Structural diversity and properties of M(II) 4-carboxyl phenoxyacetate complexes with 0D-, 1D-, 2D- and 3D M-cpoa framework
Structural diversity and properties of M(II) 4-carboxyl phenoxyacetate complexes with 0D-, 1D-, 2D- and 3D M-cpoa framework
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DOI：
10.1039/b703429f
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发表时间：
2007-07
期刊：
影响因子：
3.1
通讯作者：
Wenjuan Zhuang;Xiang-Jun Zheng;Licun Li;D. Liao;Hui Ma;Lin-pei Jin
中科院分区：
文献类型：
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作者：
Wenjuan Zhuang;Xiang-Jun Zheng;Licun Li;D. Liao;Hui Ma;Lin-pei Jin
本文报道了九种新的不对称H_2cpoa金属配合物[Co（Hcpoa）_2（bpe）_2（H_2O）_2]（1），[Co（cpoa）（bpe）_1.5（H_2O）]·H_2O（2），[Co（Hcpoa）_2（4，4 ′-bpy）2]（3）、[Co（4，4 ′-bpy）（H2O）4]·[Co（cpoa）2（H2O）2]·2H2O（4），[Ni（cpoa）（4，4 ′-bpy）（H2O）2]（5），[Ni（cpoa）（bpe）1.5（H2O）]（6），[Zn2（cpoa）2（bpe）（H2O）]（7），在水热/溶剂热条件下合成了[Zn（cpoa）（bpe）0.5]·0.5（i-C3H7OH）（8）和[Zn（cpoa）（bpe）0.5]·0.5（n-C3H7OH）（9）（H2cpoa = 4-羧基苯氧基乙酸，bpe = 1，2-双（4-吡啶基）乙烷，4，4 ′-bpy = 4，4 ′-联吡啶）。X射线单晶结构分析表明，它们具有从0D（1）、1D（3，4）、2D（5，7，8）到3D（2，6，9）的金属有机骨架结构。CoCl_2/H_2cpoa/bpe（1：1：1）体系在起始pH约为1.5时形成配合物1。8，和复杂的2在12。CoCl2/H2cpoa/4，4 ′-bpy（1：1：1）反应生成具有一维链状结构的配合物3，而摩尔比为1：1：0.5的配合物4则具有两个罕见的同金属配合物离子对的一维金属有机骨架。通过改变加入的有机溶剂，在相同的反应条件下，得到了二维层状骨架的配合物8和微孔三维骨架的配合物9。客体分子n-C3H7OH占据9.热重和粉末X射线衍射分析表明，9的微孔三维框架保持后，去除客体分子。并且可以观察到可逆的脱醇/再醇过程。磁性测量显示在2，4和5中的金属离子之间的反铁磁相互作用，在300 - 18 K的范围内的反铁磁相互作用和在6中低于18 K的Ni（II）离子之间的铁磁相互作用。
Nine new metal complexes with an asymmetric H2cpoa ligand, [Co(Hcpoa)2(bpe)2(H2O)2] (1), [Co(cpoa)(bpe)1.5(H2O)]·H2O (2), [Co(Hcpoa)2(4,4′-bpy)2] (3), [Co(4,4′-bpy)(H2O)4]·[Co(cpoa)2(H2O)2]·2H2O (4), [Ni(cpoa)(4,4′-bpy)(H2O)2] (5), [Ni(cpoa)(bpe)1.5(H2O)]·H2O (6), [Zn2(cpoa)2(bpe)(H2O)] (7), [Zn(cpoa)(bpe)0.5]·0.5(i-C3H7OH) (8) and [Zn(cpoa)(bpe)0.5]·0.5(n-C3H7OH) (9) (H2cpoa = 4-carboxyphenoxy acetic acid, bpe = 1,2-bis(4-pyridyl)ethane, 4,4′-bpy = 4,4′-bipyridine) were synthesized under hydro/solvothermal conditions. X-ray single-crystal structural analyses reveal that they have metal–organic frameworks ranging from 0D (1), 1D (3, 4), 2D (5, 7, 8) to 3D structure (2, 6, 9). The reaction of the CoCl2/H2cpoa/bpe (1 : 1 : 1) system results in the formation of complex 1 at the starting pH of ca. 8, and complex 2 at 12. The reaction of CoCl2/H2cpoa/4,4′-bpy (1 : 1 : 1) forms complex 3 with a 1D chain structure, while a molar ratio of 1 : 1 : 0.5 leads to the formation of complex 4 with two 1D metal–organic frameworks of rarely reported homometal complex ion pairs. By changing the added organic solvent, the 2D layer framework of complex 8 and the microporous 3D framework of complex 9 were obtained under the same reaction conditions. The guest n-C3H7OH molecules occupy 1D channels in 9. Thermogravimetric and powder X-ray diffraction analyses show that the microporous 3D framework of 9 is maintained after the removal of the guest molecule. And a reversible dealcoholization/realcoholization process can be observed. The magnetic measurements show antiferromagnetic interactions between the metal ions in 2, 4 and 5, and antiferromagnetic interaction in the range of 300–18 K and ferromagnetic interaction between Ni(II) ions below 18 K in 6.