超分子組成のU (IV) クラスターと超原子は,従来とは異なる反作用がある
Ian Colliard1, Gregory Morrison2, Hans-Conrad Zur Loye2
1Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, United States.
Journal of the American Chemical Society
|April 23, 2020
まとめ
研究者らは酸度と反作用を制御することで,新しいウラン基超原子 (U84とU70) を生み出した. これらの超原子は 独自の磁気特性を有する 多様な超網状に 自己組み立てられ 材料科学の新たな道を切り開きます
科学分野:
- 材料科学
- 超分子化学
- ナノテクノロジー
背景:
- スーパアトムは 秩序ある格子の中で 階層的な組み立てを通して 発現する性質を示します
- これまでの研究では 量子ドット,pブロッククラスター,そして 超原子としてのフルレンに 焦点を当てていました
- 新しい超原子構造の制御された組み立てを理解することは 先進的な材料にとって極めて重要です
研究 の 目的:
- 超原子としてウラン酸化硫酸クラスターアニオンの新しい家族を導入します.
- 水中のウラン超原子の階層構造を調べるため
- 超原子の形成と組成に 酸性と反作用の影響を調べる
主な方法:
- ウランオキシスルファートクラスターアニオンの合成
- 水溶液で制御された自己組み立てにより,酸性や対酸性 (ランタニドや移行金属) が変化する.
- X線散射と磁気測定を用いた超原子構造と超格子構造の特徴化.
主要な成果:
- ランタニドの大きさに基づく体中心の立方体フレームワークまたは空洞のスーパークラスター (U84超原子) に組み合わされるヘクサマー (U6) オキシクラスターの形成.
- U84の超原子は,様々な超網 (立方体-最も近いパック,体中心の立方体,相互浸透ネットワーク) に自己組み立てます.
- 二価移行金属を用いたU6およびU単体から車輪状のU70クラスターを合成し,有機介質で異なる超分子組成を形成する.
結論:
- 酸性と対カチオンの選択は,ウラン超原子の階層的組成を制御するための重要なパラメータです.
- 発見されたウランの超原子 (U84とU70) は,秩序ある超格子に多様な自己組み立てを示している.
- これらのウラン基の超網状は,2Kまでペアリングされていない5f2電子で興味深い磁気特性を示しています.
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