Kaba Mahmoud S., Song In K., Duncan Dean C., Hill Craig L., Barteau Mark A.
Center for Catalytic Science and Technology, Department of Chemical Engineering, University of Delaware, Newark, Delaware 19716, and Department of Chemistry, Emory University, Atlanta, Georgia 30322.
Inorg Chem. 1998 Feb 9;37(3):398-406. doi: 10.1021/ic9705655.
Reported here are both STM images and spatially resolved tunneling spectra of four different polyoxometalate (POM) structural class members: Keggin structure, H(3)[PW(12)O(40)] (spherical); Finke-Droege (FD) structure, Na(16)[Cu(4)(H(2)O)(2)(P(2)W(15)O(56))(2)] (prolate spheroidal); Wells-Dawson (WD) structure, H(7)[P(2)Mo(17)VO(62)] (prolate spheroidal); and Pope-Jeannin-Preyssler (PJP) structure, K(12.5)Na(1.5)[NaP(5)W(30)O(110)] and (NH(4))(14) [NaP(5)W(30)O(110)] (oblate spheroidal). In all four cases, the results demonstrate the formation of well-ordered 2-D inorganic POM anion arrays (composed of catalytically active molecular constituents) on graphite. Importantly, the image shapes and lattice spacings accurately reflect the POM anisotropies, permitting the determination of anion orientation with respect to the surface plane.
本文报道了四种不同结构类型的多金属氧酸盐（POM）的扫描隧道显微镜（STM）图像和空间分辨隧道谱：凯吉结构的H(3)[PW(12)O(40)]（球形）；芬克 - 德罗格（FD）结构的Na(16)[Cu(4)(H(2)O)(2)(P(2)W(15)O(56))(2)]（长椭球形）；韦尔斯 - 道森（WD）结构的H(7)[P(2)Mo(17)VO(62)]（长椭球形）；以及波普 - 让南 - 普雷斯勒（PJP）结构的K(12.5)Na(1.5)[NaP(5)W(30)O(110)]和(NH(4))(14) [NaP(5)W(30)O(110)]（扁椭球形）。在所有这四种情况下，结果表明在石墨上形成了有序的二维无机POM阴离子阵列（由催化活性分子成分组成）。重要的是，图像形状和晶格间距准确反映了POM的各向异性，从而能够确定阴离子相对于表面平面的取向。
