H_(3+n)[AsMo_(12-n)V_nO_(40)]·9H_2O(n=2—4)的结构  

Structures of H_(3+n)[AsMo_(12)-nV_nO_(40)]·9H_2O(n=2-4)

作　　者：邓谦[1] 张亚梅[1] 黄幼青 胡盛志[2] 

机构地区：[1]暨南大学化学系,广州510632 [2]厦门大学化学系,厦门361005

出　　处：《Chinese Journal of Structural Chemistry》1993年第6期430-436,共7页结构化学（英文）

摘　　要：X光晶体结构分析证实H_(3+n)[AsMo_(12-n)V_+nO_(40)]·9H_2)(n=2—4)的晶体同构,空间群为P,Z=2。n=2时,a=13.951(5),b=14.137(5),c=13.556(4),α=112.44(2),β=109.49(3),γ=60.77(3)°,V=2120.2,M_r=1943.36,D_c=3.044g.cm^(-3),μ=40.90cm^(-1),F(000)=1828。用6216个I>3σ(I)的独立衍射精修结构,R=0.082;n=3时,a=13.891(7),b=14.076(5),c=13.483(5)A,α=112.34(3),α=109.26(3),γ=60.82(3)°,V=2094.5,M_r=1899.37,D_c=3.011g.cm^(-3),μ=40.63cm^(-1),F(000)=1792。用6699个I>3σ(I)的独立衍射精修结构,R=0.054;n=4时,a=13.854(3),b=14.099(2),c=13.501(4),α=112.09(2),β=109.13(2),γ=61.03(2)°,V=2103.0,M_r=1855.38,D_c=2.92(悬浮法),D_c=2.930g.cm^(-3),μ=39.71cm^(-1),F(000)=1756。用7613个I>3σ(I)的独立衍射精修结构,R=0.044。实验采用MoKα辐射,λ=0.71073,T=296K。杂多阴离子均呈准Keggin结构,12个金属原子呈无序分布,可以M(Mo/V)表示。AsO_4四面体中As—O键长1.66—1.68,O—As—O键角均在109.5°左右。畸变的MO_6八面体中,M—O键长分布在1.63—2.36范围。水分子无序处在晶胞中十四个位置上,除O_w(12)和O_w(13)外的水分子均与杂多阴离子形成氢键,且水分子间形成如沸石中那样的复杂?Crystals of H3+n[AsMo12-nVnO40] 9H2O(n=2-4)were shown by X-ray diffraction analysis to be isomorphous,space group P1,Z=2.(I),n=2,a=13.951(5),b=14.137(5),c=13.556(4)A,α=112.44(2),β=109.49(3),γ=60.77(3)° V=2120.2A3,Mr=1943.36,A=3.044g cm-3,μ=40.90cm-1,F(000)=1828,final R=0.082 for 6216 unique observed [I>3o(Ⅰ)]eflections.(Ⅱ)n=3,a=13.891(7),b=14.076(5),c=13.483(5)A,α=112.34(3),β=109.26(3),γ=60.82(3)°,V=2094.5 A3,Mr=1899.37,A=3.011g cm-3,μ=40.63cm-1,F(000)=1792,final R=0.054 for 6699 unique observed [Ⅰ>3o(Ⅰ)]re-flections.(Ⅲ)n=4,a=13.854(3),b=14.099(2),c=13.501(4)A α=112.09(2),β=109.13(2),γ=61.03(2)°,V=2103.0 A3,Mr=1855.38,Dc=2.930,Dc=2.92g cm-3(by floatation),μ=39.71cm-1,F(000)=1756,final R=0.044 for 7613 unique reflections with I>3σ(Ⅰ).The radiation used for compunds(Ⅰ)to(Ⅲ)was MoKa(λ=0.71073A).Tetrahedron of the three Keggin anions is ordered with As-O distances of 1.66-1.68 A and O-As-O angles of around 109.5°.The M-O distances of the distorted Mo6 octahedra range from 1.63 to 2.36A The CAsMo12-nVnO40] 9H2O(n=2-4)heteropolyanions have the same structure but with significant dimensional differences with that of [PMo12-nVnO40]3-Fourteen positions for the zeolite-like bound water molecules could be confirmed,and all the waters except Ow(12)and Ow(13)connect the heteropolyanions into a three-dimensional framwork.Structural comparison between the title compounds and H3CPMo12O40](13-14)H2O is described,and the con-figurational features of 12-heteropolyanions with Mo/V random distribution are also discussed in detail.

关 键 词：晶体结构 砷钼钒杂多酸 结构化学 

分 类 号：O743.53[理学—晶体学]