軸に結合したMn (V) -オクソ複合体の酸素原子移転反応性:強化された電愛性および核愛性経路の証拠
Heather M Neu1, Tzuhsiung Yang, Regina A Baglia
1Department of Chemistry, The Johns Hopkins University , Baltimore, Maryland 21218, United States.
Journal of the American Chemical Society
|September 20, 2014
まとめ
アニオンドナーは,酸素原子移転反応におけるマンガン ((V) -オクソコルロラジン複合体の反応性を劇的に影響する. 軸性リンガンドの選択は反応性傾向とメカニズム的経路を決定し,高価マンガンの触媒に関する新しい洞察を提供します.
科学分野:
- 協調化化学について
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
背景:
- マンガネスコルロラジン複合体は強力な酸化物質です.
- 酸素原子移転 (OAT) 反応性は酸化触媒において極めて重要です.
- 軸性リガンド効果を理解することは,チューニング反応性の鍵です.
研究 の 目的:
- マンガン ((V) -オクソコルロラジン複合体のOAT反応性に対するアニオン軸性ドナーの影響を調査する.
- これらのOAT反応を制御するメカニズム的経路を解明する.
- 実験的観測と理論的計算を相関させる.
主な方法:
- 6座標アニオンマンガン (((V) -オクソコルロラジン複合体の合成と特徴付け.
- Mn-Oの振動モードを研究するための共振ラーマン光譜法.
- チオエーテル酸化反応の製品分析.
- 二次速度定数を用いた動力学的研究.
- 密度関数理論 (DFT) による計算.
- 代替チオエーテル基板を使ったハメット研究.
主要な成果:
- アニオンドナー (F-, N3-, OCN-) は,Mn-Oの振動周波数のダウンシフトを引き起こします.
- 硫酸化に対する反応性傾向は以下の5座標で確認された: ≈チオシアネート ≈ニートレート <シアネート <アジド <フッ化物 ≪シアン化物.
- 異常な"V形"ハメットプロットは,基板と軸性リガンドに基づく酸化機構 (電子性対核性) のスイッチを示しています.
- 一電子酸化複合体と比較すると,単純な電友性メカニズムが示される.
結論:
- 軸性リンガンドは,OATの反応性とマンガネス (((V) -オクソコルロラジン複合体のメカニズムを大幅に制御します.
- 電子性および核性酸化経路の間で切り替える能力は,重要な発見です.
- この研究は,高価マンガンの触媒と酸化剤の設計に関する基本的な洞察を提供します.
さらに関連する動画
11:04Ion Mobility-Mass Spectrometry Techniques for Determining the Structure and Mechanisms of Metal Ion Recognition and Redox Activity of Metal Binding Oligopeptides
Published on: September 7, 2019
8.3K
09:02Manganese Oxide Nanoparticle Synthesis by Thermal Decomposition of ManganeseII Acetylacetonate
Published on: June 18, 2020
12.9K
関連する概念動画
01:21Radical Oxidation of Allylic and Benzylic Alcohols
2.2K
Activated manganese(IV) oxide can selectively oxidize allylic and benzylic alcohols via a radical intermediate mechanism. Primary allylic alcohols are oxidized to aldehydes, while secondary allylic alcohols yield ketones. The redox reaction of potassium permanganate with an Mn(II) salt such as manganese sulfate (under either alkaline or acidic conditions), followed by thorough drying, yields the oxidizing agent: activated MnO2. While MnO2 is insoluble in the solvents used for the reaction, the...
2.2K
02:42Valence Bond Theory
8.8K
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...
8.8K
02:51Metal-Ligand Bonds
19.2K
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...
19.2K
03:02Colors and Magnetism
12.0K
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...
12.0K
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
4.9K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
4.9K
03:11Oxidation-Reduction Reactions
58.5K
Oxidation–Reduction Reactions
58.5K