Syntheses, crystal structures and Hirshfeld surface analyses of bis-(2-mercaptobenzimidazole)-bromo- and iodo-copper(I) complexes.

The title complexes, bromidobis(2,3-dihydro-1H-1,3-benzodiazole-2-thi-one)copper(I), [CuBr(C7H6N2S)2] (1), and bis(2,3-dihydro-1H-1,3-benzodiazole-2-thione)iodidocopper(I) acetone monosolvate, [CuI(C7H6N2S)2]·CH3COCH3 (2), were prepared by the reaction of copper(I) bromide/iodide with 2-mercaptobenzimidazole. Both complexes have mononuclear structures with the copper atom coordinated by two 2-mercaptobenzimidazole mol-ecules via their S atoms and one halide atom in an approximate trigonal-planar arrangement. In their extended structures, N-H⋯S hydrogen bonds and π-π contacts are found in both complexes; as a result of the acetone solvent mol-ecule in (2), N-H⋯O contacts are also observed. Hirshfeld surface analyses were carried out to aid in the visualization of these inter-actions, which showed that H⋯H contacts contribute 34.6% for (1) and 34.1% for (2) to the overall surface, followed by contributions from H⋯S/S⋯H, H⋯C/C⋯H and C⋯C contacts, respectively. As expected, H⋯O/O⋯H contacts are observed only in (2). The IR and 1H and 13C NMR spectra of (1) and (2) are described.