title: A novel type of coordination mode of chloranilic acid leading to the formation of polymeric coordination ribbon in the series of mixed-ligand copper(II) complexes with 1,10-phenanthroline.
abstract: A series of four novel mixed-ligand complexes of copper(II) with 3,6-dichloro-2,6-dihydroxy-1,4-benzoquinone (chloranilic acid) and 1,10-phenanthroline was prepared and characterised by X-ray structure analysis and IR spectroscopy. Three complexes exhibit square-pyramidal coordination, whereas one exhibits octahedral coordination. The ligand 1,10-phenanthroline acts in a bidentate chelating mode with N,N-metal binding. The chloranilate dianion coordinates to the Cu(II) atom in a terminal bidentate ortho-quinone-like mode, forming a mononuclear complex species. However, in one structure a novel type of coordination mode of chloranilate is observed. In addition to the bidentate mode, a monodentate bridging mode through a carboxy oxygen of a symmetry-related dianion leads to the formation of polymeric coordination ribbon. The crystal packing of penta-coordinated species, in addition to hydrogen bonding, involves less common stacking interactions of chelate rings with the π-systems of the ligands.
authors.affiliation: Rudjer Bošković Institute, Bijenička 54, HR-10000 Zagreb, Croatia. kmolcano@irb.hr.
authors.forename: Krešimir
authors.initials: K
authors.lastname: Molčanov
authors.forename: Marijana
authors.initials: M
authors.lastname: Jurić
authors.forename: Biserka
authors.initials: B
authors.lastname: Kojić-Prodić