新型杂多阴离子[{Na_2(H_2O)_3}Ni(H_2O)VOAs_4W_(40)O_(140)]^(21-)的结构及表征  

Structure and Characterization of a Novel Heteropolyoxoanion [{Na_2(H_2O)_3}Ni(H_2O)VOAs_4W_(40)O_(140)]^(21-)

作　　者：刘斌[1] 薛岗林[1] 胡怀明[1] 王兰英[1] 史启祯[1] 郑丽敏[2] 忻新泉[2] 王继武[3] 

机构地区：[1]西北大学化学系 [2]南京大学国家配位化学重点实验室,南京210093 [3]延安大学化学化工学院

出　　处：《化学学报》2004年第13期1222-1225,J002,共5页Acta Chimica Sinica

基　　金：高等学校重点实验室访问学者基金;陕西省自然科学基金 (No .2 0 0 3B0 1 )资助项目

摘　　要：在pH =4.5的水溶液中 ,Na2 7[NaAs4W40 O14 0 ]·60H2 O与NiCl2 ·6H2 O ,NaVO3 ·4H2 O和NH4Cl反应得到了不同过渡金属离子占据S2位的新型杂多钨酸盐 (NH4) 2 1[{Na2 (H2 O) 3 }Ni(H2 O)VOAs4W40 O14 0 ]·5 3H2 O ,用X射线单晶衍射法和元素分析确定了其结构 .晶胞参数为 :a =2 .3 3 0 5 ( 14 )nm ,b =2 .9467( 19)nm ,c =1.2 671( 16)nm ,V =8.70 1( 9)nm3 ,Z =2 ,空间群Pmmn .在杂多阴离子 [{Na2 (H2 O) 3 }Ni(H2 O)VOAs4W40 O14 0 ] 2 1-中 ,配体 {As4W40 }的 1个中心位和 4个S2位可以选择性地被不同的金属离子所占据 ,其中相对的 2个S2位被Ni2 + 和V5+ 统计性地占据 ,每种离子占据的概率为 5 0 % ;{As4W40 }中的另 2个S2位分别被2个Na+ 占据 ,2个Na+ 间通过一配位水分子桥连 .讨论了标题化合物的IR 。A novel large polyoxometalate (NH4)(21)[{Na-2(H2O)(3)}Ni(H2O)VOAs4W40O140] . 53H(2)O was synthesized by the reaction of Na-27[ NaAs4W40O140] . 60H(2)O with NiCl2 . 6H(2)O, NaVO3 . 4H(2)O and NH4Cl in pH = 4. 5 aqueous solution. Its structure was determined by single crystal X-ray diffraction. Crystal data for the titled compound are: orthogonal system, Pmmn space group, a = 2.3305(14) nm, b = 2.9467(19) nm, c = 1.2671(16) nm, V = 8.701 (9) nm(3), Z = 2, D-c = 4. 378 g/cm(3), p = 27.372 mm(-1), R-1 = 0.0596, wR(2) = 0.1056 [I > 2sigma(I)]. The opposite two of four S2 sites of the big cyclic ligand [As4W40O140](28-) are disorderly occupied by one V5+ and one Ni2+ with the probability that each transition metal ion occupies the same S2 site being 50%, and the other two S2 sites are occupied by two Na+ which are bridged by a water molecule. IR spectra, TG and magnetic properties of the compound were also discussed.

关 键 词：晶体结构 磁学性质 杂多钨酸盐 镍配合物 过渡金属离子 

分 类 号：O641.4[理学—物理化学]