engleski

Stacking of metal chelating rings with π-systems in mononuclear complexes of copper(II) with 3, 6- dichloro-2, 5-dihydroxy-1, 4-benzoquinone (chloranilic acid) and 2, 2'-bipyridine ligands

A series of four novel mononuclear complexes of copper(II) with chloranilic acid and 2, 2'- bipyridine was prepared and structurally characterised by X-ray structure analysis and IR spectroscopy. The complexes exhibit square-planar, square-pyramidal and octahedral coordination. Chloranilate dianion coordinates CuII atom in a terminal bidentate o-quinone-like mode forming mononuclear complex species. Crystal packings of the aqua complex and the complexes with crystal water molecules are defined by hydrogen bonds. However, significant contributions are through interactions involving five-membered chelate rings with both type of ligands and intermolecular π- systems (bipyridine and chloranilate rings). The crystal packing of complex with a square planar CuII coordination is dominated by interactions of chelate rings with π-delocalised bonds and intermolecular π-systems. The occurrence of dimorphism could be related to different type of these interactions in stacks. Crystal packings of the octahedral complexes of mono- and dihydrate solvates reveal 3D-networks with pores occupied by non-coordinated bipyridine molecules.

copper(II); chloranilic acid; coordination chemistry; crystal structure

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