Syntheses, structures and properties of homo- and heterobimetallic complexes of the type [Zn(tren)NCS]2[M(NCS)4] [tren = tris(2-aminoethyl)amine; M = Zn, Cu]

A 2:2:1:6 molar ratio of Zn(ClO4)(2)center dot 6H(2)O, tris(2-aminoethyl)amine (tren), Zn(ClO4)(2)center dot 6H(2)O/Cu(ClO4)(2)center dot 6H(2)O and NH4NCS in methanol-water solution mixtures affords homo-/heterobimetallic compounds of the type [Zn(tren)NCS](2)[M(NCS)(4)](M = Zn, 1; M = Cu, 2) which have been characterized using microanalytical, spectroscopic, magnetic and other physicochemical results. The structures of the compounds are determined by X-ray diffraction measurements. Structural analyses reveal that 1 and 2 are isomorphous and consist of two discrete [Zn(tren)NCS](+) cations and a [M(NCS)(4)](2-) (M = Zn/Cu) anion. Zinc(II) centers in the [Zn(tren)NCS](+) units adopt distorted trigonal bipyramidal geometry with ZnN5 chromophores coordinated through four N atoms of tren and one N atom of terminal thiocyanate. Each metal(II) center in [M(NCS)(4)](2-) has a distorted tetrahedral coordination environment with an MN4 chromophore ligated by four N atoms of the terminal thiocyanates. In solid state, doubly N-H center dot center dot center dot S hydrogen bonded 1D chains of [Zn(tren)NCS](+) cations are interconnected by tetrahedral [Zn(NCS)(4)](2-)/[Cu(NCS)(4)](2-) anions through cooperative N-H center dot center dot center dot S and N-H center dot center dot center dot N (in 1) and N-H center dot center dot center dot S and C-H center dot center dot center dot S (in 2) hydrogen bonds resulting in 3D network structures. Establishment of such networks seems to be aiding the crystallization. (C) 2010 Elsevier B.V. All rights reserved.