0D and 1D copper(II) coordination polymers based on 2-methyl-1H-imidazole: Structural, vibrational and magnetic characterizations

Bis(2-methyl-1H-imidazolium)tetrachlorocuprate(II), monomer 1, and 2-methyl-1H-imidazoliumaquatrichlorocuprate(II), polymer 2, were synthesized and their crystal structures were determined. N/C-H center dot center dot center dot Cl hydrogen bonds stabilize the monomeric structure of the tetrachlorocuprate(II) anion together with the steric demand of the relatively large 2-methylimidazolium ions in the crystal lattice of 1. Conversely, in 2, O-H center dot center dot center dot Cl hydrogen bonds reduce the electron density on the chloride ions in such a way the electron repulsions decrease and coordination spheres with more ligands develop. Obviously, water may be a successful competitor for ligand sites in 2 as well. In 2, The square-pyramidal structural parts [CuCl3(H2O)](-) condense into polymeric chains of -CuCl2(H2O)-mu-Cl-CuCl2(H2O)-mu-Cl-CuCl2(H2O)-. In both complexes, aromatic amines linked through pi...pi interactions, are intercalated between the inorganic layers to provide a new structure topology that gathers between supramolecular and lamellar aspects. Magnetic measurements indicate the presence of weak antiferromagnetic interactions in compound 2. (C) 2016 Elsevier B. V. All rights reserved.