Solvent and counter ion effects in bis(imidazole) dinuclear heterometallacyclic complexes of gold(I): Some considerations of porosity

Cyclic 2:2 complexes of Au(1) and bitmb [1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene] were prepared and the structures of [Au(2)(mu-bitmb)(2)](BF(4))(2)center dot 2CH(3)CN (1.2CH(3)CN), [Au(2)(mu-bitmb)(2)](BF(4))(2)center dot 2CH(2)Cl(2) (1.2CH(2)Cl(2)) and [Au(2)(mu-bitmb)(2)](CF(3)SO(3))(2).2CH(2)Cl(2) (2.2CH(2)Cl(2)) were determined by single crystal X-ray diffraction. The frameworks of the compounds consist of dicationic rectangular heterometallacycles linked by aurophilic interactions along the b axis and edge-to-face C H center dot center dot center dot pi contacts. The latter expand the structures in zigzag fashion along the a axis leading to a 3D assembly. Interactions between the counterions and imidazole rings are also present in all structures. When crystals of 2.2CH(2)Cl(2) are subjected to a dynamic vacuum at 90 degrees C remarkably only 1 mol equivalent of CH(2)Cl(2) is removed, but without loss of crystallinity, affording the structure of 2.CH(2)Cl(2). (C) 2010 Elsevier B.V. All rights reserved.