2)O and [RuCl2(PPh3)(3)] have revealed that their coordination capacity has not been greatly modified as a result of the introduced groups. Complexes of general formulas [CU(LX)][ClO4](2), except for L5, and [RuCl2(LX)(PPh3)], have been obtained, respectively. The electronic characteristics of these complexes have been studied by cyclic voltammetry experiments. The structures of 2,6-bis[(2 ' -methoxycarbonyl)phenylthio-methyl]-4-nitropyridine (L5) and [RuCl2(L5)(PPh3)]. 2CCl(4) have been characterized by single-crystal X-ray diffraction methods.