Keggin结构多金属氧酸盐α-[SiW_(12)O_(40)]^(4-)的从头算理论研究  

Ab initio Studies on Keggin Structure Polyoxometalate α-[SiW_(12)O_(40)]^(4-)

作　　者：郭元茹[1] 潘清江[2] 韦永德[1] 李中华[1] 周百斌[1] 

机构地区：[1]哈尔滨工业大学应用化学系,哈尔滨150001 [2]黑龙江大学化学化工学院,哈尔滨150080

出　　处：《高等学校化学学报》2003年第10期1862-1864,共3页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 96710 0 9)资助

摘　　要：采用从头算 Hartree-Fock方法对具有 Keggin结构的多金属氧酸盐离子 α-[Si W12 O40 ]4-进行优化 .以基态几何为基础 ,进行单激发组态相互作用 ( CIS)计算 .结果表明 ,WO6单元形成扭曲的八面体 ,而 Si O4部分仍具有准四面体结构 ;阴离子的 4个三金属簇 W3 O13 可容纳 3～ 4个负电荷 ,从微观结构上揭示了杂多阴离子拥有大量负电荷仍能稳定的原因 .The polyoxometalate α-[SiW 12O 40] 4- with the Keggin structure was fully optimized by the ab {initio} Hartree-Fock method. The optimized geometry parameters of the title compound agree with experimental values. Based on such calculations, the single excited configuration interaction (CIS) method was performed to calculate the excited states related to absorptions. The absorption maximum was calculated at 232 nm by using the CIS method and assigned as O d→W and O c→W charge transfer transition, comparable to the 260 nm absorption of α-H 4SiW 12O 40 in the experiment. The calculations showed that the distortion of WO 6 unit can stabilize the whole molecule and the SiO 4 unit has the quasi-tetrahedral structure. The four W 3O 13 units in the heteropolyacid can possess 3-4 negative charges, which theoretically reveals why the unit with more electrons in the anion is still stable.

关 键 词：KEGGIN结构 多金属氧酸盐 α-[SiWl2O40]^4- 从头算 X射线晶体衍射 杂多酸 

分 类 号：O641.4[理学—物理化学]