Synthesis and crystal structure of a copper(II) 5-sulfosalicylate complex with thiosemicarbazide

The compound [Cu(TSC)2](H2SSal)2 (I) has been synthesized (TSC is thiosemicarbazide, H3SSal is 5-sulfosalicylic acid) and studied by IR spectroscopy and X-ray crystallography. The crystals of I are triclinic: a = 6.728(2) Å, b = 7.772(1)Å, c = 11.600(6)Å, α = 88.60°, β = 86.68(3)°, γ = 79.22(4)°, V = 594.8(4)Å3, Z = 2, space group $P\bar 1$. The structural units of the crystal are the centrosymmetric [Cu(TSC)2]2+ cation, in which the Cu atom is in a square-planar coordination formed by the bidentate chelating (N,S) TSC ligands, and (H2SSal)− anions (Cu(1)-N(3), 2.013(3) Å; Cu(1)-S(1), 2.275(1) Å). The coordination polyhedron of the Cu(1) atom is completed to a prolate tetragonal bipyramid (4 + 2) by Cu-O bonds (2.810(3) Å) of the sulfate moieties of both anions, which form together with hydrogen bonds the [Cu(TSC)2(H2SSal)2] supermolecule. The complex cations are packed in layers and alternate with anion-containing layers. Hydrogen bonding and π−π stacking interactions are responsible for formation of supramolecular layer ensembles.