New Chemistry and Physics from Transition-Metal Cyanides

这项研究计划的目的是描述具有有趣的结构和物理特性的新型固态材料。这种材料是过渡金属氰化物，由简单的结构建筑单元连接而成。通过以不同的方式组装这些单元，我们可以设计和生产各种包含链、层和三维金属氰化物骨架的新结构。其中一些氰化物材料含有不寻常的配位几何结构的过渡金属离子，只有在生物相关的系统中才能发现。另一些则表现出奇怪的热行为，如“负热膨胀”，即它们在加热时收缩而不是膨胀。另一类氰化物充当分子开关。这些开关通过原子间距离、几何形状、颜色和磁性行为的变化来工作。在所有这些工作的基础上，需要了解材料在原子尺度上的详细结构，以便解释它们的化学和物理行为。大多数这些材料的无序性质使得它们的结构特征成为一项挑战，这在家庭实验室中是无法实现的。为了实现我们的目标，我们需要使用最先进的中子和同步加速器设施，幸运的是，英国在ISIS和钻石拥有这些设施。使用这些设备，我们还将能够确定结构如何随温度和压力变化。了解结构如何随温度和压力的变化对于理解这些材料以及设计具有潜在技术重要性的新材料都很重要。

The aim of this research program is to characterise new solid-state materials with interesting structural and physical properties. The materials, transition-metal cyanides, are constructed by joining together simple structural building units. By assembling such units in different ways, we can design and produce a variety of new structures containing chains, layers and three-dimensional metal-cyanide frameworks. Some of these cyanide materials contain transition-metal ions in unusual coordination geometries, only found to date in biologically related systems. Others exhibit curious thermal behaviour such as 'negative thermal expansion', where they contract rather than expand on heating. A further class of cyanides act as molecular switches. The switches operate through changes in interatomic distances, geometry, colour and magnetic behaviour. Underlying all this work is the need to know the detailed structures of the materials on the atomic scale in order to explain their chemical and physical behaviours. The disordered nature of most of these materials makes their structural characterisation a challenge, which cannot be achieved in the home laboratory. To succeed in our aims, we need to use state-of-the art neutron and synchrotron facilities, which fortunately, the UK possesses at ISIS and Diamond. Using these facilities, we will also be able to determine how structures change with temperature and pressure. The knowledge of how structure evolves as a function of temperature and pressure is important in understanding both these materials and for the design of new materials of potential technological importance.