Molecular architectures derived from metal ions and the flexible 3,3′-bipyridine ligand: Unexpected dimer with Hg(II)

Abstract

The flexible ditopic ligand 3, 3′-bipyridine (3, 3′-bpy) has been reacted with a series of transition metal species (Ag+, Hg 2+, cis-a2M2+ (a = NH3 or a 2 = en; M = Pt, Pd), trans-a2Pt2+ (a = NH 3)) in an attempt to produce discrete cyclic constructs. While Ag+ gave a polymeric structure {[Ag(3, 3′-bpy)](ClO 4)·H2O}n (1), with all other metal entities cyclic structures were formed. Interestingly, Hg(CH3COO) 2 produced a dinuclear complex [Hg(3, 3′-bpy)(CH 3COO)2]2·3H2O (2), in which the two 3, 3′-bpy ligands adopt a cis-orientation of the coordinating pyridyl entities. With cis-(NH3)2 Pt2+, a cyclic complex 4 was isolated in crystalline form which, according to HRMS, is a trimer. With trans-(NH3)2Pt2+, different species are formed according to 1H NMR spectroscopy, the nature of which was not established. Copyright © 2010 Anupam Khutia et al.