C–H⋯π synthon repetitivity in coordination compounds, established from single-crystal and powder diffraction

Abstract

Three Hg(II) complexes, [HgCl2(L)2], 1, [HgBr2(L)2], 2, and [Hg2I4(L)2], 3, containing the flexible N-(2-pyrazine)-thiophene-3-acetamide ligand (L) have been prepared and crystal structures of these compounds have been elucidated by single crystal (L, 1 and 3) and powder (2) X-ray diffraction. The crystal structures are determined mostly by N–H⋯N/O classical hydrogen bonding interactions, but in all compounds, the hydrogen atoms of thiophene ring and/or of connecting CH2 are pointed toward the adjacent thiophene rings to generate C–H⋯π synthons that participate in additional stabilization of the crystal structures.