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

Abstract

508Our results of studying Ni(II) and Cu(II) bis(thio semicarbazide) complexes with different anions [1,2] and available literature data on the structures of anal ogous compounds [3][4][5][6][7][8][9] have revealed a considerable variety of the structures of these compounds in spite of a rather stereotypic structure of the complex cation.The [М(TSC) 2 ] 2+ cation (M = Ni(II), Cu(II)) in these compounds has a square of near square shape owing to the bidentate chelating (N,S) coordination of the TSC ligand. Sometimes, the metal coordination sphere is completed to tetragonal pyramidal or tetra gonal bipyramidal by axial atoms at elongated dis tances. The metal atom is in the plane of the coordina tion square. The TSC ligand is planar, but its plane can be somewhat out of the coordination plane. In this case, there is a small bend along the N···S line (an envelope conformation). The linear and angular parameters of the coordination polyhedron are almost identical for the same metal but are somewhat differ ent for Ni(II) and Cu(II).It is worth noting that a considerable role in crystal structure is played by the anion mainly involved in for mation of the supramolecular crystal architecture.The anion of multifunctional 5 sulfosalicylic acid (H 3 SSal) used in this work favors the formation of numerous hydrogen bonds, which can be combined in cyclic fragments capable of strengthening of the struc ture due to π-π stacking interaction.Depending on the degree of deprotonation of H 3 SSal, there are H 2 SSal -, HSSal 2-, and SSal 3-anions. Incomplete deprotonation is possible for dif ferent combination of atoms in [H 3n SSal] n -1 .In this paper, we report the results of X ray crystal lographic analysis of [Cu(TSC) 2 ](H 2 SSal) 2 (I), con taining the monodeprotonated anion. EXPERIMENTAL Synthesis of I (С 8 H 10 Cu 0.5 N 3 O 6 S 2 ). In separate beakers, solutions of 1.71 g CuCl 2 ⋅ 2H 2 O (0.01 mol) and 0.4 g NaOH (0.01 mol) in 5 mL water were pre pared and then poured together. The resulting precip itate was filtered off on a paper filter, washed with water, and added portionwise to a solution of 2.18 g 5 sulfosalicylic acid (0.01 mol) in 5 mL water. To the resulting solution of copper(II) 5 sulfosalicylate, 1.82 g (0.02 mol) of dry finely ground thiosemicarbazide was added, which was accompanied by formation of a brown precipitate. It was stirred for 15 min with a mag netic stirrer, filtered off through a Schott filter, washed with water, and dried at 50°С to a constant weight.Crystals suitable for X ray crystallography were obtained by recrystallization of the powder product from water.The IR absorption spectra were recorded as KBr pel lets on a Shimadzu FTIR 8400S spectrophotometer.Abstract-The compound [Cu(TSC) 2 ](H 2 SSal) 2 (I) has been synthesized (TSC is thiosemicarbazide, H 3 SSal 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) Å 3 , Z = 2, ...