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

Abstract

(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 bridgesviathe 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 Cu^I—Cu^Idistance [2.6286 (6) Å] 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 atomviathe exocylic S atom. In this case, the Cu^I—Cu^Idistance is 2.6068 (11) Å.