Design and structural analysis of metallamacrocycles based on a combination of ethylene glycol bearing pyridine units with zinc, cobalt and mercury

In the presence Of MX2 salts, ligand 1 (in a M/L ratio of 2:2, M = Zn, Hg, Co, X = CI or I), based on the ethylene glycol fragment bearing two pyridine units as monodentate coordination sites, leads to isostructural square-shaped neutral metallamacrocycles as demonstrated by X-ray diffraction on single crystals. For all dinuclear complexes generated, the dicationic metal centre adopts a distorted tetrahedral coordination geometry and its coordination sphere is composed of the X2N2 set of coordinating atoms. For all complexes, the parallel packing of the cyclic structures generates channels which are occupied by solvent molecules. The solvent molecules, which behave as substrates, are positioned within the cavity of the metallamacrocycles. Control of the dimension of the macrocycles, by varying the size of the connecting metal centre, has also been demonstrated. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.