![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
二核鉄複合体における異常な二酸化窒素結合と電子貯蔵
Dieter Sorsche1, Matthias E Miehlich2, Keith Searles1,3
1Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
Journal of the American Chemical Society
|April 3, 2020
まとめ
この研究では,希少な二核鉄複合体とブリッジされた二酸化窒素リガンドが報告されています. 研究者は新しい鉄-二酸化窒素複合体を特徴付け,ユニークな協調幾何学と電子構造を明らかにした.
科学分野:
- 無機化学
- 有機金属化学
- 協調化学
背景:
- 二酸化窒素 (N2) コンプレックスは,触媒と窒素固定の研究において極めて重要です.
- 二核鉄二酸化窒素種の調整と電子構造を理解することは,新しい触媒システムの開発の鍵です.
- 以前の研究は単核鉄二酸化窒素複合体に焦点を当てており,二核システムはあまり研究されていない.
研究 の 目的:
- 橋渡しダイナトロゲンリガンドを備えた新しい二核鉄複合体を合成し,特徴づけること.
- この独特の鉄二酸化窒素化合物の 構造的,電子的,磁性特性を調査する.
- 様々な還元条件下におけるこれらの複合体の反応性と安定性を調べる.
主な方法:
- KC8還元を用いた二核鉄複合体の合成
- シングルクリスタルX線微分法による特徴化.
- 磁気感受性測定 (溶液と固体状態)
- 57Fe モースバウアー光譜法
- 密度関数理論 (DFT) の計算
主要な成果:
- 非線形にブリッジされた二核鉄核を報告した.
- 異常な調整幾何学を持つ4つの新しい鉄-二酸化窒素複合体 (2-5) を合成し,特徴づけました.
- cis-divacant octahedral coordinationとcation-pi相互作用による歪んだFeN2Feコアが観察されました.
- 複合体2は熱的に不安定で,N2の損失と不均衡をもたらすことが示された.
結論:
- 前例のない二核鉄二窒素複合体を 合成し特徴づけました
- 独特の調整環境はFeN2Feコアの電子構造と安定性に大きく影響します.
- これらの発見は,鉄-二酸化窒素の相互作用と潜在的な触媒の応用に関する新しい洞察を提供します.
関連する概念動画
03:02Colors and Magnetism
13.6K
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...
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...
13.6K
02:51Metal-Ligand Bonds
23.5K
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...
23.5K
02:42Valence Bond Theory
10.8K
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...
10.8K
01:19Complexation Equilibria: The Chelate Effect
1.0K
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
1.0K
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
720
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
720
01:22EDTA: Chemistry and Properties
3.1K
Polydentate ligands are most widely used in complexometric titrations because they form more stable complexes with the metal ions than mono- or bidentate ligands due to the chelate effect. Examples of polydentate ligands are ethylenediaminetetraacetic acid (EDTA), crown ethers, and cryptands. The most important feature of optimal polydentate ligands is the ability to form 1:1 complexes in a single-step process. Amino carboxylic acid derivatives are frequently used as complexing agents. EDTA is...
3.1K