離子電荷転移複合体における単結合 (C(60) (((-)) ((2) ダイマーの可逆的形成:Cp*(2) Cr.C(60) (((C(6) H(4) Cl(2)) (((2). (C ((60) (((-)) ((2))
Dmitri V Konarev1, Salavat S Khasanov, Akihiro Otsuka
1Division of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan. konarev@icp.ac.ru
Journal of the American Chemical Society
|July 18, 2002
まとめ
C60フルレレンとデカメチルクロモセンの新しいイオン複合体は,低温で可逆的二分化を示す. この構造の変化は磁気特性に影響を及ぼし,X線 difraktion 研究によって確認されています.
科学分野:
- 超分子化学 超分子化学
- マテリアルサイエンス 材料科学
- 固体物理 固体物理学
背景:
- フルレレン,特にC60は,材料科学における汎用的な構成要素である.
- フルレンを含むイオン複合体は,ユニークな電子的および構造的特性を提供します.
- デカメチルクロモゼン (Decamethylchromocene,Cp*2Cr) は,電荷移転複合体を形成する可能性がある有機金属化合物として知られています.
研究 の 目的:
- デカメチルクロモゼンによるC60の新しいイオン複合体を合成し,特徴づけること.
- 複合体の構造および磁気特性を,特に低温で調査する.
- フルレンの二分化に関連した相変化を理解するために.
主な方法:
- 低温構造を決定するために100 Kの単結晶X線 difraktion.
- 磁気モメントの変化を監視するための磁気感受性測定.
- 電子パラマグネティック共振 (EPR) スペクトロスコピーは,パラマグネティックな種を検出します.
主要な成果:
- 新しいイオン複合体の形成:デカメチルクロモセン-C60 (ディクロロベンゼン) 2.
- 室温でのモノメアC60と低温での単結合 (C60-) 2ダイマー形成の観測.
- X線 difraktionにより,ダイマーにおけるC−C結合の長さは1.597~7 Åであり,フルレン間の距離は9.28 Åであったことが明らかになった.
- 200~220Kの間には,ユニット細胞のパラメータの変化によって特徴づけられた可逆的な相変遷が発生した.
- 磁気モメントは4.20μBから3.88μBに低下し,Cp*2Cr+からのEPR信号が現れた.
結論:
- 合成された複合体は,温度に依存するフルレン二分化を示す.
- 観測された相変化は, (C60-) 2ジメルの可逆的形成に起因する.
- 構造的および磁性的な変化は,可逆的二分化および関連する電子的再編成の証拠を提供します.
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