ターニティルの回転によってイソメリ化するペンタコーディネートオルガノアンチモニウム化合物
Shiro Matsukawa1, Hideaki Yamamichi, Yohsuke Yamamoto
1Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Japan.
Journal of the American Chemical Society
|February 20, 2009
まとめ
研究者らは,ペンタコーディネートアンチモン化合物 (スティボラン) の2つのステレオアイソマーを合成した. アイソメリゼーションは,三角形リガンドと2つの単歯リガンドを含むターンティルの回転メカニズムによって起こります.
科学分野:
- 有機金属化学 有機金属化学
- ステレオ化学 ステレオ化学
- 協調化化学について
背景:
- ステボランとして知られるペンタコーディネートアンチモンの化合物は,複雑なステレオ化学を現しています.
- 同性化メカニズムの理解は,これらの化合物の反応性を予測し制御するために重要です.
研究 の 目的:
- 新しいペンタコーディネートアンチモニウム化合物を,硬質のトリデントリガンドで合成する.
- 新しく合成されたスティボランにおけるステレオアイソメリゼーションのメカニズムを解明する.
主な方法:
- 新しい硬質のトリデント酸リガンドを用いて,ペンタコーディネートアンチモンの化合物の2つのステレオアイソマーの合成.
- 機械学的研究を用いたアイソメリゼーション経路の分析.
主要な成果:
- ペンタコーディネートアンチモンの化合物の2つのステレオアイソマーの合成が成功しました.
- イソメリゼーションがターンティル回転 (TR) メカニズムを通じて進行することを決定する.
- トライデント系リガンドがトリオとして作用し,2つのモノデント系リガンドが回転中にペアとして作用する識別.
結論:
- ターニティルの回転メカニズムは,これらの新しいスティボランのステレオアイソメリゼーションを制御します.
- 硬いトライデントリガンドは,回転経路の方向づけに重要な役割を果たします.
関連する概念動画
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The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
02:52Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
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02:21Naming Enantiomers
The naming of enantiomers employs the Cahn–Ingold–Prelog rules that involve assigning priorities to different substituent groups at a chiral center. Each enantiomer, being a distinct molecule, is assigned a unique name by the Cahn–Ingold–Prelog (CIP) rules, also called the R–S system. The prefix R- or S- attached to the chiral centers in an enantiomer is dependent on the spatial arrangement of the four substituents on the chiral center. The R–S system essentially comprises three steps:...