The conformations of two copper(I) complexes of 1H-benzimidazole- 2(3H)-thione and thiosaccharinate

Abstract

(Acetonitrile-1N)[-1H-benzimidazole-2(3H)-thione-1:2 2 S:S][1H-benzimidazole-2(3H)-thione-2S]bis-(-1,1-dioxo-1 6,2-benzothia- zole-3-thiol-ato)-1:2 2 S 3:N;1:2 2 S 3:S 3-dicopper(I)(Cu - Cu), [Cu2(C7H4NO2S2)2(C7H6N2S) 2(CH3CN)] or [Cu2(tsac)2(Sbim)2(CH3CN)] [tsac is thio-saccharinate and Sbim is 1H-benzimidazole-2(3H)-thione], (I), is a new copper(I) compound that consists of a triply bridged dinuclear Cu - Cu unit. In the complex mol-ecule, two tsac anions and one neutral Sbim ligand bind the metals. One anion bridges via the endocyclic N and exocyclic S atoms (-S:N). The other anion and one of the mercaptobenzimidazole mol-ecules bridge the metals through their exocyclic S atoms (-S:S). The second Sbim ligand coordinates in a monodentate fashion (S) to one Cu atom, while an acetonitrile mol-ecule coordinates to the other Cu atom. The Cu I - Cu I distance [2.6286 (6) Å] can be considered a strong cuprophilic inter-action. In the case of [-1H-benzimidazole-2(3H)-thione-1:2 2 S:S]bis-[1H-benzimidazole-2(3H)- thione]-1S;2S-bis-(-1,1-dioxo-1 6,2-benzo-thia-zole-3-thiol-ato)-1: 2 2 S 3:N;1:2 2 S 3:S 3-dicopper(I)(Cu - Cu), [Cu2(C7H4NO2S2)2(C7H6N2S)3] or [Cu2(tsac)2(Sbim)3], (II), the acetonitrile mol-ecule is substituted by an additional Sbim ligand, which binds one Cu atom via the exocylic S atom. In this case, the Cu I - Cu I distance is 2.6068 (11) Å.