Department of Materials Science, Faculty of Science, Kanagawa University, Hiratsuka, Kanagawa 259-1293, Japan.
Inorg Chem. 2010 Sep 20;49(18):8247-54. doi: 10.1021/ic100530h.
The preparation and structural characterization of a novel intercluster compound, {Au(PPh(3))}(4)(μ(4)-O)α-PW(12)O(40)·4EtOH (1), constructed between a tetrakis{triphenylphosphinegold(I)}oxonium cation and a saturated α-Keggin polyoxometalate (POM) are described. The tetragold(I) cluster oxonium cation was formed during the course of carboxylate elimination of a monomeric phosphinegold(I) carboxylate complex, i.e., [Au((R,S)-pyrrld)(PPh(3))] [(R,S)-Hpyrrld = (R,S)-2-pyrrolidone-5-carboxylic acid], in the presence of the free acid form of a Keggin POM, H(3)[α-PW(12)O(40)]·7H(2)O. The liquid-liquid diffusion between the upper water/EtOH phase containing the Keggin POM and the lower CH(2)Cl(2) phase containing the monomeric gold(I) complex gave a pure crystalline sample of 1 in good yield (42.1%, 0.242 g scale). Complex 1 was formed by ionic interaction between the tetragold(I) cluster cation and the Keggin POM anion. As a matter of fact, the POM anion in 1 can be exchanged with the BF(4)(-) anion using an anion-exchange resin (Amberlyst A-27) in BF(4)(-) form. By using other Keggin POMs, such as H(4)[α-SiW(12)O(40)]·10H(2)O and H(3)[α-PMo(12)O(40)]·14H(2)O, the same tetragold(I) cluster cation was also formed, i.e., in the forms of {Au(PPh(3))}(4)(μ(4)-O)[α-SiW(12)O(40)]·2H(2)O (2) and {Au(PPh(3))}(4)(μ(4)-O)α-PMo(12)O(40)·3EtOH (3). Compounds 1-3, as dimethyl sulfoxide-soluble, EtOH- and Et(2)O-insoluble dark-yellowish white solids, were characterized by complete elemental analysis, thermogravimetric and differential thermal analyses, Fourier transform IR, X-ray crystallography, and solid-state (CPMAS (31)P and (29)Si) and solution ((31)P{(1)H} and (1)H) NMR spectroscopy. The molecular structures of 1 and 2 were successfully determined. The tetragold(I) cluster cation was composed of four PPh(3)Au(I) units bridged by a central μ(4)-oxygen atom in the geometry of a trigonal pyramid or distorted tetrahedron.
一种新型的簇间化合物{Au(PPh(3))}(4)(μ(4)-O)α-PW(12)O(40)·4EtOH(1)的制备和结构表征，是由四[三苯基膦金（I）]氧正离子与饱和α-Keggin 多金属氧酸盐（POM）之间形成的。在单体膦金（I）羧酸盐配合物[Au((R，S)-pyrrld)(PPh(3))]的[（R，S）-Hpyrrld=（R，S）-2-吡咯烷酮-5-羧酸]的羧酸根消除过程中，形成了四金（I）簇氧正离子，同时存在 Keggin POM 的游离酸形式 H(3)[α-PW(12)O(40)]·7H(2)O。在含有 Keggin POM 的上相水/乙醇和含有单体金（I）配合物的下相 CH(2)Cl(2)之间进行液-液扩散，得到了产率为 42.1%（0.242g 规模）的纯结晶 1。复合物 1是通过四金（I）簇阳离子和 Keggin POM 阴离子之间的离子相互作用形成的。事实上，1 中的 POM 阴离子可以通过使用阴离子交换树脂（Amberlyst A-27）在 BF(4)(-)形式下与 BF(4)(-)阴离子进行交换。使用其他 Keggin POM，如 H(4)[α-SiW(12)O(40)]·10H(2)O 和 H(3)[α-PMo(12)O(40)]·14H(2)O，也形成了相同的四金（I）簇阳离子，即{Au(PPh(3))}(4)(μ(4)-O)[α-SiW(12)O(40)]·2H(2)O(2)和{Au(PPh(3))}(4)(μ(4)-O)α-PMo(12)O(40)·3EtOH(3)。化合物 1-3 为二甲基亚砜可溶、乙醇和乙醚不溶的深黄色白色固体，通过元素分析、热重和差示热分析、傅里叶变换红外光谱、X 射线晶体学以及固态（(31)P 和 (29)Si CPMAS）和溶液（(31)P{(1)H}和 (1)H）NMR 光谱进行了表征。成功确定了 1 和 2 的分子结构。四金（I）簇阳离子由四个 PPh(3)Au(I)单元通过中心μ(4)-氧原子桥接而成，其几何形状为三角锥形或变形四面体。
