Treatment of a cyclic tripalladium(II) complex, [Pd3(d-pen)3] (d-H2pen: d-penicillamine), with l-methionine (l-Hmet) gave a novel open-chain-type S-bridged heptapalladium(II) complex, [Pd7(d-pen)8(l-met)2]4−, besides a monopalladium(II) complex, [Pd(d-pen)(l-met)]−. A similar reaction using S-methyl-l-cysteine (l-Hsmc) instead of l-Hmet produced an analogous heptapalladium(II) complex, [Pd7(d-pen)8(l-smc)2]4−.

No abstract

The reactions of an S-bridged trinuclear palladium(II) complex, [Pd(3)(D-pen-N,O,S)(3)] (D-H(2)pen = D-penicillamine), with ethylenediamine (en) and racemic (R,R/S,S) 1,2-cyclohexanediamine (chxn) in water gave mononuclear palladium(II) complexes, [Pd(D-pen-N,S)(en)] (1) and [Pd(D-pen-N,S)(chxn)] (2), respectively. Of two diastereomers, [Pd(D-pen-N,S)(R,R-chxn)] (2(R)) and [Pd(D-pen-N,S)(S,S-chxn)] (2(S)), possible for 2, 2(S) was exclusively isolated in a high yield.

The asymmetric unit of the title compound, [Pd4(C5H9NO2S)4]·9.75H2O, contains two neutral tetranuclear complex molecules with similar conformations and 19.5 solvent water mol­ecules. Of the 21 independent water molecules, three exhibit an occupancy of one-half. In each tetranuclear complex molecule, the four PdII atoms have a square-planar coordination environment and are spanned by four d-penicillaminate ligands in a κ4 N,S:S,O coordination mode, forming an eight-membered Pd4S4 metallacycle. In the crystal, two tetra­nuclear mol­ecules are connected to each other through eight N—H⋯O hydrogen bonds between amine and carboxyl­ate groups, constructing a cylindrical dimer. The dimers are further hydrogen-bonded with the solvent water mol­ecules, completing a three-dimensional network.