[B-SbW9O33]9-亚基与过渡金属离子（Mn2+、Cu2+、Co2+）在水溶液中的自组装：含低价态Sb(III)杂原子的夹心型多金属氧酸盐的合成、结构及磁性能

Self-assembly of [B-SbW9O33]9- subunit with transition metal ions (Mn2+, Cu2+, Co2+) in aqueous solution: syntheses, structures and magnetic properties of sandwich type polyoxometalates with Subvalent Sb(III) heteroatom.

作者信息

Wang Jing-Ping, Ma Peng-Tao, Li Jie, Niu Hong-Yu, Niu Jing-Yang

机构信息

Institute of Molecular and Crystal Engineering, School of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan, 475004, P.R. China.

出版信息

Chem Asian J. 2008 May 5;3(5):822-33. doi: 10.1002/asia.200700363.

DOI:10.1002/asia.200700363

PMID:18444239

Abstract

Rational self-assembly of Sb(2)O(3) and Na(2)WO(4), or (NH(4))(18)[NaSb(9)W(21)O(86)] with transition-metal ions (Mn(2+), Cu(2+), Co(2+)), in aqueous solution under controlled conditions yield a series of sandwich type complexes, namely, Na(2)H(2)[Mn(2.5)W(1.5)(H(2)O)(8)(B-beta-SbW(9)O(33))(2)]32 H(2)O (1), Na(4)H(7)[Na(3)(H(2)O)(6)Mn(3)(mu-OAc)(2)(B-alpha-SbW(9)O(33))(2)]20 H(2)O (OAc=acetate anion) (2), NaH(8)[Na(2)Cu(4)Cl(B-alpha-SbW(9)O(33))(2)]21 H(2)O (3), Na(8)K[Na(2)K(H(2)O)(2){Co(H(2)O)}(3)(B-alpha-SbW(9)O(33))(2)] 10 H(2)O (4), and Na(5)H[{Co(H(2)O)(2)}(3)W(H(2)O)(2)(B-beta-SbW(9)O(33))(2)]11.5 H(2)O (5). These structures are determined by using the X-ray diffraction technique and further characterized by obtaining IR spectra and performing elemental analysis. Structure analysis reveals that polyoxoanions in 1 and 5 comprise of two B-beta-SbW(9)O(33) building units, whereas 2, 3, and 4 consist of two isomerous B-alpha-SbW(9)O(33) building blocks, which are all linked by different transition-metal ions (Mn(2+), Cu(2+), or Co(2+)) with different quantitative nuclearity. It should be noted that compound 2 represents the first one-dimensional sinusoidal chain based on sandwich like tungstoantimonate building blocks through the carboxylate-bridging ligands. Additionally, 3 is constructed from sandwiched anions Na(2)Cu(4)Cl(B-alpha-SbW(9)O(33))(2) linked to each other to form an infinitely extended 2D network, whereas 5 shows an interesting 3D framework built up from offset sandwich type polyoxoanion {Co(H(2)O)(2)}(3)W(H(2)O)(2)(B-beta-SbW(9)O(33))(2) linked by Co(2+) and Na(+) ions. EPR studies performed at 110 K and room temperature reveal that the metal cations (Mn(2+), Cu(2+), Co(2+)) reside in a square-pyramidal geometry in 2, 3, and 4. The magnetic behavior of 1-4 suggests the presence of weak antiferromagnetic coupling interactions between magnetic metal centers with the exchange integral J=-0.552 cm(-1) in 2.

摘要

在可控条件下，三氧化二锑（Sb₂O₃）与钨酸钠（Na₂WO₄）或（NH₄）₁₈[NaSb₉W₂₁O₈₆]在水溶液中与过渡金属离子（Mn²⁺、Cu²⁺、Co²⁺）进行合理的自组装，生成了一系列夹心型配合物，即Na₂H₂[Mn₂.₅W₁.₅(H₂O)₈(B-β-SbW₉O₃₃)₂]·32H₂O（1）、Na₄H₇[Na₃(H₂O)₆Mn₃(μ-OAc)₂(B-α-SbW₉O₃₃)₂]·20H₂O（OAc = 醋酸根阴离子）（2）、NaH₈[Na₂Cu₄Cl(B-α-SbW₉O₃₃)₂]·21H₂O（3）、Na₈K[Na₂K(H₂O)₂{Co(H₂O)}₃(B-α-SbW₉O₃₃)₂]·10H₂O（4）和Na₅H[{Co(H₂O)₂}₃W(H₂O)₂(B-β-SbW₉O₃₃)₂]·11.5H₂O（5）。这些结构通过X射线衍射技术确定，并通过获得红外光谱和进行元素分析进一步表征。结构分析表明，1和5中的多金属氧酸盐由两个[B-β-SbW₉O₃₃]⁹⁻结构单元组成，而2、3和4由两个异构的[B-α-SbW₉O₃₃]⁹⁻结构单元组成，它们都通过不同定量核数的不同过渡金属离子（Mn²⁺、Cu²⁺或Co²⁺）连接。需要注意的是，化合物2代表了基于夹心状钨锑酸盐结构单元通过羧酸盐桥连配体形成的第一个一维正弦链。此外，3由相互连接形成无限延伸二维网络的夹心阴离子[Na₂Cu₄Cl(B-α-SbW₉O₃₃)₂]⁹⁻构成，而5显示出由通过Co²⁺和Na⁺离子连接的错位夹心型多金属氧酸盐[{Co(H₂O)₂}₃W(H₂O)₂(B-β-SbW₉O₃₃)₂]⁶⁻构建的有趣三维框架。在110K和室温下进行的电子顺磁共振研究表明，金属阳离子（Mn²⁺、Cu²⁺、Co²⁺）在2、3和4中呈四方锥几何构型。1 - 4的磁行为表明磁性金属中心之间存在弱反铁磁耦合相互作用，其中2中的交换积分J = -0.552 cm⁻¹。