catena-Poly[[tetra-μ3-isonicotinato-μ3-oxalato-μ2-oxalato-disamarium(III)disilver(I)] dihydrate]

Abstract

In the title compound, {[AgSm(C6H4NO2)2(C2O4)]·H2O}n, the asymmetric unit contains one SmIII ion, one AgI ion, two unique isonicotinate (ina) ligands, two half oxalate (ox) ligands (one on an inversion centre, the other on a twofold axis) and one uncoordinated water molecule. The central SmIII ion is nine-coordinated by four O-donor atoms from separate bidentate bridging ox ligands and five O-donor atoms from the two ina ligands (both bidentate) and a symmetry-related ina ligand [Sm—O = 2.389 (4)–2.791 (4) Å], giving a distorted monocapped square antiprismatic geometry. The AgI ion is three-coordinated in a T-shaped geometry involving two ina N-donor atoms [Ag—N = 2.181 (6) and 2.185 (5) Å] and a bridging oxalate O-donor atom [Ag—O = 2.620 (4) Å]. The three-dimensional heterometallic Sm—Ag coordination polymer, having a unique (3,4,6)-connected five-nodal net topology, is constructed from two-dimensional samarium–oxalate layers and pillared Ag(ina)2 subunits. Intermolecular water–carboxylate O—H...O hydrogen-bonding interactions are also present.