状 π-结合双螺旋氨基基基与三重基态
Haoxin Guo1, Joshua B Lovell2, Chan Shu1
1Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States.
Journal of the American Chemical Society
|March 19, 2024
概括
我们从bis[5]diazahelicene前体合成了一种高度持久的性高旋转基. 这种稳定的二基体表现出三重基态和显著的持久性,为新分子材料铺平了道路.
科学领域:
- 有机化学
- 材料科学
- 光谱学
背景情况:
- 高旋转二根对于分子磁力和旋转电子学至关重要.
- 奇拉螺旋体具有独特的结构和电子特性.
- 开发持久高旋转的有机分子仍然是一个重大挑战.
研究的目的:
- 为了合成和描述一种新奇的性高旋转激素.
- 调查激素的持久性和电子性质.
- 在材料科学中探索奇拉二根的潜在应用.
主要方法:
- 合成奇拉 bis [5] 甲前体.
- 电子磁共振 (EPR) 光谱和SQUID磁测用于表征.
- 基拉尔超临界流体染色法用于反体丰富.
- 密度函数理论 (DFT) 计算用于理论见解.
主要成果:
- 一种中性高旋转二基与三基状态 (ΔEST ≈ 0.4 kcal mol−1) 已成功合成.
- 这种激素具有异常的持久性,半衰期高达6天,显著超过已知的氨基基基.
- 具有高反体过量 (EE ≥94%) 的富前体得到.
- 对于四胺前体 (ΔG‡ = 43 ± 0. 01 kcal mol−1) 和双基 (ΔG‡ ≥ 26 kcal mol−1) 均确定了高的种族化障碍.
结论:
- 合成的性激素表现出前所未有的稳定性和三重基态.
- 其独特的电子结构,具有有效的3电子C-N键,有助于其高持久性.
- 这项研究突出显示了化素作为具有定制磁性质的先进有机材料的构建块的潜力.
相关概念视频
01:07Radicals: Electronic Structure and Geometry
4.0K
This lesson delves into the geometry of a radical, which is influenced by the electronic structure of the molecule. The principle is similar to that of a lone pair, where the unpaired electron influences the geometry at the radical center.
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
4.0K
02:30Chirality at Nitrogen, Phosphorus, and Sulfur
5.7K
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...
5.7K
01:33Radical Halogenation: Stereochemistry
3.7K
Stereochemistry is the study of the different spatial arrangements of atoms in a given molecule. The stereochemistry of radical halogenations can be understood from three different situations:
Halogenation to form a new chiral center:
Halogenation to form a new chiral center:
3.7K
01:19Structure of Amines
2.5K
The hybridized nitrogen atom in amines possesses a lone pair of electrons and is bound to three substituents with a bond angle of around 108°, which is less than the tetrahedral angle of 109.5°. However, the C–N–H bond angle is slightly larger at 112°, with a carbon–nitrogen bond length of 147 pm. This carbon–nitrogen bond length of of amines is longer than the carbon–oxygen bond of alcohols (143 pm) but shorter than alkanes’...
2.5K
02:25Chirality
24.2K
Chirality is a term that describes the lack of mirror symmetry in an object. In other words, chiral objects cannot be superposed on their mirror images. For example, our feet are chiral, as the mirror image of the left foot, the right foot, cannot be superposed on the left foot.
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
Chiral objects exhibit a sense of handedness when they interact with another chiral object. For example, our left foot can only fit in the left shoe and not in the right shoe. Achiral objects — objects that have...
24.2K
02:25Molecules with Multiple Chiral Centers
11.7K
Molecules that possess multiple chiral centers can afford a large number of stereoisomers. For instance, while some molecules like 2-butanol have one chiral center, defined as a tetrahedral carbon atom with four different substituents attached, several molecules like butane-2,3-diol have multiple chiral centers. A simple formula to predict the number of stereoisomers possible for a molecule with n chiral centers is 2n. However, there can be a lower number where some of the stereoisomers are...
11.7K