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在pH=7.5的水溶液中,Na_2WO_4·2H_2O,NaAsO_2,CoCI_2·6H_2O与对氨基吡啶反应,得到了一种新的夹心型杂多钨酸盐Na_6(C_5H_7N_2){[Na(H_2O)_2]_3Co(H_2O)_5[Co(H_2O)]_3(AsW_9O_(33))_2}·27H_2O单晶,用X射线单晶衍射法及元素分析确定了结构,晶体属三斜晶系,p1~-空间群,其晶胞参数为:a=1.3276(8)nm,b=1.7581(10)nm,c=2.4381(14)nm,a= 70.954(9)°,β=86.663(9)°,γ=72.885(9)°,V=5.136(5)nm~3,Z=2,R_1=0.0608,wR_2=0.0848[I>2σ(I)].在{[Na(H_2O)_2]_3Co(H_2O)_5[Co(H_2O)]_3(AsW_9O_(33))2}~(7-)阴离子中,一个Co~(2+)与聚阴离了{[Na(H_2O)_2]_3[Co(H_2O)]_3(AsW_9O_(33))_2}~(9-)的一个端基氧共价连接,Co~(2+)呈现出5和6两种配位数,质子化的氨基吡啶正离子作为抗衡离子存在于晶体之中.对标题化合物进行了IR,UV-Vis,TG-DSC表征.对该化合物、Na_2WO_4·2H_2O及COCl_2·6H_2O催化H_2O_2氧化乙醛的活性进行了比较研究,该化合物的催化活性远优于简单化合物Na_2WO_4·2H_2O和CoCl_2·6H_2O.
A new sandwich type heteropolytungstate salt, Na_6 (C_5H_7N_2) {[Na (H_2O) _2] _3Co (H_2O_4) was obtained by the reaction of Na_2WO_4 · 2H_2O, NaAsO_2 and CoCl_2 · 6H_2O with p- H_2O) _5 [Co (H_2O)] _3 (AsW_9O_ (33)) _2} · 27H_2O single crystal. The structure was confirmed by single crystal X-ray diffraction and elemental analysis. The lattice parameters are a = 1.3276 (8) nm, b = 1.7581 (10) nm, c = 2.4381 (14) nm, a = 70.954 (9) °, β = 86.663 (9) ° and γ = 72.885 (H_2O) _2] _3Co (H_2O) _5 [Co (H_2O) _5 [Co (H_2O) _5] (Co (H 2 O)] 3 (Co (H 2 O) 3) and polyanion in the anion of H_2O_3 (AsW_9O_ (33)) 2} AsW_9O_ (33)) _2} ~ (9-) is covalently linked to one terminal oxygen, Co 2+ exhibits 5 and 6 coordination numbers. The protonated aminopyridine cation exists as a counterion The title compound was characterized by IR, UV-Vis and TG-DSC.The catalytic activities of the compound, Na 2 WO 4 · 2H 2 O and COCl 2 · 6H 2 O catalyzed by H 2 O 2 were compared and the catalytic activity was far better The simple compounds Na_2WO_4 · 2H_2O and CoCl_2 · 6H_2O.