様々な反応経路を持つ末端のNi (III) -イミドである
Elzbieta Kogut1, Heather L Wiencko, Libei Zhang
1Department of Chemistry, Georgetown University, Box 571227, Washington, DC 20057-1227, USA.
Journal of the American Chemical Society
|August 11, 2005
まとめ
ニッケル (((I) ベータ-ディケチミネート複合体は合成され,反応してニッケル-イミド複合体を形成した. これらの複合体は,イミド群の移転と急性特性を含むユニークな結合と反応性を示す.
科学分野:
- 有機金属化学 有機金属化学
- 無機化学 無機化学とは
- 協調化化学について
背景:
- ベータ-ディケチミナートリガンドを含むニッケル複合体は,合成における多用途な構成要素である.
- 13電子ニッケル断片は,新しい金属-リガンド結合を形成するための反応性中間物質です.
研究 の 目的:
- 新しいβ-ディケチミネートNi (I) ルチジンの添加物を合成し,特徴づけること.
- "裸"のニッケル断片のためのシントンとしてこれらの添加物の反応性を探求する.
- ニッケル-イミド複合体の形成と性質を調査する.
主な方法:
- Ni (I) ルチジン添加物の合成.
- N3Adと反応してNi-imido複合体を形成する.
- 構造的決定のためのX線結晶学.
- 電子構造分析のための電子パラマグネティック共振 (EPR) スペクトロスコピー.
主要な成果:
- Ni(I) ルチジン添加物の合成と合成剤としての使用.
- 短いNi-NiとNi-N (imido) の距離を持つ単一の橋渡しイミドの形成.
- 契約されたNi-N-imido) 債券と多重債券の有意な性質を持つNi (III) 終端イミドの分離.
- EPRの研究は,ロムビック環境と,イミド窒素とのハイパーフィンの結合を明らかにしています.
- イミド群移転反応とイミド窒素の急進的性質の実証.
結論:
- ベータ-ディケチミネートNi ((I)) コンプレックスは,反応性ニッケル断片の有効な前駆体である.
- その結果生じるニッケル-イミド複合体は,ユニークな構造および電子特性を示します.
- これらの複合体は,イミド群移転と根基ベースの変換を含む多様な反応性を表しています.
関連する概念動画
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...
01:261° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
Nitrous acid and nitric acids are two types of acids containing nitrogen, among which nitrous acid is weaker than nitric acid. Nitrous acid with a pKa value of 3.37 ionizes in water to give a nitrite ion and the hydronium ion.
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by water loss...
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...
01:371° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
Nitrous acid is a relatively weak and unstable acid prepared in situ by the reaction of sodium nitrite and cold, dilute hydrochloric acid. In an acidic solution, the nitrous acid undergoes protonation when it loses water to form a nitrosonium ion—an electrophile. Nitrous acid reacts with primary amines to give diazonium salts. The reaction is called diazotization of primary amines.
01:26Redox Titration: Other Oxidizing and Reducing Agents
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...