Hierarchical assembly of extended coordination networks constructed by novel metallacalix[4]arenes building blocks.
Hierarchical assembly of extended coordination networks constructed by novel metallacalix[4]arenes building blocks.
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DOI：
10.1021/ic901113p
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发表时间：
2010-02
影响因子：
4.6
通讯作者：
Xia Li;Benlai Wu;Ruiying Wang;Hong‐yun Zhang;Caoyuan Niu;Yunyin Niu;H. Hou
中科院分区：
文献类型：
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作者：
Xia Li;Benlai Wu;Ruiying Wang;Hong‐yun Zhang;Caoyuan Niu;Yunyin Niu;H. Hou
五个有趣的金属有机纳米结构和网络，[Ni（4）（HL）（4）（bpy）（py）（H（2）O）（5）]（2）x 0.5 H（2）O（1），[Co（4）（HL）（4）（bpy）（py）（H（2）O）（5）]（2）x 0.5 H（2）O（2），[Ni（4）（HL）（4）（H（2）O）（7）]（n）x nH（2）O（3），水热法合成了[Ni（4）（HL）（4）（bpy）（2）（H（2）O）（4）]（n）（4）和[Cd（4）（HL）（4）（H（2）O）]（n）（5）[H（3）L = 2-（吡啶-2-基）-1H-咪唑-4，5-二甲酸，py =吡啶，bpy = 4，4 '-联吡啶].有趣的是，所有化合物都由新型金属杯[4]芳烃结构单元M（4）（HL）（4）组成，其中双去质子化的HL以相同的双螯合方式mu-kN，N“：kO，N”显示出通过4，5-咪唑二羧酸酯和2-吡啶基的合作的强配位取向。非常有趣的是，M（4）（HL）（4）的对称性以及M（4）（HL）（4）中金属节点和HL之间的连接方式对反应条件敏感，并且所产生的结构基序随次级配体和金属节点而变化。在1和2中，两个C（1）对称的M（4）（HL）（4）单元被bpy桥连成具有两个不同空腔的二聚体手性纳米分子。当用NaOH去质子化时，Ni（II）和HL的组合形成假S（4）-或S（4）-对称的M（4）（HL）（4），其进一步组装成bpy桥接的5重互穿类金刚石结构的1D手性晶体3或罕见的3D晶体4，其中金属杯[4]芳烃结构单元作为新的4-连接节点，Cd（II）和HL的组合形成8连通C（2）-对称M（4）（HL）（4），其构造5的α-Po网。值得注意的是，这些大的M（4）（HL）（4）单元是金属有机网络的分级组装中潜在的高度连接的构建块。磁性研究揭示了M（4）（HL）（4）为1-4的反铁磁相互作用。采用等边四边形各向同性模型结合分子场近似（J = -4.00（2）、-3.39（2）和-2.72（3）cm（-1））分析了1、3和4的磁性数据，它们都含有同分异构的Ni（4）（HL）（4）单元，在结构和磁性之间进行了更强的比较。5的发射是奇数的，这可能与配体HL的双螯合方式和Cd（II）的罕见配位几何结构有关。此外，这些化合物的热稳定性和气体吸附性能进行了测试。
Five interesting metal-organic nanostructures and networks, [Ni(4)(HL)(4)(bpy)(py)(H(2)O)(5)](2) x 0.5 H(2)O (1), [Co(4)(HL)(4)(bpy)(py)(H(2)O)(5)](2) x 0.5 H(2)O (2), [Ni(4)(HL)(4)(H(2)O)(7)](n) x nH(2)O (3), [Ni(4)(HL)(4)(bpy)(2)(H(2)O)(4)](n) (4), and [Cd(4)(HL)(4)(H(2)O)](n) (5), were synthesized hydrothermally [H(3)L = 2-(pyridin-2-yl)-1H-imidazole-4,5-dicarboxylate acid, py = pyridine, and bpy = 4,4'-bipyridine]. Intriguingly, all compounds consist of novel metallacalix[4]arene building blocks M(4)(HL)(4), where doubly deprotonated HL in the same bichelating fashion of mu-kN,N':kO,N'' displays a strong coordination orientation by cooperation of the 4,5-imidazoledicarboxylate and 2-pyridyl groups. Very interestingly, the symmetry of M(4)(HL)(4) and the linkage styles between metal nodes and HL in M(4)(HL)(4) are sensitive to the reaction conditions, and the resulting structural motifs vary with secondary ligands and metal nodes. In 1 and 2, two C(1)-symmetric M(4)(HL)(4) units are bpy-bridged into dimeric chiral nanomolecules with two different cavities. As deprotonated with NaOH, the combination of Ni(II) and HL forms a pseudo-S(4)- or S(4)-symmetric M(4)(HL)(4), which further assembles into 1D chiral crystals 3 or rare 3D crystals 4 of bpy-bridged 5-fold interpenetrating diamondoid architecture with metallacalix[4]arene building blocks as novel 4-connecting nodes, and the combination of Cd(II) and HL forms an 8-connected C(2)-symmetric M(4)(HL)(4) that fabricates the alpha-Po net of 5. Notably, those large M(4)(HL)(4) units are potentially highly connected building blocks in a hierarchical assembly of metal-organic networks. Magnetic studies disclose antiferromagnetic interactions in M(4)(HL)(4) of 1-4. The magnetic data for 1, 3, and 4, all containing isomeric Ni(4)(HL)(4) units, are analyzed by an equilateral quadrangle isotropic model combined with the molecular-field approximation with J = -4.00(2), -3.39(2), and -2.72(3) cm(-1), respectively, presenting a stronger comparison between the structure and magnetism. The emission of 5 is odd, which perhaps is relative to the bichelating fashion of ligand HL and a rare coordination geometry of Cd(II). Moreover, the thermal stability and gas sorption properties of these compounds were measured.