室温のイオン液体のダイナミクス: 2D IR振動エコースペクトル
Steven A Yamada1, Heather E Bailey1, Amr Tamimi1
1Department of Chemistry Stanford University , Stanford, California 94305, United States.
Journal of the American Chemical Society
|January 19, 2017
まとめ
室温のイオン性液体 (RTIL) の動態は2D IRスペクトロスコーピーを用いて研究された. 改変されたカチオン (2-SeCN-Bmim+) は,局所および長距離の液体運動に対する感受性を示す,緩やかな構造的拡散を明らかにした.
科学分野:
- 物理化学
- 材料科学
- スペクトロスコーピー
背景:
- 室温のイオン性液体 (RTIL) は,その用途に不可欠な複雑なダイナミクスを示します.
- RTIL内の分子運動を理解するには,高度なスペクトロスコピーの技術が必要です.
研究 の 目的:
- 1-ブチル-3-メチルミダゾリウムビス (BmimNTf2) の動的振る舞いを振動スペクトロスコーピーを用いて調査する.
- 振動レポーターとして改変されたカチオンを使用して,イオン液体の局所的および集合的ダイナミクスを探査します.
主な方法:
- 2次元赤外線 (2D IR) 振動エコースペクトル
- ポラライゼーション選択ポンププローブ (PSPP) 実験
- 光学ヘテロジン検出光学ケル効果 (OHD-OKE)
主要な成果:
- 修飾されたカチオン (2-SeCN-Bmim+) に対して,長い時間スケールの構造的スペクトル拡散成分 (600 ps) が観察された.
- アニオン (SeCN-) は,きれいな液体の構造的ランダム化時間 (870 ps) よりもはるかに早くスペクトル幅をサンプリングしました.
- 2SeCN-Bmim+の完全な指向ランダム化は ~900 psで発生し,クリーンな液体のランダム化時間と一致しました.
結論:
- 改変したカチオン (2-SeCN-Bmim+) は,スペクトル拡散に影響する局所的なイオン液体の動きに敏感である.
- RTIL構造の完全なランダム化を制御する.
- これらの発見は,イオン性液体の複雑なダイナミクスを洞察します.
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