Supramolecular arrays of the [Re6([μ3-Se)8]2+ core-containing clusters mediated by transition metal ions

Vapor diffusion of diethyl ether into a methanol/dichloromethane (v/v, 1: 1) solution of M(NO3)(2) (M = Cd2+, Co2+, Zn2+) and the site-differentiated solvated cluster trans-[Re-6(mu(3)-Se)(8)(PEt3)(4)(4,4'-dipyridyl)(2)](SbF6)(2) afforded supramolecular arrays featuring the [Re-6(mu(3)-Se)(8)](2+) core-containing clusters mediated by the transition metal ions. The cluster complex with two 4,4'-dipyridyl moieties can be viewed as an expanded dipyridyl ligand, serving to coordinate the transition metal ions via a pair of N-pyridyl-M dative bonds. All compounds have been characterized by microanalysis (CHN) and their solid-state structures have been established by single crystal X-ray diffraction. Two polymorphous forms (1 and 2) of the crystal of M = Cd2+ have been obtained, one of which (1) exhibits a highly porous structure, whereas the other (2) displays a wavy one-dimensional arrangement. The latter form is isostructural with the complex with Co2+ (3). In the case of Zn2+ (4), the cluster complex ligand and the mediating Zn2+ are arranged in a zigzag fashion, with an average N-pyridyl-M-N-pyridyl angle bond of 88degrees. (C) 2003 Elsevier Ltd. All rights reserved.