分子電荷メーターによる電荷計画性能の直接実験評価

Roie Yerushalmi¹, Avigdor Scherz, Kim K Baldridge

¹Department of Plant Sciences, The Weizmann Institute of Science, 76100 Rehovot, Israel.

Journal of the American Chemical Society

|May 6, 2004

まとめ

この研究は,金属複合体における電荷移転のための計算方法を検証しています. 自然人口分析 (NPA) は,他の多くの計算スキームとは異なり,電荷密度移転を正確に予測します.

科学分野:

コンピューティング・ケミストリー
物理化学物理化学
スペクトロスコーピーは,スペクトロスコーピーを用います.

背景:

理論化学と計算化学は著しく進歩し,複雑な化学システムのシリコ研究を可能にしました.
複雑な環境における基本的な化学量測定のための実験能力は,理論的な進歩に遅れをとっている.
多くの研究は,独立した実験的検証なしに理論的な予測に依存しており,これは望ましくない.

研究の目的:

原子電荷と断片的電荷密度移転の決定のための一般的な理論的アプローチを実験的に評価する.
高精度な実験データを用いた計算方法の独立した評価を提供すること.
金属複合体における電荷移転を研究するための堅実な計算方法の特定.

主な方法:

ニッケル・バクテリオクロロフィルを分子ポテンチオメーターとして利用し,金属複合体における断片的電荷密度移転を測定した.
理論的な電荷分析方法の評価のために,分子電位計からの実験データを使用した.
自然集団分析 (NPA) と静電ポテンシャル (ESP) のフィットベースの方法による結果の比較.

主要な成果:

自然人口分析 (NPA) は,ドナー・アクセプター協調相互作用におけるチャージ転送の評価において高い強度と精度を示した.
テストされたコンピューティングチャージスキームのほとんどは,研究された化学システムを正確に表現できませんでした.
静電ポテンシャルフィットベースのメソッドは,電子相関の有意な変動を持つシステム,例えばモノ複合体や双重複合体のシステムでは問題であることが示されました.

結論:

NPAは,金属複合体における電荷伝送プロセスを評価するための信頼できる方法である.
電子的相関効果が顕著で,静電的潜在力の方法が信頼できない場合,代替的な計算方法が必要です.
実験的検証は,複雑な化学システムを研究する理論化学と計算化学の進歩に不可欠です.

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