薄弱稳定的初级酸及其二化二聚体.
Aleksandrs Prokofjevs1, Jeff W Kampf, Andrey Solovyev
1Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States.
Journal of the American Chemical Society
|October 4, 2013
概括
研究人员从化物桥梁盐中产生可观测的酸. 根据使用的易斯基,可以形成初级酸或高度反应的二二元体,从而揭示了化学的新见解.
科学领域:
- 有机化学 有机化学
- 碳化物化学 碳化物化学
- 超分子化学 超分子化学
背景情况:
- 酸通常是高度反应和短暂的物种.
- 离子的稳定对于理解它们的反应性和合成效用至关重要.
- 化物桥梁化合物为产生和分离新离子提供了潜在的途径.
研究的目的:
- 通过从单离子化物桥梁盐中提取化物来研究酸的生成.
- 探索不同易斯基 (L) 对产生的离子稳定性和结构的影响.
- 为了描述可观测的初级酸和形成的二酸二次体.
主要方法:
- 用各种易斯基 (L) 合成单离子化物桥接盐[H(H2B-L) 2+ .
- 使用合适的试剂进行化物抽象反应.
- 产生的物种的光谱表征 (例如,NMR).
- 结晶学分析用于结构确定.
主要成果:
- 当 L = iPr2NEt.时,一个可观测的初级阳离子被成功生成.
- 使用替代的易斯基,如L = Me3N,Me2NPr和N-异环碳酸,形成了高度反应的二二元.
- 易斯基的选择决定了化物抽象的结果,导致不同的离子物种.
结论:
- 该研究表明,通过受控的化物抽象生成可观测的酸的可行性.
- 易斯基的性质是确定离子的稳定性和聚合状态的关键因素.
- 这项工作为合成和研究含的新型反应中间体提供了基础.
相关概念视频
Complexation Equilibria: Factors Influencing Stability of Complexes
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...
Valence 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...
Ionic Bonding and Electron Transfer
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions.
Complexation Equilibria: The Chelate Effect
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...
Structural 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...
Metal-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...


