STUDY ON PHYSICAL AND CHEMICAL STABILITIES OF METALLOFULLERENES PROVED BY NUCLEAR PHENOMENA

核现象证明金属富勒烯物理化学稳定性的研究

• 批准号: 10640550
• 负责人: SUEKI Keisuke
• 金额: $ 1.73万
• 依托单位: TOKYO METOROPOLITAN UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640550/
• 关键词: Metallofullerene; Nuclear reaction; Nuclear decay; Recoil atom; Retention yield; HPLC; Stability; Oxidation state; 中性子放射化; 放射線同位体; M@C_<82>; ホットアトム効果; 放射性同位体; 異性体; トレーサー

The unique problem posed by nuclear phenomena is the stability of carbon cages against nuclear reactions and nuclear decay. Knowledge of such property of carbon cages is important not only for radioactive labeling of fullerenes but also for investigating the physical and chemical stability of fullerene cages against sudden jerks and/or a sudden supply of a hung amount of recoil energy, and against the sudden change of nuclear charge of the cage or that of endohedral metal atoms.It can be considered that such "retention yield" is a complicated product of not only the survivability of the metallofullerenes against the recoil energy in the (n, γ) reaction, but also the stability against the gamma dose in the reactor of the fullerene molecules and chemical yield in each step of the chemical procedure applied to the sample after neutron irradiation. The ratios of retention yield observed for ィイD1169ィエD1Yb/ィイD1175ィエD1Yb and ィイD1153ィエD1Gd/ィイD1161ィエD1Gd have led to the conclusion that the thre … More shold energies for destruction of their M@CィイD282ィエD2 metallofullerenes following the recoiling phenomena associated with (n, γ) reaction are about 27-29 eV. The overall retention yield of 20 % in the reactor irradiation was deduced by the experiments on La@CィイD282ィエD2 that were aimed to cancel out the corrections requires for chemical yields during the chemical treatment.It is to further investigate the influence of radioactive decay process on the physical and chemical stability of metallofullerenes. It is concluded that the metallofullerenes which are stable during the chemical process of ordinary solvent extraction and HPLC separations in air are also stable against the β-decay and EC-decay process of the metal atom in the cage, as long as the oxidation state of the daughter nuclide remains the same with that of the parent nuclide within the same carbon cage. But if the oxidation state is changed by nuclear transformation, it is appeared to form chemically unstable metallofullerenes are formed as demonstrated in the β-decay of ィイD1177ィエD1Yb-ィイD1177ィエD1Lu where the oxidation state is likely to have changed from +2 to +3. However, the existence of a special kind of CィイD282ィエD2 carbon cage that forms chemically stable metallofullerenes with metal atoms of both +2 and +3 oxidation state is experimentally found for the first time by the study of EC decay of ィイD1146ィエD1Gd-ィイD1146ィエD1Eu. Less

核现象所带来的独特问题是碳笼对核反应和核衰变的稳定性。碳笼的这种性质的知识不仅对于富勒烯的放射性标记是重要的，而且对于研究富勒烯笼对突然的猛拉和/或突然供应大量的反冲能量的物理和化学稳定性也是重要的，对笼形原子核电荷或内金属原子核电荷的突变也有抑制作用，可以认为这种“保留率”是一个复杂的产物，不仅是金属富勒烯对（n，γ）反应中反冲能的耐受性，而且是富勒烯分子对反应器中γ剂量的稳定性和在中子辐照后施加于样品的化学过程的每个步骤中的化学产率。观察到的氘代D1169氘代D1 Yb/氘代D1175氘代D1 Yb和氘代D1153氘代D1 Gd/氘代D1161氘代D1 Gd的保留产率比得出结论， ...更多信息 在（n，γ）反应后，M@C_（282）O为了进一步研究放射性衰变过程对金属富勒烯物理化学稳定性的影响，对La@C富勒烯D282富勒烯D2进行了实验，以消除化学处理过程中对化学产率的修正，得到反应堆辐照下的总保留产率为20%.结果表明，在普通溶剂萃取和高效液相色谱分离的化学过程中稳定的金属富勒烯，只要在同一个碳笼中，子核的氧化态与母核的氧化态保持一致，对笼中金属原子的β衰变和EC衰变过程也是稳定的。但是如果氧化态通过核转变而改变，则似乎形成化学不稳定的金属富勒烯，如在β衰变中所证明的那样，氧化态可能从+2变为+3。然而，通过对イD1146 D1 Gd-イD1146 D1 Eu EC衰变的研究，实验上首次发现了一种特殊的CイD282 D2碳笼的存在，它与+2和+3氧化态的金属原子形成化学稳定的金属富勒烯。少

项目成果

K. Sueki et al.: "Speciticity of Carbon Cageo towards Oxidation States of Metol Atoms in Metdlofullenenes"Chem. Phys. Lett.. 291. 37-43 (1998)

K. Sueki 等人：“Carbon Cageo 对 Metdlofullenenes 中 Metol 原子氧化态的特异性”Chem。

K. Akiyama, K. Sueki, T. Kodama, K. Kikuchi, Y. Takigawa, H. Nakahara, I. Ikemoto, M. Katada: "New fullerenes of a group IV element: Hf metallofullerenes"Chem. Phys. Lett.. 317. 490-496 (2000)

K. Akiyama、K. Sueki、T. Kodama、K. Kikuchi、Y. Takikawa、H. Nakahara、I. Ikemoto、M. Katada：“IV 族元素的新富勒烯：Hf 金属富勒烯”Chem。

K.Sueki et al.: "Stability of Radio-Metallo-Fublerenes against Beta-Decay" J.Radio anal.Nucl.Chem.239. 179-186 (1999)

K.Sueki 等人：“Radio-Metallo-Fublerene 对 Beta-Decay 的稳定性”J.Radio anal.Nucl.Chem.239。

K. Sueki et al.: "Formation of Metallofullemenes with High Group elements"Chem. Phys. Lett.. 300. 140-144 (1999)

K. Sueki 等人：“具有高族元素的金属富勒烯的形成”Chem。

K. Sueki, K. Akiyama, K. Kikuchi, H. Nakahara, K. Tomura: "Stability of Radio-Metallo-Fullerene against Beta-Decay"J. Radioanal. Nucl. Chem.. 239. 179-186 (1999)

K. Sueki、K. Akiyama、K. Kikuchi、H. Nakahara、K. Tomura：“放射性金属富勒烯对抗 Beta 衰变的稳定性”J。