Assembling magnetic nanowires into networks: a layered CoII carboxylate coordination polymer exhibiting single-chain-magnet behavior.
Assembling magnetic nanowires into networks: a layered CoII carboxylate coordination polymer exhibiting single-chain-magnet behavior.
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DOI：
10.1002/anie.200601349
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发表时间：
2006-09
影响因子：
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通讯作者：
Yan‐Zhen Zheng;M. Tong;Wei-Xiong Zhang;Xiao‐Ming Chen
中科院分区：
文献类型：
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作者：
Yan‐Zhen Zheng;M. Tong;Wei-Xiong Zhang;Xiao‐Ming Chen
近年来，化学家和物理学家共同推动了分子纳米磁体的快速进展。[1]自 20 世纪 90 年代首次发现单分子磁体 (SMM) 以来，[2] 这一领域的令人兴奋的发现包括单链磁体（SCM，或所谓的磁性纳米线）[3] 和氢键 SMM 二聚体，[4]，它们可以被视为通过分子间磁相互作用对 SMM 的扩展。[4, 5] 这些观察结果鼓励化学家将 SMM 构建或定制为 扩展网络，希望通过共价连接体介导的某些协同效应可以改善原始单元的量子特性。[5-7]这个想法导致了各种有趣的SMM网络，表现出从经典磁性到量子磁性的特性[6, 7]，并为研究分子间相互作用对磁化反转能垒所产生的行为的影响提供了有用的课题。[4-7]与快速发展相反 与 SMM 网络相比，SCM 网络受到显着限制，这可能是由于难以排列这些磁性纳米线，同时保持链内与链间磁相互作用的比例足够大，以“冻结”一维 (1D) 磁化并阻止 3D 排序。 [3]因此，使用适当的共价连接体非常重要，它至少应具有两个特征：1）多主题结构以共价连接链； 2）磁性“惰性”，有效防止链之间的磁相互作用。由于σ键连接体是自旋载流子的明显较弱的介体，[8]明智地选择σ键合双位连接体的晶体工程可以使我们将1D伊辛铁或亚铁磁链共价连接成2D或3D网络，而不会显着恶化一维磁性 2D 或 3D 结构中的 SCM，尽管迄今为止还没有报道过真正的例子。在这方面，反式1, 2-环己烷二甲酸酯（反式1, 2-chdc）是一个很好的候选者，因为由于交替效应，它被证明是一种非常弱的磁介质[9]。 [8]作为我们不断寻找新的磁性配位聚合物的一部分，[10]我们选择这种配体作为结构连接子和磁性分离器，以将磁各向异性链纳入更高维的网络。我们用trans-1, 2-chdc制备层状配位聚合物
Chemists and physicists have jointly pushed the rapid progress of molecule-based nanomagnets in recent years.[1] Since the first discovery of single-molecule magnets (SMMs) in the 1990s,[2] exciting discoveries in this area have included single-chain magnets (SCMs, or so-called magnetic nanowires)[3] and a hydrogen-bonded SMM dimer,[4] which can be regarded as expansions of SMMs by intermolecular magnetic interactions.[4, 5] These observations have encouraged chemists to construct or tailor SMMs into an extended network with the hope that certain cooperative effects mediated by covalent linkers could improve the quantum properties of the original units.[5–7] This idea has led to a variety of interesting SMM networks exhibiting properties from classical to quantum magnetism [6, 7] and provided useful subjects for studying the effects of intermolecular interactions on the behavior arising from the energy barrier to magnetization reversal.[4–7] In contrast to the rapid development of SMM networks, SCM networks are significantly restricted, which may be attributable to the difficulty in arranging these magnetic nanowires while maintaining a sufficiently large ratio of intra-to interchain magnetic interaction to “freeze in” one-dimensional (1D) magnetization and prevent 3D ordering.[3] Thus, it is important to use proper covalent linkers, which should have at least two features: 1) multitopic structure to covalently link the chains; 2) magnetically “inertness” to efficiently prevent magnetic interactions between the chains.As σ-bonding linkers are significantly weaker mediators of the spin carriers,[8] crystal engineering with a judicious choice of σ-bonding ditopic linkers may allow us to covalently link 1D Ising ferro-or ferrimagnetic chains into 2D or 3D networks without significant deterioration of the one-dimensional magnetism of the SCMs in the 2D or 3D structures, although no genuine example has been reported so far. In this regard, trans-1, 2-cyclohexanedicarboxylate (trans-1, 2-chdc) is a good candidate, since it was demonstrated to be a very weak magnetic mediator [9] due to alternation effects.[8] As part of our ongoing search for new magnetic coordination polymers,[10] we chose this ligand as a structural linker and magnetic separator to incorporate magnetic anisotropic chains into a higher dimensional network. We have used trans-1, 2-chdc to prepare laminated coordination polymer