Crystal Structures of Triazine-3-thione Derivatives by Reaction with Copper and Cobalt Salts

The reaction of 5-methoxy-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]triazine-3-thione L¹H₂OCH₃ with copper(II) chloride leads to the formation of an organic molecule L² containing two triazine rings linked by a new S−S bond. A binuclear copper(II) complex, 1, containing L¹ is also isolated. The reaction of L¹H₂OCH₃ with copper(I) chloride yields a hexanuclear cluster of copper(I), 2, in which the copper atoms form a distorted octahedron with the ligand L¹ acting as an NS chelate and sulfur bridge, giving to the copper ion a trigonal geometry by one N and two S atoms. In any reaction of the disulfide L² with metal salts, complexes containing this molecule are isolated. Reactions with copper(I) and copper(II) chloride and nickel(II) and cadmium(II) nitrate produce the S−S bond cleavage, giving complexes containing the triazine L¹ behaving as the NS anion, which show spectroscopic characteristics identical with those formed by reaction with L¹H₂OCH₃. However, the reaction with cobalt(II) nitrate gives a low-spin octahedral cobalt(III) complex, in which an asymmetric rupture of the disulfide L² has been produced, giving an unexpected complex with a new ligand and keeping the S−S bond.