氨酸和乙烯peri-替代的氨酸及其过渡金属复合物:结构和NMR研究
Lutao Zhang1,2, Francesca A Christie1, Anna E Tarcza1
1EaStChem School of Chemistry, University of St. Andrews, St. Andrews KY16 9ST, Fife, U.K.
Inorganic chemistry
|September 18, 2023
概括
新的氨酸乙烯配体具有刚性阿塞纳核,显示强大的穿越空间合. 这些连接体与金属和形成复合体,在它们的结构中揭示金属介导的合路径.
科学领域:
- 有机金属化学 有机金属化学
- 协调化学 协调化学
- 连接体设计 连接体设计
背景情况:
- 开发新的双酸对促进协调化学和催化作用至关重要.
- 基于乙纳的支架提供了刚性,可能会影响捐赠原子之间的电子通信.
- 了解穿越空间合机制,可以深入了解电子结构和结合.
研究的目的:
- 为了合成和表征新的围置换阿塞纳基素乙烯双酸联体 (Acenap (((iPr2P)) ((SeAr)).
- 为了研究这些刚性连接体框架内的电子通信和穿越空间合 (J_PSe).
- 探索这些连接体与晚期d块金属,和的协调行为,并描述由此产生的复合物.
主要方法:
- 氨酸乙烯配体 (L1-L4) 的合成,具有阿塞纳的骨干.
- 使用多核NMR光谱 (包括11B,107Ag,109Ag,195Pt,199Hg) 和单晶X射线衍射进行表征.
- 计算分析包括对选定的复合体进行合变形密度计算.
主要成果:
- 制备了四种基于乙纳的氨酸乙联体 (L1-L4).
- 由于刚性阿塞纳框架,观察了大型透空间4J_PSe合 (452-545 Hz).
- 形成具有易斯酸性基因 (BH3,Mo(CO) 4,Ag+,PdCl2,PtCl2,HgCl2) 的复合体,其中P和Se原子充当桥梁供体.
- 直接观察J_PM和J_SeM合在具有NMR活性金属核的复合体中.
- 溶液NMR,固态结构和计算数据的相关性,表明在复合体中从透空间转向金属介导合的转变.
结论:
- 刚性阿塞纳基架构有效地促进了合成的配体中显著的穿越空间的P-Se合.
- 这些连接体与各种易斯酸形成稳定的复合体,表现出不同的协调模式.
- 金属协调改变了主导的合路径,从通过空间到金属介导,为有机金属复合体中的电子通信提供了宝贵的见解.
相关概念视频
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
5.8K
Chirality is most prevalent in carbon-based tetrahedral compounds, but this important facet of molecular symmetry extends to sp3-hybridized nitrogen, phosphorus and sulfur centers, including trivalent molecules with lone pairs. Here, the lone pair behaves as a functional group in addition to the other three substituents to form an analogous tetrahedral center that can be chiral.
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
A consequence of chirality is the need for enantiomeric resolution. While this is theoretically possible for all...
5.8K
02:52Stereoisomerism
12.0K
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...
12.0K
02:42Valence Bond Theory
8.7K
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...
8.7K
02:51Metal-Ligand Bonds
20.9K
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...
20.9K
02:34Structural Isomerism
19.3K
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...
19.3K
01:16Other Nuclides: 31P, 19F, 15N NMR
410
Many organic, inorganic, and biological molecules contain spin-half nuclei such as nitrogen-15, fluorine-19, and phosphorus-31. As a result, NMR studies of these nuclei have found extensive applications in chemical and biological research.
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
While fluorine-19 and phosphorous-31 have high natural abundances (100%) and positive gyromagnetic ratios, nitrogen-15 has a low natural abundance and a negative gyromagnetic ratio. However, nitrogen-15 is still preferred over nitrogen-14 (which has a...
410