Mononuclear nickel complexes assembled into two-dimensional networks via hydrogen bonds and π-π stacking interactions

Three monomeric nickel complexes [Ni(bipy)(O2CMe)(2)(H2O)(2)] 1 (bipy = 2,2'-bipyridine), [Ni(dmbipy)-(O2CMe)(2)(H2O)(2)] 2 (dmbipy = 4,4'-dimethyl-2,2'-bipyridine) and [Ni(phen)(O2CMe)(2)(H2O)(2)] . 0.5H(2)O 3 (phen = 1,10-phenanthroline) have been synthesized and characterized by single-crystal X-ray diffraction methods. In complexes 1 and 2 the molecules are self-assembled via double intermolecular hydrogen bonds to form one-dimensional infinite zigzag chains, which are stacked next to each other through the diimine aromatic rings in a zipper-like fashion, giving a novel two-dimensional co-operating structure. In 3 the molecule is linked by a hydrogen bond to form a one-dimensional chain, which is further associated with another adjacent chain via double hydrogen bonds forming a double chain. These double chains are intercalated to each other through the pi-pi interaction giving a novel two-dimensional structure.