在烯衍生物的两个位置异构体中存在弱非对应相互作用:来自PIXEL能量,希尔什菲尔德表面和QTAIM分析的输入
M Judith Percino1, Mani Udayakumar2, Margarita Cerón1
1Instituto de Ciencias, Unidad de Polímeros y Electrónica Orgánica, Benemérita Universidad Autónoma de Puebla, Val3-Ecocampus Valsequillo, Puebla, CP, Mexico.
Frontiers in chemistry
|July 14, 2023
概括
对两个烯酸异构体的结构分析揭示了对晶体包装和分子间相互作用的边缘定位异构体效应. 两种异构体都表现出类似的固态排列和可比的晶格能量,由希什菲尔德表面和能量分析证实.
科学领域:
- 晶体工程和超分子化学
- 有机固态化学 有机固态化学
- 计算化学计算化学
背景情况:
- 了解定位异构对晶体包装和分子间力量的影响,对于设计功能有机材料至关重要.
- 烯二衍生物与二替代剂代表了一类化合物,在材料科学中具有潜在的应用.
研究的目的:
- 为了研究和比较两个定位异构体的晶体结构和分子间相互作用的pyridylphenyl烯酸衍生物.
- 阐明甲基组定位 (meta vs. para) 对固态排列,晶格能量和电子特性的影响.
主要方法:
- 单晶X射线衍射分析被用来确定两个异构体的晶体结构.
- 希什菲尔德表面分析被用来量化各种分子间相互作用对晶体包装的贡献.
- 库伦-伦敦-保利-皮克塞尔 (CLP-PIXEL) 能量分析和分子中原子的量子理论 (QTAIM) 用于能量计算和相互作用强度评估.
- 进行了UV-Vis光谱和时间依赖密度功能理论 (TD-DFT) 计算,以评估电子性质.
主要成果:
- 这两种定位异构体均以每个不对称单位的两个独立分子结晶,分别在单临床 (P21/n) 和三临床 (P-1) 空间组中.
- 希尔什菲尔德表面分析表明,分子间C-H··C(π) 接触占两个异构体晶体包装相互作用的40%以上,贡献相似.
- 发现定位异构体效应是边际的,导致类似的固态结构,可比的格子能量和类似的UV-Vis吸收光谱.
- 能量分析发现了显著的二分体相互作用,QTAIM证实了内部和分子间相互作用的强度.
结论:
- 托利基组的位置 (meta vs. para) 对这些烯酸衍生物的晶体包装,分子间相互作用和电子性质的影响最小.
- 这项研究强调了C-H···C(π) 相互作用在这些化合物的晶体包装中占主导地位.
- 这些发现表明,微妙的结构修改,如定位异构,可能不会显著改变这种类分子的固态行为和特性.
相关概念视频
01:28Structures of Carboxylic Acid Derivatives
2.7K
Structure of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the...
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the...
2.7K
01:19Structure of Amines
2.6K
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’...
2.6K
04:01VSEPR Theory and the Effect of Lone Pairs
42.5K
Effect of Lone Pairs of Electrons on Molecule Geometry
42.5K
02:30Stability of Substituted Cyclohexanes
12.7K
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
12.7K
02:06Newman Projections
17.0K
Different notations are used to represent the three-dimensional structure of molecules on two-dimensional surfaces. One of the most commonly used representations is the dash-wedge formula. The dashed wedges, solid wedges, and the plane lines indicate the groups situated behind the plane, coming out of the plane, and in the plane, respectively.
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
The organic molecules rotate across the single bonds leading to numerous temporary three-dimensional structures of varying energy known as...
17.0K
02:37Structure and Physical Properties of Alkynes
10.8K
Introduction:
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The...
In nature, compounds containing both carbon and hydrogen are known as "hydrocarbons". Aliphatic hydrocarbons are compounds whose molecules contain saturated single bonds (i.e., alkanes) or unsaturated double or triple bonds. Alkenes contain carbon–carbon double bonds and have a structural formula CnH2n. Unsaturated hydrocarbons containing carbon–carbon triple bonds are called "alkynes" and are structurally represented by the formula CnH2n-2.
The...
10.8K