A Nanoscale Molecular Switch Triggered by Thermal, Light, and Guest Perturbation
A Nanoscale Molecular Switch Triggered by Thermal, Light, and Guest Perturbation
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DOI：
10.1002/anie.200805178
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发表时间：
2009-01-01
影响因子：
16.6
通讯作者：
Batten, Stuart R.
中科院分区：
文献类型：
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作者：
Duriska, Martin B.;Neville, Suzanne M.;Batten, Stuart R.
基于分子的磁性材料，如那些显示磁有序或自旋交叉(SCO)的材料，是数据存储和电子工业中有吸引力的元器件候选材料。[1]为了预期将其应用于电子设备，需要将下一代先进的磁性材料微型化到纳米级。虽然超分子自组装(也就是“自下而上”方法)的应用已经在大的单分子磁体的生产中取得了巨大的效果，[2]最近制造纳米尺度的自旋切换系统的努力已经集中在“自上而下”的方法和替代“自下而上”方法的方法上，例如纳米颗粒的生长。[3]还已经认识到，通过将SCO的性质结合到具有例如纳米孔性质的材料中，可以产生先进的、多功能的磁性材料。研究表明，纳米多孔聚合物骨架材料中客体的去除和/或交换可以导致SCO行为的显着变化，从而获得基于磁性的分子传感材料。在这里，我们报道了用“自下而上”的方法组装的纳米级分子金属-有机离散开关纳米球，它对包括温度、光和溶剂分子在内的一系列外部刺激显示出磁性响应。特别令人感兴趣的是它作为光敏磁器件的潜在应用，其中可以通过波长变化容易地选择磁性状态。这项工作还强调了通过固态客体交换和移除来操纵离散纳米无机分子的电子态的范围。用于构建金属-有机纳米球的方法如图1所示。所使用的有机配体[tris{3-(4-吡啶)-吡唑-1-基}氢化硼]((Tp4±py)？)包含以两个不同步骤为目标的初级和二级结合位点(图1a)。首先，利用中心的三(吡唑基)氢硼酸盐核在原位、组织前步骤中形成中性金属配体[Cui(Tp4±py)(CH3CN)](图1b)。这种构筑块在构象上稳定
Molecule-based magnetic materials, such as those that display magnetic ordering or spin crossover (SCO), are attractive candidates for components in the data storage and electronics industries.[1] Miniaturization of next-generation advanced magnetic materials to the nanometer scale is required for their anticipated incorporation into electronic devices. While the application of supramolecular self-assembly (that is, the “bottom-up” approach) has been used to great effect in the production of large single molecular magnets,[2] recent efforts to produce nanoscale spin-switching systems have been focused on “top-down” approaches and alternative methods to the “bottom-up” approach, such as nanoparticle growth.[3] It has also been realized that advanced, multifunctional magnetic materials may be generated through the incorporation of SCO properties into materials that have, for example, nanoporous natures.[4–6] In particular, it has been shown that guest removal and/or exchange in nanoporous polymeric framework materials can lead to remarkable changes in SCO behavior such that magnetism-based molecular sensing materials can be attained. Herein we report the assembly, by using a “bottom-up” approach, of a nanoscale molecular metal–organic discrete switching nanoball, which shows a magnetic response to a range of external stimuli, including temperature, light, and solvent molecules. Of particular interest is its potential application as a light-sensitive magnetic device in which an “on” or “off” magnetic state can be readily selected by wavelength variation. This work also highlights the scope for manipulating the electronic state of discrete nanometer-sized inorganic molecules through solid-state guest exchange and removal.The approach used to construct the metal–organic nanoball is outlined in Figure 1. The organic ligand employed,[tris {3-(4-pyridyl)-pyrazol-1-yl} hydroborate]((Tp4Àpy) À) contains primary and secondary binding sites that are targeted in two distinct steps (Figure 1a). Firstly, the central tris (pyrazolyl) hydroborate core is utilized in an in situ, preorganizational step to form the neutral metalloligand [CuI (Tp4Àpy)(CH3CN)](Figure 1b). This building block conformationally stabilizes