Lead(ii) complexes of bis- and tris-bidentate compartmental ligands based on pyridyl-pyrazole and pyridyl-triazole fragments: coordination networks and a discrete dimeric box

Abstract

A series of six compartmental ligands, containing two or three bidentate chelating pyridyl-triazole or pyridyl-pyrazole units connected to a central aromatic spacer, has been used to prepare Pb(II) complexes which have been structurally characterised. Five of the complexes form infinite coordination networks including a one-dimensional chain and four two-dimensional sheets comprising three examples of (6,3) nets, and one example of a (4,4) net. One of the complexes is a discrete dinuclear dimeric complex in which two bridging ligands span two metal ions in a ‘mesocate’ box-like arrangement. The Pb(II) centres show a range of coordination numbers and geometries, from distorted six-coordinate with a stereochemically active lone pair of electrons, to fairly regular eight-coordinate with a square antiprismatic geometry.