Synthesis,Structure　and　Properties　of　Inverse-Keggin　Potassium　Tetraniobooctatungstosilicate

作     者：YUE Bin, TANG Li-hao, RUI Cheng-guo, LIU Hui-zhang, JIN Song-lin, ZHU Si-san (Department of Chemistry,Fudan University,Shanghai ,200433) LIU Jie and CHEN Min-qin (Center of Analysis and Measurement, Fudan Unive 

作者机构：FUDAN UNIVDEPT CHEMSHANGHAI 200433PEOPLES R CHINA FUDAN UNIVCTR ANAL & MEASUREMENTSHANGHAI 200433PEOPLES R CHINA 

出 版 物：《Chemical Research in Chinese Universities》 (高等学校化学研究（英文版）)

年 卷 期：1997年第13卷第3期

页      面：195-200页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 070301[理学-无机化学] 

主　　题：Tetraniobooctatungstosilicate Synthesis Inverse -Keggin structure 

摘      要：Potassium tetraniobooccatungotosilicate, K8 [SiNb4 W8 O40] · 12H2 O was pre-pared by the reaction of white powdery tungstic acid, potassium niobate and potas -sium silicate in aqueous solution with pH value adjusted by potassium carbonate。The heteropolyniobotungstate crystallized in cubic space group Pm3m with unit cellparameters ;: a = 1.0640(1)nm,Z=1,V=1 .2045(5)nm3,R=0.055,Rw =0.062。The anion has inverse,Keggin structure,in which the central SiO4 tetrahedron isdistributed statistically in two orientations。The twelve outer metal positions arerandomly occupied by four niobium and eight tungsten atoms. Moreover, infraredspectrat electronic :spectra and thermogram were measured。