报告题目：Finding Hydrides - neutron diffraction applied to metal clusters and strings
报告人： Dr. Alison Edwards
Bragg Institute @ Australian Nuclear Science and Technology Organization
时间： 12月13日(周五) 上午10:30
地点： 卢嘉锡楼报告厅（202）
以下是报告的摘要部分：
Neutron diffraction has particular advantages over X-ray diffraction in a number of regards: the method is very sensitive to the hydrogen atom and can often differentiate between atoms of similar atomic number e.g. C vs N, N vs O or Co vs Ni. In addition the penetrance of a neutron beam allows interrogation of crystals enclosed inside pressure cells, magnetic cells and extreme temperature control environments.
Our single crystal neutron diffractometer KOALA is presently the leading instrument in the world for application to questions in chemical crystallography where the samples obtainable challenge a major disadvantage of the method – crystals must be larger than can be used for X-ray studies – at least 0.1 mm3.
We have been in operation now since 2009 and have reached a point where we can routinely handle challenging structural problems in chemical crystallography where the additional information obtained from neutron diffraction is vital to the correct structure identification and refinement. A selection of cases demonstrating these applications will be presented. In particular the presence (or absence) of hydride in materials with exotic oxidation states – e.g. Mg+1 will be discussed. The presence of hydride in group 11 molecular nanoclusters prepared from reactions in which borohydride is present in excess will also be demonstrated.
H(center)@Cu4(fluxionaltetrahedron)@H6(octahedron)@Cu24(rhombicuboctahedron)
@H8(cube)@S24 (truncated octahedron)
欢迎感兴趣的老师与学生参加，谢谢 ！
固体表面物理化学国家重点实验室
biwn必赢
2013-12-11
