Isostructural [Au6Pd6(Pd6-xNix)Ni20(CO)44]6- and [Au6Ni32(CO)44]6- Clusters Containing Corresponding Nonstoichiometric Au6Pd6(Pd6-xNix)Ni20 and Stoichiometric Au6Ni32 Nanosized Cores: Substitutional Pd/Ni Crystal Disorder (Coloring Problem) at Only Six Specific Nonadjacent Pseudoequivalent Metal Sit
Isostructural [Au6Pd6(Pd6-xNix)Ni20(CO)44]6- and [Au6Ni32(CO)44]6- Clusters Containing Corresponding Nonstoichiometric Au6Pd6(Pd6-xNix)Ni20 and Stoichiometric Au6Ni32 Nanosized Cores: Substitutional Pd/Ni Crystal Disorder (Coloring Problem) at Only Six Specific Nonadjacent Pseudoequivalent Metal Sit
复制标题
含有相应非化学计量 Au6Pd6(Pd6-xNix)Ni20 和化学计量 Au6Ni32 纳米核的同结构 [Au6Pd6(Pd6-xNix)Ni20(CO)44]6- 和 [Au6Ni32(CO)44]6- 簇：替代 Pd/Ni 晶体无序 (
DOI：
--
复制
发表时间：
1999
期刊：
影响因子：
--
通讯作者：
L. F. Dahl
中科院分区：
文献类型：
--
作者：
N. Tran;M. Kawano;D. Powell;and Randy K. Hayashi;C. Campana;L. F. Dahl
为了获得大的三金属Au - Pd - Ni羰基团簇，首次报道了高核三金属羰基团簇[Au6Pd6(Pd6-xNix)Ni20(CO)44]6-(1)。其38原子核心的中心对称结构理想地由两个内部的Au3M3Ni6层和两个外部的Pd3层以及两个Pd3和六个auni2覆盖的Ni原子组成。得到的类似八面体的Au6核被两个Pd3三角形反棱镜地盖在相对的三角形面上。通过SMART CCD系统对来自不同样品的7个[PPh4]+盐晶体进行完整的x射线衍射分析，明确了其非化学计量成分的微观性质。在六个特定的非相邻原子M位点（三个晶体学独立）上发现了取代的Pd/Ni晶体紊乱；对于（6−x） Pd/x Ni原子的复合六位点晶体无序，测定了7个晶体的x值范围为2.1 （65% Pd, 35% Ni）至5.5 (8% Pd，…
Efforts to obtain large trimetallic Au−Pd−Ni carbonyl clusters have given rise to the first reported high-nuclearity trimetallic carbonyl cluster [Au6Pd6(Pd6-xNix)Ni20(CO)44]6- (1). The centrosymmetric architecture of its 38-atom core ideally consists of the hcp stacking of two inner Au3M3Ni6 and two outer Pd3 layers along with two Pd3-capped and six AuNi2-capped Ni atoms. The resulting octahedral-like Au6 kernel is antiprismatically capped on opposite triangular faces by the two Pd3 triangles. The microscopic nature of its nonstoichiometric composition was unequivocally established from complete X-ray diffraction analyses via a SMART CCD system of seven crystals of its [PPh4]+ salt from different samples. A substitutional Pd/Ni crystal disorder was found at only six specific nonadjacent atomic M sites (three crystallographically independent); for the composite six-site crystal disorder of the (6 − x) Pd/x Ni atoms, x was determined for the seven crystals to range from 2.1 (65% Pd, 35% Ni) to 5.5 (8% Pd, ...