双钇金属富勒烯的分子结构及其内嵌原子簇环形运动状态的化学调控

项目名称： 双钇金属富勒烯的分子结构及其内嵌原子簇环形运动状态的化学调控

项目编号： No.20871043

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 金属学与金属工艺

项目作者： 廉永福

作者单位： 黑龙江大学

项目金额： 33万元

中文摘要： 本课题采用直流电弧放电合成和高效液相色谱分离的方法，成功获得了内嵌双钇金属富勒烯的系列纯品：Y2@C80（I）、Y2@C82（I,III、Y2C2@C82（I,III）、Y2@C90（I）和Y2@C92（I,II。利用Vis-NIR、CV、DPV、13CNMR和MALDI-TOF MS等表征手段系统地研究了Y2@C82 (III)和Y2C2@C82(III)的电子结构和分子结构。13C NMR证实两者碳笼同属于C82-C3v(8)结构，从首次检测出内嵌C2簇的13C NMR三重峰出发，推测内嵌YC2Y原子簇为菱形结构，并以C82-C3v(8)的C3轴旋转。我们注意Y2C2@C82的吸收峰位Y2@C82(III)的强吸收峰位有所蓝移，Y2C2@C82(III)也比Y2@C82(III)少一对氧化还原峰，Y2@C82(III)和Y2C2@C82(III)的13C NMR谱图有明显不同，这些都是由于C2物种的嵌入减少了转移到碳笼的电子数所致。对它们的光谱学和电磁学性质的深入研究，有可能建立起既能区分两类双金属富勒烯又能给出其内嵌原子簇环形运动信息的分析方法。

中文关键词： 富勒烯；金属富勒烯；结构；核磁共振

英文摘要： Dimetallofullerenes could be classified to two types in line with that whether pair of metal atoms or metal carbides are encapsulated into carbon cages.A series of diyttrium metallofulleres Y2@C80 (I), Y2@C82 (I,III), Y2C2@C82 (I,III), Y2@C90 (I) and Y2@C92 (I,II) were synthesized by DC arc-discharge method and isolated by high performance liquid chromatography technique,and their purity was estimated to be about 95% according to MALDI-TOF MS and HPLC analyses.The electronic and molecular structures of Y2@C82 (III) and Y2C2@C82 (III) were systematically studied by Vis-NIR spectrometry, cyclic voltammetry and 13C-NMR. It was confirmed that the cage of Y2C2@C82(III) is exactly the same as that of Y2@C82(III), i.e. C82-C3v(8), and the presence of C2 species in Y2C2@C82(III) was also detected with 13C-NMR as a triple signal. It is suggested that the endohedral YC2Y atom cluster forms a diamond structure and rotates along the C3 axis of C82-C3v (8).Because of the presence of C2 species, Y2C2@C82 (III) is blue-shifted in absorption spectrum, short of a pair of REDOX peak and markedly different in 13C NMR signals in comparison with Y2@C82 (III).Further detailed investigation on their spectroscopic,electronic and magnetic properties might lead to some analytical methods to distinguish the above two types of dimetallofullerens and to provide information on the circular motion of the encaged atom clusters.

英文关键词： fullerene;metallofullerene; structure; 13C-NMR