Switchable Multifunctional Materials

对处理时间和数据量的期望正随着能源需求呈指数级增长。解决这一问题的关键是少花钱多办事，需要更快、更低功耗的电子设备。分子（例如纳米磁体）或二维（例如石墨烯）材料已显示出巨大的磁性/导电特性;使用少量能量触发或利用这些特性可以大幅降低能耗。因此，在寻求用作传感器、显示器等的上级下一代功能材料的过程中，其中物理性质可以切换的系统引起了极大的兴趣。为了在商业上可行，响应部分必须在两个（或更多个）状态之间可逆地相互转化以确保双链的存在。（或多稳态）状态（例如二进制代码中的0和1）。还必须开发耦合响应和功能单元的方法，以生产满足各种应用要求的可切换材料。自旋交叉（SCO）配合物由于其固有的双稳性，在外界刺激（如光、温度、压力）的作用下，可以在低自旋磁态（LS）和高自旋磁态（HS）之间进行转换，是实现分子电子学和自旋电子学的理想材料。 该提案的目标是通过设计开发新材料，以利用有机/无机系统的关键属性及其在分子电子学中的应用。虽然合理的设计允许获得具有新功能的新材料，这些新功能结合了联合收割机的磁性、光学和传输特性，但物理特性对固态包装的依赖性仍然是一个挑战。这在SCO系统中尤其相关，因为充分利用这些材料的努力揭示了控制固态堆积的重要性和困难性，因此有针对性的宏观性质，以弥合实验室和现实之间的差距。SCO材料的实际应用需要强的、突变的或滞后的协同效应。我们将通过配体设计和使用共轭连接体来增强分子间的相互作用来实现这一点，1）多核SCO络合物和2）氧化还原活性霍夫曼型框架和普鲁士蓝-霍夫曼共混物;这些特征也有望通过加强响应和功能部分之间的通信来赋予SCO系统多功能性，并在固态下进行受控组装。由于光辐射的高空间和时间分辨率，LS和HS状态之间的相互转换可以通过光诱导自旋跃迁以高效率和良好的可逆性实现。设计具有磁性和光学双稳性的材料，并将这些特征与其他物理属性（例如孔隙率）相结合，可以探索智能多功能材料，其中可以通过外部刺激来控制属性。

Expectations of processing times and volumes of data are increasing exponentially as are energy demands. Key to addressing this is to do more with less, requiring faster and lower power electronics. Molecular (e.g. nanomagnets) or two-dimensional (e.g. graphene) materials have shown tremendous magnetic/conducting properties; triggering or harnessing these with the use of a small amount of energy can drastically cut energy consumption. Thus, systems in which physical properties can be switched is of great interest in the quest for superior next-generation functional materials to be employed as sensors, displays, etc. While switchable materials are intriguing fundamentally, to be commercially viable the responsive moiety must reversibly interconvert between two (or more) states to ensure the existence of bistable (or multistable) states (e.g. 0 and 1 in binary code). A method to couple the responsive and functional units must also be developed to produce switchable materials that satisfy the requirements of various applications. Thanks to their inherent bistability, spin crossover (SCO) complexes in which external stimuli (e.g. light, temperature, pressure) can induce switching between low (LS) and high (HS) spin magnetic states are promising candidates for the realization of molecule-based electronics and spintronics.    This proposal targets new materials by design to exploit key attributes of organic/inorganic systems and their implementation into molecular electronics. While rational design permits access to novel materials with new functionalities that combine magnetic, optical and transport properties, the dependence of physical properties on solid-state packing remains a challenge. This is especially pertinent in SCO systems, as efforts to fully harness these materials reveal the importance and difficulty of controlling solid-state packing, and hence targeted macroscopic properties in order to bridge the gap between laboratory and reality. Practical application of SCO materials requires strong, abrupt or hysteretic cooperativity. We will achieve this by enhancing intermolecular interactions through ligand design and the use of conjugated linkers in the generation of 1) polynuclear SCO complexes and 2) redox active Hofmann-type frameworks & Prussian-blue-Hofmann blends; features that are also anticipated to render multifunctionality to SCO systems by strengthening communication between the responsive and functional moieties coupled with controlled assembly in the solid-state. Given the high spatial and temporal resolution afforded to photoirradiation, interconversion between LS and HS states can be realized with high efficiency and good reversibility via light-induced spin transitions. Designing materials with magnetic and optical bistabilities, and combining these features with other physical attributes (e.g. porosity), enables exploration of smart multifunctional materials where the properties can be controlled via external stimuli.