Crystal structure of disodium trans-disulphitodiamminepalladate(II) hexahydrate

Abstract

The structure of Na₂[Pd(SO₃)₂(NH₃)₂],6H₂O has been determined. It forms crystals of space group P, with a= 8·92 ± 0·02, b= 6·52 ± 0·02, c= 7·07 ± 0·02 Å, α= 73·5 ± 0·2°, β= 102·5 ± 0·2°, γ= 81·6 ± 0·2°; and one formula weight in the unit cell. The structure was solved by Patterson methods and refined by full-matrix least-squares. There is the expected square planar co-ordination around the palladium atom, the sulphite groups being bonded through sulphur, in the trans-configuration and keeping the shape of a trigonal pyramid. Each of the sodium ions is surrounded by six atoms in a distorted octahedral co-ordination. Chains of these octahedra, sharing two edges with two neighbouring octahedra, run parallel to the b axis, the chains being connected in the other two dimensions through the oxygen atoms of the sulphite groups of the [Pd(SO₃)₂(NH₃)₂]^2– ion. Some important distances and angles are: Pd–S, 2·294 ± 0·006; Pd–N, 2·060 ± 0·009; S–O, 1·483 ± 0·005 Å; O–S–O, 108·7 ± 0·2°, S–Pd–N, 90·9 ± 0·3°. These results are compared with the dimensions of [PdSO₃(NH₃)₃] there being a significant lengthening of the Pd–S bond, and no appreciable difference in the dimensions of the sulphite group in the [Pd(SO₃)₂(NH₃)₂]^2– ion.