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

(Acetonitrile-1κN)[μ-1H-benzimidazole-2(3H)-thione-1:2κ2S:S][1H-benzimidazole-2(3H)-thione-2κS]bis­(μ-1,1-dioxo-1λ6,2-benzothia­zole-3-thiol­ato)-1:2κ2S3:N;1:2κ2S3:S3-dicopper(I)(Cu—Cu), [Cu2(C7H4NO2S2)2(C7H6N2S)2(CH3CN)] or [Cu2(tsac)2(Sbim)2(CH3CN)] [tsac is thio­saccharinate 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 mol­ecule, two tsac anions and one neutral Sbim ligand bind the metals. One anion bridges via the endocyclic N and exocyclic S atoms (μ-S:N). The other anion and one of the mercaptobenzimidazole mol­ecules bridge the metals through their exocyclic S atoms (μ-S:S). The second Sbim ligand coordinates in a monodentate fashion (κS) to one Cu atom, while an acetonitrile mol­ecule coordinates to the other Cu atom. The CuI—CuI distance [2.6286 (6) A] can be considered a strong `cuprophilic' inter­action. In the case of [μ-1H-benzimidazole-2(3H)-thione-1:2κ2S:S]bis­[1H-benzimidazole-2(3H)-thione]-1κS;2κS-bis­(μ-1,1-dioxo-1λ6,2-benzo­thia­zole-3-thiol­ato)-1:2κ2S3:N;1:2κ2S3:S3-dicopper(I)(Cu—Cu), [Cu2(C7H4NO2S2)2(C7H6N2S)3] or [Cu2(tsac)2(Sbim)3], (II), the acetonitrile mol­ecule is substituted by an additional Sbim ligand, which binds one Cu atom via the exocylic S atom. In this case, the CuI—CuI distance is 2.6068 (11) A.