Cyanide-bridged manganese(II) and chloride-bridged copper(II) complexes with 2-pyridineethanol: synthesis, structural characterization and C-H⋯M interactions

Abstract

[Mn(hepH)2Ni(μ-CN)2(CN)2]n (1) and [Cu2(μ-Cl)2(μ-hep)2]n (2) (2-pyridineethanol abbreviated to hepH) have been synthesized and characterized by FT-IR and Raman spectroscopies, elemental analyses, and single-crystal X-ray diffraction. X-ray single-crystal structure analysis reveals that the structures of 1 and 2 consist of 1-D infinite chains. The coordination environment of Mn(II) was identified as distorted octahedral, whereas Ni(II) has a square planar geometry in 1. Each Cu(II) in 2 adopts a distorted square pyramidal geometry in which the basal plane is constructed by oxygen and nitrogen atoms from hep and a bridging chloride ligand, respectively, and the apical position is occupied by the other chloride. The 1-D chains in 1 and 2 are extended into a 2-D supramolecular network by O−H⋯N and weak C−H⋯Cl hydrogen bonds, respectively. Adjacent 2-D layers are further connected by C−H⋯M interactions resulting in the formation of 3-D supramolecular networks. The most remarkable properties of complexes are the presence of close C–H⋯M interactions with distance values of 2.58 and 2.93 Å between H⋯Ni and H⋯Cu, respectively. The H⋯Ni interaction distance is shorter than the corresponding values of other tetracyanonickelate(II) complexes.