MOLECULAR MATERIALS EXHIBITING MAGNETIC CHIRAL ANISOTROPY II

根据定义，分子材料是由分子“构建块”组成的，其中分子起源明显存在于最终材料中。它们的模块化特性意味着它们可以在非常温和和可控的条件下以合理的方式制造。物理性质随后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，以调整物理性质。也可以选择给产品带来互补特性的分子，从而产生多功能材料。如果这些属性相互协同作用，产生另一种可能难以获得的属性，这一点尤其有趣。例如，磁性分子超导体是基于带有磁性反离子的阳离子有机硫系分子（导电成分）的盐制成的。我们建议使用这种分子材料路线来制备具有手性磁各向异性（MCA）的材料。预计MCA会出现在具有手性和显著导电性的材料中。这种效应意味着它们的电阻是不同的，取决于电流流动的方向或施加磁场的方向。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都是手性的。在这项初步研究中，我们将合成一系列结合非手性阳离子和手性阴离子的盐。我们的方法将独特地研究一系列手性阴离子，这些阴离子以前没有在这个领域使用过，它们具有不同的拓扑结构和功能。这些阴离子旨在通过分子间相互作用促进晶格中手性的表达。表现出MCA的材料可能在新的电子设备中很重要，因为电流的流动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.