Lee Pei-Shan, Igashira-Kamiyama Asako, Kuwamura Naoto, Yoshinari Nobuto, Konno Takumi
Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan).
Chemistry. 2014 May 26;20(22):6646-9. doi: 10.1002/chem.201402777. Epub 2014 Apr 24.
Herein, a unique coordination system that exhibits multiple chiral inversions and molecular dimerization in response to a subtle pH change is reported. Treatment of (Δ)2-H3[Au3Co2(L-cys)6] (H3[1 a]) with Co3(aet)63 (aet=2-aminoethanethiolate) in water at pH 7 gave a 1:1 complex salt of Co3(aet)6 and 1 a, retaining the Au(I)3Co(III)2 structure and chiral configurations of 1 a. Similar treatment at pH 9 led to not only the inversion of all of the chiral Co(III) and S centers but also the dimerization of 1 a, giving a 2:1 complex salt of Co3(aet)6 and (Λ)4(R)12-Au6Co4(L-cys)12 (2). When dissociated from Co3(aet)6 in solution, 2 was converted to (Λ)2(R)6-Au3Co2(L-cys)6 (1 b) with retention of the chiral configurations.
本文报道了一种独特的配位体系，该体系在微妙的pH变化下会出现多个手性反转和分子二聚化现象。在pH = 7的水中，用Co3(aet)63（aet = 2-氨基乙硫醇盐）处理(Δ)2-H3[Au3Co2(L-cys)6]（H3[1 a]），得到了Co3(aet)6和1 a的1:1络合盐，保留了1 a的Au(I)3Co(III)2结构和手性构型。在pH = 9时进行类似处理，不仅导致所有手性Co(III)和S中心的反转，还导致1 a的二聚化，得到了Co3(aet)6和(Λ)4(R)12-Au6Co4(L-cys)12（2）的2:1络合盐。当在溶液中与Co3(aet)6解离时，2转化为(Λ)2(R)6-Au3Co2(L-cys)6（1 b），手性构型得以保留。
