ガス相における7座標ホモレプティック金属カルボニル
Allen M Ricks1, Zach D Reed, Michael A Duncan
1Department of Chemistry University of Georgia, Athens, Georgia 30602, USA.
Journal of the American Chemical Society
|June 16, 2009
まとめ
バナジウムグループの金属カルボニルカチオンは,IR光譜を用いて研究されました. 研究者は,V ((CO) 6 (((+),Nb ((CO) 6 (((+)) とNb ((CO) 7 (((+),Ta ((CO) 7 (((+)) の構造を発見し,理論的な予測とは異なる調整数を決定しました.
科学分野:
- 無機化学 無機化学とは
- 物理化学 物理化学
- スペクトル顕微鏡検査です.
背景:
- 金属カルボニル複合体は,触媒と有機金属化学において極めて重要です.
- 初期の移行金属の協調化学を理解することは,根本的なことです.
- ガス相の研究は,溶媒の影響から自由な固有結合と構造の洞察を提供します.
研究 の 目的:
- バナジウム族の金属カルボニルカチオン (V+,Nb+,Ta+) の座標数と構造を決定する.
- 異なる金属カルボニル種のガス相安定性と形成嗜好を調査する.
- 密度関数理論 (DFT) の理論的予測と実験結果を比較する.
主な方法:
- 分子ビームでレーザー蒸発を用いた金属カルボニルカチオンの製造.
- 飛行時間スペクトロメトリを用いた質量分析とサイズ選択.
- 赤外線 (IR) レーザー光解離スペクトロスコーピーは,カーボニル伸縮周波数を探査します.
- スペクトル予測と構造分析のための密度関数理論 (DFT) 計算.
主要な成果:
- バナジウム (V+) は主に6座標V ((CO) 6 ((+)) を形成し,予測された7座標種ではない.
- ニオビウム (Nb+) は6座標のNb(CO) 6(+) と7座標のNb(CO) 7(+) 複合体の両方を生成した.
- タンタール (Ta+) は,独占的に7座標のTa (((CO) 7 (((+)) 複合体を形成した.
- 実験的なIRスペクトルは,6座標構造と7座標構造の間の明確な違いを示し,DFTの予測と順調に一致しました.
結論:
- COに対するV+,Nb+,Ta+の調整の好みは大きく異なっています.
- V (((CO) 6 (((+) とNb (((CO) 6 (((+) は,わずかに歪んだ八面体構造を採用している.
- Nb (((CO) 7 (((+) と Ta (((CO) 7 (((+) は,C3vの8面形の形状を示しています.
- DFT計算は,これらの金属カルボニルカチオンのIRスペクトルの予測と解釈のための信頼できるツールです.
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