两种不同类型的炭化物键之间的能量差异驱动双核 (二氨基碳素) PdII 复合物的区域化
Alexander S Mikherdov1, Mikhail A Kinzhalov1, Alexander S Novikov1
1Saint Petersburg State University , 7/9 Universitetskaya Nab., Saint Petersburg, 199034, Russian Federation.
Journal of the American Chemical Society
|October 5, 2016
概括
这项研究合成了来自和衍生物的双核二碳复合物. 这些复合物的区域化学和稳定性由反应条件和分子内素键控制.
科学领域:
- 有机金属化学
- 超分子化学
- 计算化学
背景情况:
- -NHC复合物在催化和材料科学中至关重要.
- 了解区域异构体复合物的形成和稳定性的因素对于它们的应用至关重要.
- 达米诺碳联体具有独特的协调特性.
研究的目的:
- 合成和表征新的双核二碳复合物.
- 研究与1,3-thiazol-和1,3,4-thiadiazol-2-amines的区域异构复合物的形成.
- 使用实验和计算方法阐明控制区域选择性和热力学稳定性的因素.
主要方法:
- 合成cis-[PdCl2(CNXyl) 2复合物.
- 在中与各种1,3-thiazol-和1,3,4-thiadiazol-2-amines发生反应.
- 使用元素分析,HRESI+-MS,FTIR和1D/2D核磁共振光谱进行表征.
- 通过单晶X射线衍射进行结构阐明.
- 密度函数理论 (DFT) 的计算和分子中的原子 (AIM) 的拓分析.
主要成果:
- 形成两个区域同位素双核二碳化合物.
- 区域异构比取决于醇胺的反应条件,产生动力学 (KRs) 和热力学 (TRs) 控制的区域异构体.
- 在CHCl3溶液中观察到可逆异构.
- DFT和AIM分析显示了分子内素键 (KRs中的S··Cl,TRs中的S··N) 决定了相对的区域异构体稳定性.
- 对实验值和计算值进行了量化.
- 1,3,4-thiadiazol-2-amine衍生物形成了几乎相同数量的区域异构体,能量差异很小.
结论:
- 这项研究成功合成并描述了新型的-NHC复合物.
- 在确定这些复合物的区域选择性和稳定性方面,分子内素结合起着至关重要的作用.
- 可以调整反应条件以有利于动力学或热力学控制的产品.
- 计算方法为控制复杂的形成和稳定性的电子和结构因素提供了宝贵的见解.
相关概念视频
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
9.9K
The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.
9.9K
Structural Isomerism
22.4K
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...
22.4K
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
3.6K
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.
3.6K
Stereoisomerism
14.4K
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...
14.4K
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
6.3K
Diels–Alder reactions between cyclic dienes locked in an s-cis configuration and dienophiles yield bridged bicyclic products.
6.3K
Valence Bond Theory
11.5K
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...
11.5K


