A New Approach to Novel Cluster Compounds of Lead(II) Phosphonates

Abstract

AbstractFive new lead(II) sulfonate‐phosphonates, namely [Pb3(L)2(H2O)2]·4H2O (1), [Pb(HL)(phen)]·H2O (2), [Pb6(L)4(phen)8]·3H2O (3), [Pb6(L)4(phen)10]·2H2O (4), and [Pb6(L)4(4,4′‐bipy)(H2O)2]·2H2O (5; H3L = m‐HO3S‐C6H4‐PO3H2, phen = 1,10‐phenanthroline, 4,4′‐bipy = 4,4′‐bipyridine) have been prepared and structurally characterized. Compound 1 features a novel 3D framework in which 1D chains of Pb3O4 cluster units are further bridged by sulfonate‐phosphonate ligands, whereas compound 2 features a layer structure in which 1D chains of Pb2O4 clusters are further bridged by sulfonate‐phosphonate ligands. Compounds 3 and 4 represent the first zero‐dimensional lead(II) phosphonates and feature novel isolated hexanuclear lead(II) clusters in which six PbII ions are bridged by two tetradentate and two pentadentate phosphonate groups. Compound 5 features a 3D framework that is similar to that in compound 1 despite the different coordination modes for some sulfonate groups of the ligands. The main difference is that an aqua ligand in compound 1 is replaced by a nitrogen atom of the 4,4′‐bipy ligand, which results in the splitting of the large cavities in compound 1 into two small apertures in compound 5. Compounds 1 and 5 exhibit strong broad blue fluorescent emission bands at 398 and 420 nm, respectively.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)