Flexible linkers and dinuclear metallic nodes build up an original metal–organic framework
Flexible linkers and dinuclear metallic nodes build up an original metal–organic framework
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DOI：
10.1039/c3ce40506k
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发表时间：
2013-06
期刊：
影响因子：
3.1
通讯作者：
A. Vlad;M. Zaltariov;S. Shova;G. Novitchi;C. Varganici;C. Train;M. Cazacu
中科院分区：
文献类型：
--
作者：
A. Vlad;M. Zaltariov;S. Shova;G. Novitchi;C. Varganici;C. Train;M. Cazacu
通过将H2 tmds和咪唑依次加入到醋酸铜（II）溶液中，合成了分子式为[Cu 2（μ3-tmds）2（imH）4]·H2 tmds（imH =咪唑; H2 tmds = 1，3-双（3-羧丙基）四甲基二硅氧烷）1的金属有机骨架（MOF）.化合物1的晶体结构已通过单晶X射线衍射进行了研究。晶体属C2/c单斜空间群。该晶体是由一个扩展的配位网络欢迎H2 tmds分子。该网络包含桨轮式的二铜（II）部分，其中两个铜原子被两个tmds 2 −阴离子的羧酸根基团之一桥接。其配位球的底面由两个咪唑分子补充，而顶端位置由相邻tmds 2 −阴离子的第二个羧酸根基团的一个氧原子占据，导致金属离子的整体四方锥环境。这些灵活的tmds 2 −二价阴离子的短桥和长桥模式建立了一个复杂的二维配位网络，其中节点是双核簇而不是简单的金属中心。在网络中发现了H-键，其中咪唑作为H-键供体，tmds 2-作为H-键受体，导致配体的顺式构象。该配位网络进一步与H2 tmds分子氢键结合，形成了一个混合配位和氢键的三维超分子网络。变温磁化率测量揭示了桨轮双核单元内铜离子之间的反铁磁相互作用（J = −34.4（2）cm−1; H = − 2 JS 1 S 2）。
A Metal–Organic Framework (MOF) of formula [Cu2(μ3-tmds)2(imH)4]·H2tmds (imH = imidazole; H2tmds = 1,3-bis(3-carboxypropyl)tetramethyldisiloxane) 1 has been synthesized by successive additions of H2tmds and imidazole to a solution of copper(II) acetate. The crystal structure of compound 1 has been investigated by single-crystal X-ray diffraction. It crystallizes in the C2/c monoclinic space group. The crystals are composed of an extended coordination network welcoming H2tmds molecules. The network contains paddle-wheel dicopper(II) moieties where the two copper atoms are bridged by one of the carboxylate groups of two tmds2− anion. The basal plane of their coordination sphere is complemented by two imidazole molecules whereas the apical position is occupied by one oxygen atom of the second carboxylate group of a neighboring tmds2− anion leading to an overall square-pyramidal environment of the metal ions. These short and long bridging modes of the flexible tmds2− dianion build up a complex bidimensional coordination network where the nodes are dinuclear clusters rather than simple metal centres. H-bonds are found within the network with imidazole as a H-bond donor and tmds2− as a H-bond acceptor leading to a cis-oide conformation of the ligand. The coordination network is further H-bonded to H2tmds molecules leading to an overall three-dimensional supramolecular network mixing coordination and hydrogen bonds. Variable-temperature magnetic susceptibility measurements reveal antiferromagnetic interactions between the copper(II) ions within the paddle-wheel dinuclear units (J = −34.4(2) cm−1; H = −2JS1S2).