Dimeric and polymeric silver(I) saccharinato complexes of two bis(pyridine) ligands: Synthesis, structural, spectroscopic, fluorescent and thermal properties

Abstract

The reaction of silver(I) with 1,2-bis[1-(pyridin-2-yl)ethylidene]hydrazine (bpeh) and N,N-bis(pyridin-2-ylmethyl)amine (bpma) in the presence of Na(sac) (sac = saccharinate) yielded [Ag-2(sac)(2)(bpeh)] (1) and [Ag(sac)(bpma)](n) (2) with conformational chirality. Both complexes have been characterized by elemental analysis, IR, thermal analysis and X-ray single crystal diffraction. Complex 1 displays a binuclear composition, in which each silver(I) ion is bound to one monodentate sac ligand and one of the bidentate pyridylimino groups of the bpeh ligand in a distorted trigonal coordination geometry. Complex 2 is a one-dimensional helical polymer, in which silver(I) centers are bridged by tridentate bpma ligands, and each silver(I) ion is coordinated in a distorted tetrahedral geometry by one monodentate sac ligand, a bidentate pyridylamine group of one bpma ligand, and a pyridylimino group of another bpma ligand. Weak intermolecular C-H center dot center dot center dot O hydrogen bonds and C-H center dot center dot center dot pi interactions lead to assembly of 1 and 2 into threedimensional supramolecular frameworks. Spectral and thermal analysis data for 1 and 2 are in agreement with the crystal structures. In addition, both complexes in the solid state display intraligand pi-pi* fluorescence. (C) 2010 Elsevier Ltd. All rights reserved.