関連する実験動画
Updated: Jun 16, 2026
06:31
Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase
Published on: March 19, 2020
還元されたビス・アミノ・ピリジン・コバルト・ダイナトロゲン複合体の合成と分子および電子構造:リガンド対金属還元
Amanda C Bowman1, Carsten Milsmann, Crisita Carmen Hojilla Atienza
1Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
Journal of the American Chemical Society
|January 21, 2010
まとめ
この研究は,ナトリウムアマルガム還元による中性コバルト二酸化窒素複合体の合成を詳細に説明しています. これらの複合体は,ビス・イミノ・ピリジン・リガンドを備えたもので,コバルト・イミノ・ピリジン酸化状態と二重基底状態を示し,さらに減少するとコバルト二酸化窒素アニオンが生じる.
科学分野:
- 有機金属化学 有機金属化学
- 協調化化学について
- 無機合成の無機合成とは
背景:
- ビス・イミノ・ピリジン・リガンドは,基礎金属化学における多用途の支架である.
- 窒素リガンドを含むコバルト複合物は,触媒および電子アプリケーションに興味があります.
- コバルト-窒素系における酸化還元過程を理解することは,反応性にとって極めて重要です.
研究 の 目的:
- アリル置換ビス (imino) ピリジンのリガンドを用いて中性コバルト二酸化窒素複合体を合成し,特徴づけること.
- これらの新しいコバルト複合体の電子構造と酸化状態を調査する.
- コバルト二酸化窒素種の連続的還元とその電子特性を調査する.
主な方法:
- コバルト二ハリド複合体とビス・イミノ・ピリジンリガンドの合成.
- 窒素大気下でのナトリウムアマルガムの還元により,コバルト二酸化窒素複合体を形成する.
- 磁気感受性測定,X線 difraktion,EPRスペクトル検査,DFT計算などを行いました.
主要な成果:
- 中性コバルト二酸化窒素複合体 ((Ar) PDI) CoN(2) と ((iPr) BPDI) CoN(2) が成功して合成されました.
- 磁気および結晶学的データは,二重基底状態とCo ((I)) 酸化状態を確認しており,これは1電子のケラート還元と一致しています.
- EPRスペクトロスコーピーは,ビス・イミノ・ピリジン基単体占有分子軌道 (SOMO) を示し,さらに減少するとコバルト二酸化窒素アニオンが得られます.
結論:
- ビス・イミノ・ピリジン・コバルト・ダイナトロゲン化合物の連続した1電子減少は,ケラート中心の電子蓄積を持つCoI) センターにつながります.
- DFT計算は,実験的なNNのストレッチ周波数を正確に再現し,計算によるアプローチを検証します.
- この研究は,還元コバルト二酸化窒素複合体の電子構造と,金属の酸化還元反応に対するリガンド設計の影響についての洞察を提供します.
さらに関連する動画
関連する概念動画
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
02:51Metal-Ligand Bonds
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
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...
03:02Colors and Magnetism
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
02:57Coordination Number and Geometry
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
02:54Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...