Creation of New Organometallic Cluster and Reaction Dynamics

本研究以上年度的研究成果为基础，进行了以下两项研究：（1）开发利用激光烧蚀有机金属化合物靶生成有机金属簇的新方法;（2）用低自旋金属原子生成有机金属簇，并研究其电子结构。此外，我们还利用飞秒激光光谱研究了金属团簇的电子性质，根据我们对团簇产生机理的分析，发现金属有机团簇产生的速率控制步骤是一个电子自旋向一个较低自旋的转变。因此，有机金属化合物本身的使用可以被认为是有效地产生有机金属簇的有希望的方法，因为化合物中的金属原子的电子自旋优选表现出较低的自旋状态。当一种典型的有机金属化合物二茂铁分子被激光烧蚀蒸发，同时另一种激光烧蚀钒原子时，在气相中成功地制备出二茂铁分子与钒原子交替堆积的聚二茂铁。由于碱金属原子更喜欢较低的电子自旋，似乎很容易与碱金属原子形成有机金属簇。实际上，C_（60）-Na混合团簇的形成效率很高，其电子结构可以用电荷转移复合物和局部稳定几何结构来描述。三名日本成员曾到国外访问加拿大国家研究理事会（NRC），从事金属团簇和有机金属团簇的飞秒激光光谱学和ZEKE光谱学研究。另一方面，P.A.博士的两名NRC成员。哈克特和D博士M. Rayner加入了我们的小组，讨论了C60-Na的电子结构，并写了一篇关于C60- Na团簇阴离子的光电子能谱的论文。

On the basis of the results in the preceding fiscal year, the following two studies were performed; (1) development of a new method for generation of organometallic clusters using laser ablation of organometallic compound target, (2) the production of organometallic clusters with metal atoms having low electro-spin and the study of their electronic structures. Moreover, the electronic properties of metal clusters were investigated by femto-second laser spectroscopy.According to our previous analysis on the production mechanism, it has been revealed that the rate determining step for the production of organometallic clusters is an-electron spin conversion into a lower spin. Thus, the use of the organometallic compound itself can be regarded as a promising way to generate the organometallic clusters efficiently, because the electron spin of metal atoms in the compound preferably exhibits a lower spin state. When a ferrocene molecule, which is one of the most typical organometallic compounds, was vaporized by laser ablation with another laser ablation of vanadium atoms, poly-ferrocene was successfully produced in gas phase, in which ferrocene molecules are piled up alternately with the vanadium atoms. Since alkali metal atoms prefer a lower electron spin, it seems easy to form organometallic clusters with the alkali metal atom. Indeed, C60-Na mixed clusters were formed efficiently, and it has been revealed that the electronic structure can be described as a charge transfer complex together with a local stable geometry.Three Japanese members have been abroad to visit National Research Council of Canada (NRC), and they have been engaged on either femto-second laser spectroscopy or ZEKE spectroscopy of metal clusters and organometallic clusters. On the other hand, two NRC members of Dr. P. A. Hackett and Dr. D. M. Rayner have joined our group to discuss the electronic structure of C60-Na and to write a paper on the photoelectron spectroscopy of C60- Na cluster anions.