MOLECULAR MATERIALS EXHIBITING MAGNETIC CHIRAL ANISOTROPY II

根据定义，分子材料是由分子“构建块”制成的，其中分子起源清楚地存在于最终材料中。它们的模块化性质意味着它们可以在非常温和和受控的条件下以合理的方式制造。然后，物理性质作为组成分子和任何非共价分子间相互作用的函数出现。因此，材料的分子方法提供了很大的灵活性，可以使用化学来改变组成分子，以调整物理特性。也可以选择为产品带来互补特性的分子，从而产生多功能材料。如果这些性质彼此协同作用以产生可能难以以其他方式获得的进一步性质，则这是特别有趣的。例如，基于阳离子有机硫族化合物分子（导电组分）与磁性抗衡离子的盐，已经制备了磁性分子超导体，我们建议使用这类分子材料路线来制备具有磁手性各向异性（MCA）的材料。MCA预计将出现在手性材料中，并具有显着的导电性。该效应意味着它们的电阻根据电流的方向或施加的磁场的方向而不同。我们的方法是制备导电离子自由基盐，其中一个或两个离子是手性的。在本研究中，我们将合成一系列非手性阳离子和手性阴离子的盐。我们的方法将独特地着眼于一系列手性阴离子，以前没有在这个领域中使用，具有不同的拓扑结构和功能。这些阴离子被设计为通过分子间相互作用促进晶格中手性的表达。显示MCA的材料可能在新的电气设备中很重要，因为电流取决于由磁场引起的电子极化，这是自旋电子学的基础。

Molecular materials are, by definition, made from molecular 'building blocks' in which the molecular origins are clearly present in the final material. Their modular nature means that they can be made in a rational manner under very mild and controlled conditions. The physical properties then emerge as a function of the constituent molecules and any non-covalent intermolecular interactions. Therefore, a molecular approach to materials offers great flexibility to use chemistry to change the constituent molecules in order to tune the physical properties. It is also possible to choose molecules that bring complementary properties to the product, leading to multifunctional materials. This is especially interesting if these properties act in synergy with each other to produce a further property that may be difficult to obtain otherwise. For example, magnetic molecular superconductors have been made based on salts of cationic organochalcogenide molecules (the electrically conducting component) with magnetic counterions.We propose to use this kind of molecular materials route to prepare materials that exhibit Magneto-chiral Anisotropy (MCA). MCA is predicted to appear in materials that are chiral and have significant electrical conductivity. The effect means that their electrical resistance is different depending on the direction of current flow or on the direction of an applied magnetic field. Our method is to prepare conducting ion radical salts where one or both of the ions are chiral. In this pilot study we will synthesise a series of salts combining achiral cations and chiral anions. Our approach will uniquely look at a range of chiral anions, not previously used in this field, which have different topologies and functionality. These anions are designed to promote the expression of chirality in the lattice through intermolecular interactions. A material that exhibits MCA is likely to be important in new electrical devices since the current flow depends on the electron polarisation as induced by a magnetic field, which is the basis of spintronics.