Coordination Behavior of a D-Penicillaminato Aurate(I) Metalloligand toward Coblat(III) Centers

Treatment of (NH4))[Au(D-Hpen-S)(2)] (D-H(2)pen = D-penicillamine)with CoCl2 center dot 6H(2)O in an acetate buffer solution, followed by air oxidation, gave neutral (Au3Co3III)-Co-I and anionic (Au3Co2III)-Co-I polynuclear complexes, [Au3Co3(D-pen-N,O,S)(6)] ([1]) and [Au3Co2(D-pen-N,S)(6)](3-) ([2](3-)), which were separated by anion-exchange column chromatography. Complexes [1] and [2](3-) each formed a single isomer, and their structures were determined by single-crystal X-ray crystallography. In [1], each of three [Au(D-pen-S)(2)](3-) metalloligands coordinates to two Co-III ions in a bis-tridentate-N,O,S mode to form a cyclic (Au3Co3III)-Co-I hexanuclear structure, in which three [Co(D-pen-N,O,S)(2)](-) octahedral units and six bridging S atoms adopt trans(O) geometrical and R chiral configurations, respectively. In [2](3-), each of three [Au(D-pen-S)(2)](3-) metalloligands coordinates to two Co-III ions in a bis-bidentate-N,S mode to form a (Au3Co2III)-Co-I pentanuclear structure, in which two [Co(D-pen-N,S)(3)](3-) units and six bridging S atoms adopt A and R chiral configurations, respectively.