Coordination geometry isomerism induced by N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl, C-H center dot center dot center dot N, C-H center dot center dot center dot pi and pi center dot center dot center dot pi su

摘要

Reaction of HgCl2 with trans-(+/-)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl)pyridine (L1) and cis-(+/-)-(phenyl(2,4,5-tri(pyridin-2-yl)-4,5-dihydroimidazol- 1-yl)methanone (L2) gives mononuclear complexes, 1 and 2. In these complexes L1 and L2 behave as tridentate and bidentate chelating ligands, giving distorted trigonal bipyramidal and tetrahedral coordination geometries, respectively. X-ray diffraction studies revealed a series of N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl, C-H center dot center dot center dot N and C-H center dot center dot center dot pi interactions in 1 giving a 3D network, and N-H center dot center dot center dot Cl, C-H center dot center dot center dot Cl, C-H center dot center dot center dot pi and pi center dot center dot center dot pi interactions in 2 giving a 2D network in the crystal lattice. Since both ligands should have a similar binding capacity to the mercury ions, the variations observed for coordination number and geometry should be a consequence of supramolecular stabilizing effects. (c) 2007 Elsevier B.V. All rights reserved.