Polyoxometalates with supporting phosphate ligand: synthesis and characterization of α-[SiW11O39M(H2PO4)]n−
Polyoxometalates with supporting phosphate ligand: synthesis and characterization of α-[SiW11O39M(H2PO4)]n−
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DOI：
10.1039/b307947n
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发表时间：
2003-10
影响因子：
4
通讯作者：
Jun Peng;Huiyuan Ma;Zhan-gang Han;Bao-xia Dong;Wenzhu Li;Jun Lu;E. Wang
中科院分区：
文献类型：
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作者：
Jun Peng;Huiyuan Ma;Zhan-gang Han;Bao-xia Dong;Wenzhu Li;Jun Lu;E. Wang
合成了一系列具有共价键连接的载体 - 配体的新型Keggin型化合物，其化学式为α - [SiW₁₁O₃₉M(H₂PO₄)]ⁿ⁻（M = Co²⁺、Mn²⁺、Ni²⁺或Cr³⁺），并通过元素分析、红外光谱、循环伏安法、核磁共振以及X射线粉末衍射测量对其进行了表征。其结构让人联想到中国古代的三足酒器，并且是多金属氧酸盐 - 核苷酸相互作用的一种可能模型。一个有趣的性质是，与相应的3d金属单取代Keggin型多金属氧酸盐相比，该系列化合物具有不同的热行为。这在很大程度上可归因于悬垂的表面配体和氢键相互作用。与α - PW₁₁M相比，对于α - PW₁₁M和α - SiW₁₁M - PO₄这两个系列的配合物，³¹P NMR信号的谱线增宽顺序相同，但对于后者，接触相互作用和偶极相互作用可能对磷的化学位移有显著影响。
A novel series of Keggin species with a covalently bonding support-ligand, formulated α-[SiW11O39M(H2PO4)]n− (M = CoII, MnII, NiII or CrIII), have been synthesized and characterized by elemental analyses, IR, CV, NMR and X-ray powder diffraction measurements. The structure is reminiscent of an ancient Chinese three-legged wine vessel, and is a possible model for POM–nucleotide interaction. An interesting property is the different thermal behaviors for this series in comparison with those for corresponding 3d metal monosubstituted Keggin polyoxometalates. This can be attributed largely to the pendant surface ligand and H bonding interaction. Compared with α-PW11M, the orders of line broadening of 31P NMR signals are the same for the two series of complexes α-PW11M and α-SiW11M–PO4, but both contact and dipolar interactions might make a significant contribution to the chemical shift for phosphorus for the latter.