Synthesis, structure determination and characterization by UV–Vis and IR spectroscopy of bis(diisopropylammonium) cis-dichloridobis(oxalato-κ² O ¹,O ²)stannate(IV)

Abstract

The organic–inorganic title salt, (C6H16N)2[Sn(C2O4)2Cl2] or ( i Pr2NH2)2[Sn(C2O4)2Cl2], was obtained by reacting bis(diisopropylammonium) oxalate with tin(IV) chloride dihydrate in methanol. The SnIV atom is coordinated by two chelating oxalate ligands and two chloride ions in cis positions, giving rise to an [Sn(C2O4)2Cl2]2− anion (point group symmetry 2), with the SnIV atom in a slightly distorted octahedral coordination. The cohesion of the crystal structure is ensured by the formation of N—H...O hydrogen bonding between (iPr2NH2)+ cations and [SnCl2(C2O4)2]2− anions. This gives rise to an infinite chain structure extending parallel to [101]. The main inter-chain interactions are van der Waals forces. The electronic spectrum of the title compound displays only one high intensity band in the UV region assignable to ligand–metal ion charge-transfer (LMCT) transitions. An IR spectrum was also recorded and is discussed.