铜(II) - 寡甘氨酸系统中复合物的结构多样性很大:通过对电子偏磁共振光谱的二维模拟来研究微分和协调模式
Nóra Veronika Nagy1, Terézia Szabó-Plánka, Antal Rockenbauer
1Department of Physical Chemistry, University of Szeged, P.O. Box 105, H-6701 Szeged, Hungary.
Journal of the American Chemical Society
|April 24, 2003
概括
这项研究使用了EPR光谱和矩阵排名分析来识别14种铜 (II) 复合物与糖氨酸. 强大的铜键和合的酸盐环影响了复杂的稳定性和结构.
科学领域:
- 协调化学 协调化学
- 生物有机化学 生物有机化学
- 频谱学是一种光谱学.
背景情况:
- 铜 (II) 复合物与在生物系统和催化过程中至关重要.
- 了解这些复合物的物种化和协调模式是必不可少的.
- 之前的研究已经探索了铜-甘氨酸相互作用,但对各种甘氨酸长度和质子化状态的全面分析缺乏.
研究的目的:
- 识别和表征铜 (II) 复合物,这些复合物与甘油,甘油三和甘油四形成.
- 确定这些复合体的形成常数和磁性参数.
- 阐明已识别的铜II-甘氨酸物种的协调模式和结构特征.
主要方法:
- 电子偏磁共振 (EPR) 谱学被用来研究铜的平衡系统 (II) 与不同度的滴甘,三甘和四甘.
- 使用矩阵等级分析来确定独立的EPR活性物种的数量.
- 两维数据评估促进了确定金属复合物的形成常数和磁性参数的计算.
主要成果:
- 对于每个连接体系统,确定了14个独立的金属复合体,包括微物种.
- 确定了一些特定的偏磁性物种,如Cu(2+) (水复合物),[CuLH](2+),[CuL](+),[CuLH(-1) ],[CuLH(-2) ],[CuL(2) H(2) ],2+),[CuL(2) H]+),[CuL(2) ],[CuL(2) H(-1) ]-),[CuL(2) H(-2) ]-),[CuL(2-),和[CuLH(-3) ]2-).
- 观察到铜 (II) 和捐赠体之间的强烈平面内西格玛键,特别是当联体形成多个酸盐环时. 结合的酸盐环结构在bis复合体中得到了青,观察到不同的联结体质子状态.
结论:
- 该研究成功地描述了广泛的铜II-甘氨酸复合物,详细介绍了它们的形成和磁性特性.
- 铜键的强度和结合酸盐环的形成是决定这些复合物的稳定性和结构的关键因素.
- 这些发现为铜的协调化学提供了详细的见解 (II) 与短的甘氨酸,这对理解金属相互作用很重要.
更多相关视频
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
06:31Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase
Published on: March 19, 2020
相关概念视频
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...
02:52Stereoisomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
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...
03:02Colors and Magnetism
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 eye.
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 eye.
01:13¹H NMR: Complex Splitting
A proton M that is coupled to a proton X results in doublet signals for M. However, NMR-active nuclei can be simultaneously coupled to more than one nonequivalent nucleus. When M is coupled to a second proton A, such as in styrene oxide, each peak in the doublet is split into another doublet.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.