Na_9[Na_3{Co(H_2O)}_3(AsW_9O_(33))_2]·44H_2O的晶体结构及表征

在 p H≈ 6 .5及稀土盐的存在下 ,用 Na2 WO4 · 2 H2 O与 Na As O2 及 Co(NO3 ) 2 · 6 H2 O反应 ,得到了夹层型杂多钨酸盐 Na9Na3 { Co(H2 O) } 3 (As W9O3 3 ) 2 ]· 44H2 O单晶 ,用 X射线单晶衍射法及元素分析确定了其结构 ,晶胞参数为 :a=1 .40 83 (6 ) nm,b=2 .3 2 4 1 (6 ) nm,c=3 .2 1 97(1 0 ) nm,α=90°,β=98.995 (6 )°,γ=90°,V=1 0 .40 8(6 ) nm3 ,Z=4,空间群 C2 /c,R1 =0 .0 6 0 4 ,w R2 =0 .0 792 (I>2 σ) .Na3 { Co(H2 O) } 3 (As W9O3 3 ) 2 ]9-具有近似 D3 h对称性 ,Co2 +的配位数均为 5 .对题示化合物进行了 IR,UV- Vis表征 ,讨论了其形成条件

Synthesis and Crystal Structure of Heteropolytungstate Na9[Na3{Co(H2O)}3(AsW9O33)2]·44H2O

The novel sandwich heteropolytungstate Na 9Na 3{Co(H 2O)} 3(AsW 9O 33) 2]·44H 2O is obtained by the reaction of Na 2WO 4·2H 2O with NaAsO 2 and Co(NO 3) 2·6H 2O under pH≈6.5 and in the existence of rare-earth salt. Its structure is determined by X-ray diffraction analysis and element analysis. The cell parameters are as follows:a=1.408 3(6)nm,b=2.3241(6)nm,c=3.219 7(10)nm,α=90°,β=98 995(6)°,γ=90°,V=10.408(6)nm 3,Z=4;space group:C 2/c,R1=0.060 4,wR2=0.079 2(I>2σ).X-ray diffraction analysis determined all non-hydrogen atomic coordinates. The structure of Na 3{Co(H 2O)} 3(AsW 9O 33) 2] 9- reveals a sandwich-like arrangement of two {α-β-AsW 9}moieties enclosing three Na + and three Co(H 2O) 2+Na 3{Co(H 2O)} 3(AsW 9O 33] 2 9-has an approximate D 3h symmetry. The coordination numbers of all CO 2+ ions in the sandwich anion are five.