Redetermination of the crystal structure of dimethylbis[2,4-pentanedionato(1-)-kappa O-2(2),O-4]tin(IV)

Abstract

The redetermination of the title compound, [Sn(CH3)(2)(C5H7O2)(2)] or SnMe2(acac)(2), from CCD data recorded at 100 K basically confirms the previous study based on integrated film data recorded at room temperature [Miller & Schlemper (1972). Inorg. Chem. 12, 677-681], but reveals a remarkable shrinkage of the a axis [7.12 (1) > 6.7694 (4) angstrom]. The molecule belongs to point group C-i with the Sn-IV atom on a centre of inversion. The Sn-IV atom shows a slightly distorted octahedral coordination sphere with the methyl groups in trans positions and a Sn-C bond length of 2.115 (2) angstrom which may serve as a standard value for an Sn-CH3 bond of an octahedrally coordinated Sn-IV atom. The Sn-O bonds involving the two carbonyl groups of the acetylacetonate ligand are of equal length [2.180 (1) and 2.183 (1) angstrom], as are the C O [1.273 (1) and 1.274 (1) angstrom] and C-C bond lengths [1.393 (2) and 1.400 (2) angstrom]. The acetylacetonate ligand deviates considerably from planarity, with a dihedral angle of 5.57 (9)degrees between the least-squares planes of the two acetone moieties. The four O atoms of the two symmetry-related acetylacetonate ligands are arranged in a nearly quadratic rectangle. Weak C-H center dot center dot center dot O interactions consolidate the crystal packing.