Synthesis, crystal structures, spectroscopic and thermal properties of silver(I) saccharinate complexes with N-donor ligands

Abstract

The synthesis, spectroscopic and thermal properties and X-ray structures of four silver(I) saccharinate complexes with N-donor ligands, [Ag(sac)(edmen)] (1), [Ag(sac)(teten)] (2), [Ag-2(sac)(2)(o-bix)(2)] (3) and [Ag(sac)(dpa)] (4) (edmen = N-ethyl-N',N'-dimethylethylenediamine, teten = N,N,N',N'-tetrakis(2-hydroxyethyl)ethylenediamine, o-bix = 1,2-bis(imidazole-1-ylmethyl)benzene and dpa = 2,2'-dipyridylamine) are described. In complex 1, the Ag(I) ion is coordinated by two N atoms from edmen and one N atom from sac ligand, forming a slightly distorted Y-shaped AgN3 arrangement. In complex 2, the Ag(I) is four coordinated by N-bonded sac and tridentate teten ligands, exhibiting a seesaw AgN3O geometry. A crystallographically independent Ag(I) ion in 3 is surrounded with a T-shaped geometry by two N atoms from o-bix ligand and one N atom from one sac ligand, and the Ag center dot center dot center dot Ag separation is 3.338 angstrom. In complex 4, the Ag1 ion is coordinated by three nitrogen atoms from sac and dpa ligands to form a distorted Y-shaped geometry. The dpa ligand behaves as a bidentate ligand, forming a six-membered chelate ring, while the sac ligand is N-coordinated. The most striking feature of complexes 1 and 2 is the presence of both intra- and intermolecular C-H center dot center dot center dot Ag hydrogen-bonding interactions. Crystal packing of complexes is achieved by the hydrogen bonds, intra- and/or intermolecular C-H center dot center dot center dot pi, weak pi center dot center dot center dot pi and Ag center dot center dot center dot pi interactions to generate a three-dimensional supramolecular network. The photoluminescence spectrum shows that 4 displays a red-shift emission in the solid state at room temperature. (c) 2012 Elsevier Ltd. All rights reserved.