U.S.-Japan Cooperative Research: Solid-State Dynamics

该奖项为加州大学圣地亚哥分校化学系David N Hendrickson教授和日本大阪大学化学热力学实验室Michio Sorai教授在固态动力学方面的持续合作研究项目提供支持。晶体中与配体、反离子甚至溶剂化物分子相关的动力学的开始可以显著影响涉及固态过渡金属配合物的几种现象。混合价配合物中的分子内电子转移、自旋交叉配合物中的自旋态相互转换以及铜和镍配合物中的热致变色是目前研究的现象。在所有这些现象中，固态中的分子间相互作用对控制事件起着重要作用。对这些相变中涉及的动力学开始的研究将大大有助于阐明控制这些现象的因素。热容测量和各种光谱技术被用来描述上述现象中涉及的宏观和微观细节。热力学研究是阐明一种现象的能量和熵方面的有力工具，从中人们可以获得关于相变是否存在的更好证据。此外，基于相变熵，有可能发现光谱和结构研究无法检测到的相变中涉及的微观过程。另一方面，光谱学和x射线衍射为我们提供了原子或电子水平上非常详细的微观信息。本提案的目的是将这些技术结合在一起，以研究电子直接或间接发挥重要作用的相变机制。本项目涉及的两个研究小组的技能既全面又互补；日本集团在宏观量热研究方面具有相当的专业知识，美国集团在微观光谱和结构研究方面具有类似的专业知识。由于他们的背景非常不同，亨德里克森教授和索拉伊教授将为一个给定的有序-无序过渡模型的发展带来截然不同的视角。如果成功，这个项目将对这个复杂的地区作出相当大的贡献。

This award provides support for a continuing cooperative research project on solid-state dynamics, between Professor David N Hendrickson, Department of Chemistry, University of California, San Diego, and Professor Michio Sorai, Chemical Thermodynamics Laboratory, Osaka University, Japan. The onset of dynamics associated with ligands, counterions and even solvate molecules in crystals can dramatically affect several phenomena involving transition metal complexes in solid state. Intramolecular electron transfer in mixed- valence complexes, spin-state interconversion in spin- crossover-complexes, and thermochroism in copper and nickel complexes are current phenomena being studied. In all these phenomena, intermolecular interactions in the solid state are important in controlling the events. A study of the onset of the dynamics involved in these phase transitions will help considerably to elucidate the factors controlling these phenomena. Heat capacity measurements and a variety of spectroscopic techniques are being employed to delineate the macroscopic and microscopic details involved in the above phenomena. Thermodynamic studies serve as a powerful tool to elucidate energetic and entropic aspects of a phenomenon, from which one can gain better evidence as to whether a phase transition exists or not. Moreover based on the transition entropy, it is possible to discover the microscopic processes involved in a phase transition that spectroscopic and structural studies fail to detect. On the other hand, spectroscopies and X-ray diffraction provide us with very detailed microscopic information at the atomic or electronic level. The aim of this proposal is to bring together these techniques in order to study the mechanisms of those phase transitions in which electrons play, either directly or indirectly, important roles. The skills of the two research groups involved in this project are both comprehensive and complementary; the Japanese group having considerable expertise in macroscopic calorimetric studies and the US group having similar expertise in microscopic spectroscopies and structural studies. Because of their very different backgrounds Professors Hendrickson and Sorai will bring quite different perspectives to developing a model for a given order-disorder transition. If successful, this project should make a considerable contribution to this complex area.