Reactivity of thiazolidine-2-thione towards CuI/CuII: Synthesis and structures of [3-(2-thiazolin-2-yl)thiazolidine-2-thione]copper(I) bromide and [bis(2,2′-bipyridine)nitratocopper(II)] nitrate

Abstract

Thiazolidine-2-thione (L1, NC3H5S2) reacted with copper(I) bromide in CH3CN under aerobic conditions and transformed through C–S bond cleavage into 3-(2-thiazolin-2-yl)thiazolidine-2-thione (L2, C3H4S2N-C3H4SN). This thio-ligand L2 with CuI ion yielded a three coordinate complex, [3-(2-Thiazolin-2-yl)thiazolidine-2-thione]copper(I)bromide 1a which crystallized in the triclinic system with the space group P1 as reported earlier. Treatment of 1a with bis(diphenylphosphino)methane (dppm) in dichloromethane also formed [3-(2-thiazolin-2-yl)thiazolidine-2-thione]copper(I) bromide 1b but it crystallized into the triclinic system with a new space group, P-1: 296(2) K, a, 7.3890(19); b, 8.473(2); c, 9.491(2) Å; α, 70.273(5); β, 67.170(5); γ, 84.949(5)∘; R, 6.79%. Reactions of copper(II) nitrate with thiazolidine-2-thione followed by the addition of 2,2′-bipyridine or with 2,2′-bipyridine first followed by the addition of thiazolidine-2-thione, gave blue crystals in both the cases. The x-ray crystallography revealed stoichiometry of the complex formed as: [Cu(κ 2-N,N′-bipy)2(κ 1-ONO2)](NO3)2, which crystallized in monoclinic crystal system with space group, P21/n(14). Crystal data: 173(2) K, a, 11.318(1), b, 12.160(1), c, 14.967(1) Å; β = 98.01(1)∘, R, 3.99%; 296(2) K, a, 11.340(5), b, 12.249(5), c, 15.065(6) Å; β = 98.04(2)∘, R, 4.09%. Thiazolidine-2-thione with copper(I) bromide in CH3CN under aerobic conditions yielded red brown crystals which on treatment with bis(diphenylphosphino)methane in dichloromethane formed [3-(2-thiazolin-2-yl)thiazolidine-2-thione]copper(I) bromide which crystallized into triclinic system with space group, P-1.