A Novel Optical Complex between an Organic Substrate and a Polyoxometalate. Crystal and Molecular Structure of α-H4SiW12O40·4HMPA·2H2O (HMPA = Hexamethylphosphoramide)
A Novel Optical Complex between an Organic Substrate and a Polyoxometalate. Crystal and Molecular Structure of α-H4SiW12O40·4HMPA·2H2O (HMPA = Hexamethylphosphoramide)
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DOI：
10.1021/ic951458i
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发表时间：
1996-07
影响因子：
4.6
通讯作者：
J. Niu;and Xiao-zeng You;C. Duan;Hoong-kun Fun and;Zhongyong Zhou
中科院分区：
文献类型：
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作者：
J. Niu;and Xiao-zeng You;C. Duan;Hoong-kun Fun and;Zhongyong Zhou
合成了α-H_4SiW_（12）O_（40）·4 HMPA·2H_2O（HMPA = H_4SiW_（12）O_（40）·4 HMPA·2H_2O）配合物，并对其进行了表征。溶解在CD 3CN中的标题化合物的电子光谱（λ = 220−500 nm）以及1H NMR光谱证实，该络合物在溶液中解离成游离的SiW 12 O 4 O 4-和HMPA部分，除非有机底物HMPA以非常高的浓度存在。固体反射电子光谱和红外光谱表明，α-H_4SiW_（12）O_（40）与有机基质之间存在相互作用。该配合物在太阳光照射下不具有光敏性，但在近紫外光照射下，HMPA发生氧化，聚氧乙烯酸盐发生还原，导致电荷转移。标题化合物在乙腈水溶液中结晶为淡黄色多面体，分子式为α-H4 SiW 12 O 40·4 HMPA·2 H2 O，属单斜晶系，空间群P21。单位CE…
A solvated complex of α-H4SiW12O40·4HMPA·2H2O composed the heteropolytungstate α-H4SiW12O40 and the organic substrate hexamethylphosphoramide (HMPA) has been synthesised, purified, and characterized. The electronic spectra (λ = 220−500 nm) as well as the 1H NMR spectra for the title compound dissolved in CD3CN establish that this complex dissociates into free SiW12O404- and HMPA moieties in solution unless the organic substrate HMPA is present in very high concentrations. The solid reflectance electronic spectra and IR spectra indicate that there is interaction between the α-H4SiW12O40 and the organic substrate. The complex has no photosensitivity under irradiation of sunlight, but under the near-UV light result in a charge transfer by oxidation of the HMPA and the reduction of the polyoxometalate. Light yellow polyhedrons of the title compound crystallize from the aqueous solvent of acetonitrile and aqueous solution as the formula of α-H4SiW12O40·4HMPA·2H2O in the monoclinic, space group P21. The unit ce...