权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

The charge density study of fullerenen compounds by the MEM

MEM 对富勒烯化合物电荷密度的研究

基本信息

批准号：
11165226
负责人：
TAKATA Masaki
金额：
$ 20.22万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research on Priority Areas (A)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11165226/
关键词：
MEM Fullerene Charge Density Metallofullerene X-ray Structure Analysis Powder Diffraction Synchrotron Radiation

项目摘要

This research project had been carried out to reveal the experimental charge densities of fullerene compounds using the Maximum Entropy Method(MEM) combined with Rietveld analysis, which is called as MEM/Rietveld analysis. Consequently, the work was achieved successfully and revealed the structures in charge density level for the novel endohedral metallofullerenes. Among them, the success of the structural analysis of IPR(Isolated Pentagon Rule)-violated metallofullerene, Sc_2@C_<66>, was one of the greatest results in this project. This has been published in Nature (408(2000)426)and reported in some news papers. The result gave the breakthrough in the criteria for the stable geometry of the metallofullerene cage structure, that is, the IPR is not necessarily a test for the stable geometry of endohedral metallofullerenes In addition, it was found that the charge-transfer interaction between the Sc_2 dimer and the fused pentagons significantly decreases the strain energies caused by the pair of fused pentagons and thus stabilizes the fullerene cage. Another important result is the structure determination of the Sc_2C_2 cluster encapsulated in C_<84> for Sc_2C_2@C_<84>. This is the first report of the structure of fullerene encapsulating Sc-carbide molecule and has an impact on the research of the novel endo-fullerene. The result was published in Angew. Chem. Int'l. Ed. 40 (2001) 397 as the very important paper and the charge density of Sc_2C_2@C_<84> was appeared as the cover picture of Angew. Chem. Int'l. Ed. 40 No.2(2001).No doubt the experimental structural information we provided through this project gave one of the greatest forward push to a research of fullerene compounds.

本研究利用最大熵方法（MEM）结合Rietveld分析（简称MEM/Rietveld分析）揭示了富勒烯化合物的实验电荷密度。因此，成功地完成了这项工作，并揭示了新的内嵌金属富勒烯的电荷密度水平的结构。其中，违反IPR（孤立五角形规则）的金属富勒烯Sc_2@C_的结构分析的成功<66>是该项目的最大成果之一。这已发表在自然（408（2000）426）和一些新闻报纸报道。实验结果突破了金属富勒烯笼结构稳定几何构型的判据，即IPR不一定是对内嵌金属富勒烯稳定几何构型的检验。此外，发现Sc_2二聚体与稠合五边形之间的电荷转移作用显著降低了由稠合五边形对引起的应变能，从而稳定了富勒烯笼。另一个重要的结果是确定了Sc_2C_2@C_的Sc_2C_2团簇的结构<84><84>。这是首次报道富勒烯包覆Sc-碳化物分子的结构，对新型富勒烯的研究具有重要意义。结果发表在Angew上。国际化学Ed.40（2001）397作为非常重要的论文，Sc_2C_2@C_的电荷密度<84>作为Angew的封面图片出现。国际化学毫无疑问，我们通过这个项目提供的实验结构信息对富勒烯化合物的研究起到了最大的推动作用。