Redetermination of (d-penicillaminato)lead(II)

In the title coordination polymer, [Pb(C(5)H(9)NO(2)S)](n) {systematic name: catena-poly[(μ-2-amino-3-methyl-3-sulfido­butano­ato)lead(II)]}, the d-penicillaminate ligand coordin­ates to the metal ion in an N,S,O-tridentate mode. The S atom acts as a bridge to two neighbouring Pb(II) ions, thereby forming a double thiol­ate chain. Moreover, the coordinating carboxyl­ate O atom forms bridges to the Pb(II) ions in the adjacent chain. The overall coordination sphere of the Pb(II) ion can be described as a highly distorted penta­gonal bipyramid with a void in the equatorial plane between the long Pb—S bonds probably occupied by the stereochemically active inert electron pair. The amino H atoms form N—H⋯S and N—H⋯O hydrogen bonds, resulting in a cluster of four complex units, giving rise to an R (4) (4)(16) ring lying in the ab plane. The crystal structure of the title compound has been reported previously [Freeman et al. (1974 ▶). Chem. Soc. Chem. Commun. pp. 366–367] but the atomic coordinates have not been deposited in the Cambridge Structural Database (refcode DPENPB). Additional details of the hydrogen bonding are presented here.