Creation of New Organometallic Cluster and Reaction Dynamics

在上一财政年度研究结果的基础上，开展了以下两项研究：(1)发展了一种利用激光烧蚀金属有机化合物靶产生金属有机团簇的新方法，(2)用低电旋金属原子制备金属有机团簇及其电子结构的研究。此外，利用飞秒激光光谱仪研究了金属团簇的电子性质，根据我们以前对金属团簇产生机理的分析，揭示了金属有机团簇产生的速率决定步骤是一个电子自旋转化为较低的自旋。因此，使用有机金属化合物本身可以被认为是有效地产生有机金属原子簇的一种有前途的方法，因为化合物中金属原子的电子自旋较好地表现出较低的自旋态。当二茂铁分子是最典型的有机金属化合物之一，用激光烧蚀钒原子汽化时，成功地在气相中生成了二茂铁分子与钒原子交替堆积的聚二茂铁。由于碱金属原子倾向于较低的电子自旋，因此似乎很容易与碱金属原子形成有机金属团簇。事实上，C60-Na混合团簇的形成效率很高，电子结构可以描述为具有局部稳定几何结构的电荷转移络合物。三名日本成员曾出国访问加拿大国家研究委员会(NRC)，他们从事了金属团簇和有机金属团簇的飞秒激光光谱或Zeke光谱研究。另一方面，NRC的两位成员P.A.Hackett博士和D.M.Rayner博士加入了我们的小组，讨论了C60-Na的电子结构，并撰写了一篇关于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.