ウラン (II) アレンの複合体として作用するウラン (I) シントン
Mark D Straub1,2, Erik T Ouellette1,2, Michael A Boreen1,2
1Department of Chemistry, University of California, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|November 17, 2021
まとめ
この研究は,ウラン複合体の電子構造を明らかにし,それがU (I) シントンとして作用することを示しています. 新しいウラン化合物を形成する 還元剤としてその反応性を詳細に説明しています
科学分野:
- 有機金属化学
- ウラン化学
- アクチニド化学
背景:
- アミダート基のウラン複合体は 独特の電子特性を有する.
- ウランの還元状態と反応性を理解することは,触媒と材料科学にとって極めて重要です.
研究 の 目的:
- 新しいアニオン系ウラン複合体を合成し,特徴づけること.
- これらの複合体の電子構造と再酸化行動を調査する.
- 様々な基板との減少ウラン種の反応性を調査する.
主な方法:
- ウランとトリウムアミダート複合体の合成
- KC8を用いた2電子還元
- EPR (スペクトロスコーピカル・キャラテリゼーション)
- 磁気感受性の測定
- 計算型研究 (DFT,CASSCF)
- ヨウ素,サイクロヘプタトリエン,サイクロオクタテトレーンによる反応性試験
主要な成果:
- アニオン bis ((アレン) 複合体 [K[2.2.2]cryptand][U ((TDA) 2) (3) の形成は,U ((II)) センターと単調化されたアレンによる.
- 複合体3はU(I) シントンとして作用し,I2をU(III) -U(III) 種に,CHTをU(IV) 複合体に還元する.
- COTとの反応はU(III) とU(COT) 2を生じ,複合体2はU(IV) -U(IV) の逆サンドイッチ複合体を生成する.
- Th (TDA) 4 (4) を減量すると,K (2.2.2) クリプトン[Th (TDA) 3 (THF) ] (5) を減量したアレンで得られます.
結論:
- 複合体3の電子構造は,単調化されたアレンを持つU (II) センターであり,U (I) シントンとして振る舞う.
- 反応性研究により,U (I) 種の多用途の還元能力が示されている.
- トリウム複合体5は,異なる酸化還元作用を示す,Th (IV) に結合した二酸化還元素を特徴とする.
さらに関連する動画
07:20Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents
Published on: May 28, 2014
14.1K
12:27Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
Published on: September 8, 2013
11.0K
関連する概念動画
03:20Nuclear Transmutation
19.3K
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed...
19.3K
02:34Structural Isomerism
20.1K
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...
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...
20.1K
02:38Electrophilic Addition to Alkynes: Halogenation
8.9K
Introduction
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
8.9K
01:19Complexation Equilibria: The Chelate Effect
726
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...
726
02:42Valence Bond Theory
9.8K
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...
9.8K
01:20Diazonium Group Substitution with Halogens and Cyanide: Sandmeyer and Schiemann Reactions
2.0K
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...
2.0K