光分解可能な外部リガンドによる光誘発スピン変化: 分子の磁気スイッチングのための新しい原理
Steffen Thies1, Hanno Sell, Christian Schütt
1Otto-Diels-Institut für Organische Chemie, Christian-Albrechts-Universität, Otto-Hahn-Platz 4, D-24098 Kiel, Germany.
Journal of the American Chemical Society
|September 6, 2011
まとめ
研究者は,光を用いて個々の分子で室温の磁気スイッチングを達成しました. この光駆動による協調誘発スピン状態スイッチング (LD-CISSS) は,分子磁力学の新たな可能性を提供します.
科学分野:
- 分子磁気は分子磁気である
- 超分子化学 超分子化学
- フォトケミストリー フォトケミストリー
背景:
- スピン・クロスオーバー材料における磁気バイスタビリティは,典型的には集団的な固体状態現象である.
- 溶液中の分子レベルの磁気スイッチングを達成することは大きな課題です.
研究 の 目的:
- 均質な溶液中の個々の分子の光駆動磁気スイッチングを実証する.
- 分子レベルで光駆動による協調誘発スピン状態スイッチング (LD-CISSS) のメカニズムを調査する.
主な方法:
- 四角平面のプラットフォームとしてNi-porphyrinと,光分解性軸性リガンドとしてアゾピリジンを使用した.
- 紫外線 (365 nm) と可視光 (455 nm) を使って,アゾピリジンのトランスシスイソメリゼーションを誘導し,調整とスピンの状態を変更しました.
- ポルフィリン/アゾピリジン複合体の関連定数を決定し,スイッチング効率に対する置換剤サイズの影響を評価した.
主要な成果:
- 溶液中のNi-ポルフィリン複合体について,二磁性 (低スピン,S=0) とパラ磁性 (高スピン,S=1) 状態の間の可逆的な切り替えが実証されています.
- イソプロピル置換アゾピリジンを用いて室温で20~68%のパラマグネット性ニオンの種の光誘発的,可逆的なスイッチングを達成した.
- アゾピリジンに対するより大きな置換剤は,同位体間の結合定数の違いを高め,スイッチング効率を改善することを示した.
結論:
- 溶液中の個々の分子は,光駆動磁気バイスタビリティを発揮することができる.
- LD-CISSSは,光を用いて分子磁気特性を制御するための新しい経路を提供します.
- このシステムは,新しい分子スイッチやメモリデバイスを開発する可能性を秘めています.
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