(3h) J ((((15) N- (((31) P) スピン・スピン結合定数は,N[結合]H....O[結合]Pの水素結合の間の N[結合]H....O[結合]Pの間の,スピン・スピンの結合定数である
Janet E Del Bene1, S Ajith Perera, Rodney J Bartlett
1Department of Chemistry, Youngstown State University, Youngstown, Ohio 44555, USA. fr042008@ysub.ysu.edu
Journal of the American Chemical Society
|May 30, 2002
まとめ
運動方程式結合クラスターの計算では,水素結合の間の三重結合の窒素-15からリン-31の結合定数は,線形配列では測定可能であり,距離に依存しており,構造的決定が可能であることを示しています.
科学分野:
- コンピューティング・ケミストリー
- 量子化学とは,量子化学である.
- スペクトル顕微鏡検査です.
背景:
- 核磁共振 (NMR) スペクトロスコピーは,分子構造と結合に関する貴重な洞察を提供します.
- 水素結合の間の3結合 (15) N-(31) P結合定数 ((3h) J(N[結合]P)) は,分子幾何学の敏感な探査機である.
- これらの結合を理解すると,水素結合系における距離を測定するのに役立ちます.
研究 の 目的:
- N-H...O-P水素結合の間の三結合 (15) N-(31) P結合定数の大きさと振る舞いを調査する.
- これらの結合定数に対する分子幾何学の影響 (線形対非線形) を探求する.
- 水素結合複合体におけるN-PとN-Oの距離を決定するために (3h) J (((N[bond]P) を使用する可能性を評価する.
主な方法:
- 運動方程式結合クラスターシングルおよびダブル (EOM-CCSD) 計算が採用されました.
- 計算は,N-H...O-P水素結合を備えたモデルのカチオンおよびアニオン複合体で行われました.
- P (V) とP (III) の種を含む様々な構造と,線形と非線形の配列が研究されました.
主要な成果:
- 三結合 (15) N-(31) P カップリング定数は,P ((V)) に対して有意であるが,P ((III)) に対して無視できる.
- (3h) J (((N[bond]P) 値は,非線形 (周期的またはオープン) 構造では通常1 Hz未満です.
- より大きな (3h) J ((N[bond]P) 値は,より長い N-P 距離にもかかわらず,線形または近線形で観察されました.
結論:
- フェルミ接触項は,線形複合体において (3h) J (((N[bond]P) に著しく影響し,距離に依存する.
- 実験的に測定された (15) N-(31) P カップリング定数は,線形システムにおける N-P と水素結合 N-O 距離を決定するために利用できます.
- このアプローチは,特定の水素結合分子システムにおける構造の解明のための新しい方法を提供します.
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