用于在水中选择性复合化物或化物离子的氨酸
Todd W Hudnall1, François P Gabbaï
1Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
Journal of the American Chemical Society
|September 12, 2007
概括
两个同位素氨基玻兰在水溶液中选择性地结合化物或化物离子. 这一发现为开发用于特定离子检测的新传感器提供了潜力.
科学领域:
- 超分子化学 超分子化学
- 离子识别 离子识别
- 化学 化学
背景情况:
- 阴离子酸被探索为离子结合.
- 同位体结构可以导致差异性的结合特性.
- 在水性介质中选择性离子检测仍然是一个挑战.
研究的目的:
- 为了研究两个同位素氨基酸的离子结合特性, [p-(Mes2B) C6H4 (((NMe3)) ]+ ([1]+) 和 [o-(Mes2B) C6H4 (((NMe3)) ]+ ([2]+).
- 为了确定这些酸盐在水溶液中对化物和化物离子的选择性.
- 阐明控制它们选择性离子结合的结构和电子因素.
主要方法:
- 合成准和正体异构氨基玻酸盐.
- 使用像NMR光谱学 (隐含) 这样的技术,对离子结合进行实验性调查.
- 计算研究 (例如,DFT) 以了解绑定机制和选择性.
主要成果:
- 酸盐 ([1]+ 和 [2]+) 在有机溶剂中结合化物和化物离子.
- 在水溶液中, [1]+选择性地结合化物 (K = 3.9 x 10^8 M-1).
- [2]+可以选择性地结合化物 (K = 910 M-1).
- 绝缘和电子效应决定了观察到的选择性.
- 结合是可逆的,对其他常见的离子有选择性.
结论:
- 由于Coulombic效应,Para-isomer [1]+对化物具有很高的亲和力.
- 由于中心的易斯酸性增强,正态异构体 [2]+ 结合化物.
- 这些同位素酸盐对水中的特定离子具有显著的选择性,为有针对性的离子传感应用铺平了道路.
更多相关视频
12:05Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia
Published on: October 10, 2013
07:28An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter
Published on: July 13, 2018
相关概念视频
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
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...
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
01:19Complexation 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...
02:42Valence 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...
02:54Coordination Compounds and Nomenclature
In most main group element compounds, the valence electrons of the isolated atoms combine to form chemical bonds that satisfy the octet rule. For instance, the four valence electrons of carbon overlap with electrons from four hydrogen atoms to form CH4. The one valence electron leaves sodium and adds to the seven valence electrons of chlorine to form the ionic formula unit NaCl (Figure 1a). Transition metals do not normally bond in this fashion. They primarily form coordinate covalent bonds, a...