Study on synthesis, structure and physical properties of metal endohedral C_<60>, and its development to new materials

金属内嵌C_<60>的合成、结构、物理性能研究及其新材料开发

• 批准号: 11165227
• 负责人: KUBOZONO Yoshihiro
• 金额: $ 10.5万
• 依托单位: Okayama 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-11165227/
• 关键词: M@C_<60>; XANES; EXAFS; structure; electoronic state; superconductivity; physical property; 金属内包C60; 原子価; XAFS; 吸収スペクトル; 錯形成; 電子移動

Purified samples of metal endohedral C_<60> (M@C_<60>) have been prepared through the present project, and their structure and physical properties have been studied by XANES, EXAFS, Raman, UV-VIS-Near IR absorption, ESR and static susceptibility measurements. Large amounts of soots containing Eu@C_<60> and Dy@C_<60> were synthesized by arc-heating of metal oxide / graphite composite rods. The soot of Eu@C_<60> was sublimed at 450℃ under 10^<-6> Torr in order to eliminate Eu endohedral higher fullerenes, and the sublimate obtained was dissolved into a distilled aniline by a supersonic irradiation. On the other hand, the soot of Dy@C_<60> was directly dissolved into the distilled aniline. After repeating high performance liquid chromatography (HPLC) five times, the fraction exhibiting a single peak in the HPLC profile was collected, and the sample quality was checked by TOF-mass spectrum. The purity of Eu@C_<60> and Dy@C_<60> samples was 〜 99 %. The XANES of Eu@C_<60> and Dy@C_<60> showed that the valences of Eu and Dy were +2 and +3, respectively. The valences are accordance with those of Eu@C_<82> and Dy@C_<82>. The distance between Dy and the first nearest C atoms (Dy-C(1), and that between the Dy and the second nearest C atoms (Dy-C(2)) were determined to be 2.39(1) and 2.67(3) Å, respectively, on the basis of Dy L_<III>-edge EXAFS. The results show that the Dy atom lies on five-membered ring inside C_<60> cage ; the Dy is located at the off-center position by 1.25 Å. The Ag(2) Raman peak of Dy@C_<60> was observed at 1450 cm^<-1>. This shows that three electrons transfer from the Dy to the C_<60> cage. The ESR of Dy@C_<60> exhibited the g-factor of 2.0050 and line width of 4.5 G at 298 K. The ESR of Dy^<3+> was observed at 4.0 K, which implies that the spin of C_<60> appears by three-electrons transfer from Dy atom. The study on structure and physical properties of M@C_<60>・carbon nanotube hybrid materials in nanometer scale is now in progress.

本课题制备了金属内配体C_<60>（M@C_<60>）的纯化样品，并通过XANES、EXAFS、拉曼、UV-VIS-近红外吸收、ESR和静态磁化率等测试手段对其结构和物理性质进行了研究。采用<60><60>电弧加热金属氧化物/石墨复合棒制备了大量含Eu@C_和Dy@C_的炭黑。在<60>450℃、10 ~ 4 Torr条件下，将Eu@C_的烟灰升华<-6>，除去Eu内包高级富勒烯，所得升华物用超声辐照溶解于蒸馏苯胺中。另一方面，Dy@C_的烟灰<60>直接溶解在蒸馏的苯胺中。在重复高效液相色谱（HPLC）五次后，收集在HPLC图谱中显示单峰的级分，并通过TOF-质谱检查样品质量。Eu@C_<60>和Dy@C_<60>样品的纯度均在99%以上。Eu@C_<60>和Dy@C_<60>的XANES分析表明，Eu和Dy的价态分别为+2和+3。化合物的价态与Eu@C_<82>和Dy@C_的价态一致<82>。利用DyL_edgeEXAFS方法，测得Dy与第一近邻C原子的距离（Dy-C（1））和Dy与第二近邻C原子的距离（Dy-C（2））分别为2.39（1）和2.67（3）nm<III>。结果表明，Dy原子位于C_2笼内的五元环上<60>，Dy原子位于偏离中心1.25 π的位置。在1450 cm-2处观察到Dy@C_的Ag（2）拉曼峰<60><-1>。这表明三个电子从Dy转移到C_<60>笼。Dy@C_的ESR谱<60>在298 K时的g因子为2.0050，谱线宽度为4.5 G。在4.0 K下观察到Dy^&lt;3+&gt;的ESR谱，表明<60>Dy原子的三电子转移是C_的自旋。纳米尺度的M@C_ ·碳纳米管杂化材料的结构和物理性能的研究<60>正在进行中。

项目成果

久保園芳博・高林康裕 他5名: "Metal-Insulator transition at 50 K in Na_2C_<60>"Physical Review. B59(23). 15062-15069 (1999)

Yoshihiro Kubozono、Yasuhiro Takabayashi 等 5 人：“Na_2C_<60> 中 50 K 时的金属-绝缘体转变”B59(23) (1999)。

宇留賀朋哉・・・久保園芳博・・・(著者18名中9番目): "The XAFS Beamline at Spring-8"Journal of Synchrotron Radiation. 6. 143-145 (1999)

Tomoya Uruga...Yoshihiro Kubozono...（18 位作者中的第 9 位）：“Spring-8 的 XAFS 光束线”同步辐射杂志 6. 143-145 (1999)。

Y. Kubozono, Y. Takabayashi, T. Kambe, S. Fujiki, S. Kashino and S. Emura: "Structure and Physical Properties of Na_4C_<60> under Ambient and High Pressures"Phys. Rev.. B63. 45418-45426 (2001)

Y. Kubozono、Y. Takabayashi、T. Kambe、S. Fujiki、S. Kashino 和 S. Emura：“常压和高压下 Na_4C_<60> 的结构和物理性质”Phys。

Y. Kubozono, Y. Takabayashi, S. Kashino, M. Kondo, T. Akasaka, K. Kobayashi, S. Nagase and S. Emura: "Structure of La_2@C_<80> Studied by La K-edge XAFS"Chem. Phys. Lett.. 335. 163-169 (2001)

Y. Kubozono、Y. Takabayashi、S. Kashino、M. Kondo、T. Akasaka、K. Kobayashi、S. Nagase 和 S. Emura：“La K-edge XAFS 研究的 La_2@C_<80> 的结构”化学

久保園芳博 他6名: "Structure and physical properties of Eu@C_<60> dolid"Recent advances in the chemistry and physics of fullerene and fullerene related materials. 298-308 (2000)

Yoshihiro Kubozono等6人：“Eu@C_<60> dolid的结构和物理性质”富勒烯和富勒烯相关材料的化学和物理的最新进展298-308（2000）。