Synthesis and electrochemistry of (5Z,5′Z)-2,2′-(alkane-α,ω-diyldisulfanyldiyl)-bis(5-(2-pyridylmethylene)-3,5-dihydro-4H-imidazol-4-one) complexes with cobalt(II) chloride

A series of S-alkylated 2-thiohydantoin derivatives containing two 5-(2-pyridylmethylene)-2-sulfanyl-3,5-dihydro-4H-imidazol-4-one moieties linked through a polymethylene bridge with different numbers of carbon atoms was synthesized for the first time. These compounds were obtained by the alkylation of 3-phenyl-5-(2-pyridylmethylene)-2-thiohydantoin or 3-methyl-5-(2-pyridylmethylene)-2-thiohydantoin with different α,ω-dibromoalkanes in acetone or DMF in the presence of potassium carbonate. Complexes of these compounds (L) with CoCl2 were synthesized. In all cases, the complexes L(CoCl2)2 were formed regardless of the ratio of L and inorganic salt introduced into the reaction. According to electronic spectroscopic data, the cobalt atom in the complexes has a tetrahedral coordination environment. The synthesized ligands and complexes were electrochemically studied by cyclic voltammetry.