catena-Poly[[di-tert-butyl-tin(IV)]-μ-oxalato].

The title compound, [Sn(C4H9)2(C2O4)] n , an unexpected side product in the reaction of di-tert-butyl-tin(IV) oxide with nitric acid, represents the first diorganotin(IV) oxalate to be structurally characterized. The Sn(IV) atom of the one-dimensional coordination polymer is located on a mirror plane and is coordinated by two chelating oxalate ions with two rather different Sn-O bond lengths of 2.150 (1) and 2.425 (1) Å, and two t-butyl groups with Sn-C bond lengths of 2.186 (2) and 2.190 (2) Å. The coordination polyhedron around the Sn(IV) atom is a distorted tetra-gonal disphenoid. The centrosymmetric oxalate ion also has an asymmetric coordination geometry, as reflected by the two slightly different C-O bond lengths of 1.242 (2) and 1.269 (2) Å. The chains of the polymer propagate along the b-axis direction. Only van der Waals inter-actions are observed between the chains.