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

• Published in: Journal of the Chinese Chemical Society (Taipei) 2009-02, Vol.56 (1), p.26-33
• Main Authors: Konno, Takumi, Toyota, Atsushi, Igashira-Kamiyama, Asako
• Format: Article
• Language: English
• Subjects: Chiral metalloaggregates; Polynuclear complex; S-donating metalloligand
• ISSN: 0009-4536; 2192-6549
• DOI: 10.1002/jccs.200900004

Treatment of (NH4)[Au(D‐Hpen‐S)2](D‐H2pen = D‐penicillamine) with CoCl2·6H2O in an acetate buffer solution, followed by air oxidation, gave neutral AuICoIII and anionic AuI3CoIII2 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 CoIII ions in a bis‐tridentate‐N,O,S mode to form a cyclic AuI3CoIII3 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 CoIII ions in a bis‐bidentate‐N,S mode to form a AuI3CoIII2 pentanuclear structure, in which two [Co(D‐pen‐N,S)3]3− units and six bridging S atoms adopt ∧ and R chiral configurations, respectively. Two kinds of S‐bridged AuICoIII polynuclear complexes, [Au3Co3(D‐pen‐N,O,S)6] ([1]) and [Au3Co2(D‐pen‐N,S)6]3‐ ([2]3‐), were produced by treatment of [Au(D‐pen‐S)2]3‐ (D‐H2pen = D‐penicillamine) with Co2+ in an aqueous solution, followed by air oxidation. In [1] and [2]3‐, each [Au(D‐pen‐S)2]3‐ unit coordinates to two CoIII ions in bis‐tridentate‐N,O,S and bis‐bidentate‐N,S modes to form the homochiral [trans(O)]3(R)6 and (?)2(R)6 isomers, respectively.