Study of the Correspondence in Electronic Structure between the Molecules Adsorbed on Surface and Their Model clusters

表面吸附分子与其模型团簇电子结构对应关系的研究

基本信息

批准号：
13640498
负责人：
MISAIZU Fuminori
金额：
$ 2.56万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

In this project, intracluster electron transfer from an alkali atom to constituent molecules and the following chemical reactions have been investigated by photoionization mass spectroscopy, negativeion photoelectron spectroscopy, photodissociation of cluster ions, and also by quantum chemical calculations. In the photoionization study, size-dependent stability of clusters is examined for the systems consisting of an alkali atom M (M=Li, Na, and K) and acrylonitrile (AN; CH2=CHCN) molecules These clusters are considered as microscopic models of initial systems for anionic polymerization reaction in the bulk solution. In the photoionization mass spectra of M(AN)_n^+, strong ion signals were observed commonly at n=3. This magic number can be explained by the electron transfer from the metal atom to vinyl molecules followed by intracluster anionic oligomerization to produce stable species with substituted cyclohexane ring structures. These clusters with n=3 were also found to be extraordi … More nary stable from the photodissociation experiments prior to photoionization. Quantum chemical calculation for Na(AN) based on density functional theory also supports the intracluster electron transfer from the metal atom to molecules.Along with the neutral systems noted above, intracluster reactions in the negative ions of the NaAN clusters have also been examined by mass-selected photoelectron spectroscopy. In this experiment, we obtained photoelectron spectra of cluster negative ions, which were produced by laser vaporization and mass selected in a TOF mass spectrometer, by using a magnetic-bottle TOF electron energy analyzer. The obtained photoelectron spectrum of Na(AN)_3- were found to have the similar band structure with that of (AN)_3- and also with that of the 1,3,5-cyclohexanetricarbonitrile molecular negative ion obtained by Kondow and his coworkers. This observation indicates that the excess electron in Na(AN)_3- promotes the intracluster anionic oligomerization and that the cyclic oligomer is produced as discussed for the neutral M-vinyl molecules systems. Less

在该项目中，luston内部从碱到征兵分子的转移以及通过光电量质谱法的下列化学现实。，Na和K）分子簇被认为是在M（AN）_n^+的光谱质谱中，用于散装溶液中的阴离子聚合重新进行的初始系统的微观模型。然后，在缩写内部的寡聚式上，带有n = 3的这些簇也可以从光解异位实验中稳定。在上面没有的中性系统的情况下，NAAN簇的簇内反应也通过质量 - 信号的质量分子进行了检查。（AN）_3-与（AN）_3-的带状结构相似，并且与Kondow和他的同事获得的1,3,5-循环分子负离子的结构相似。 Na（AN）_3-促进了簇内的阴离子寡聚，并且对中性M-乙烯基分子系统进行了较小的循环寡聚物。