一个独立的状态:合理化高Z晶体结构的石基酸乙
Ronnie Ragbirsingh1, Michael J Hall1, Michael R Probert1
1Chemistry, School of Natural and Environmental Sciences, Newcastle University, Bedson Building, Newcastle upon Tyne NE1 7RU, U.K.
Crystal growth & design
|February 12, 2024
概括
具有多个独立分子的高Z'晶体结构并不常见. 这项研究揭示了石基酸,特别是甲基石基酸 (Z'=12),为控制复杂有机晶体形成的因素提供了新的见解.
科学领域:
- 晶体学 晶体学是指结晶学.
- 有机化学 有机化学
- 材料科学 材料科学 材料科学
背景情况:
- 高Z' (不对称单位中对称性独立分子的数量) 晶体结构很罕见,难以预测.
- 这些结构被认为是由于平衡的分子间力量而形成的.
- 研究新的高Z'实例对于推进晶体结构预测至关重要.
研究的目的:
- 为了研究石基酸的X射线晶体结构.
- 确定导致这些有机化合物中高Z'值的因素.
- 为科学界提供高Z'晶体结构的新例子.
主要方法:
- 采用X射线晶体学来确定晶体结构.
- 对不对称单元的分子组成和排列的分析.
- 晶体结构的比较在一系列的石基酸.
主要成果:
- 发现几种石基酸乙烯表现出高的Z'值.
- 甲基石基酸盐的Z'值极高,为12.
- 鉴定出来的因素包括同质性,环刚性,结合和合体.
结论:
- 这项研究提出了新的高Z'晶体结构的石基酸.
- 甲基石基酸的Z'=12归因于分子和分子间因素的组合.
- 在这个系列中,基团的固体质量和结动机影响了高Z'的形成.
相关概念视频
E1 Reaction: Stereochemistry and Regiochemistry
9.5K
One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.
9.5K
Esters to β-Ketoesters: Claisen Condensation Mechanism
3.6K
Regular Claisen condensation involves the synthesis of β-ketoesters by combining identical ester molecules bearing two α hydrogens in the presence of an alkoxide base. The reaction commences with the deprotonation of the acidic α hydrogen by the base to form a resonance stabilized ester enolate. This nucleophilic ion then attacks the carbonyl center of another ester molecule to generate a tetrahedral alkoxide intermediate. Next, the expulsion of the alkoxide group from the...
3.6K
Carboxylic Acids to Esters: Acid-Catalyzed (Fischer) Esterification Mechanism
7.9K
Carboxylic acids react with alcohols to yield esters via an acid-catalyzed condensation reaction called Fischer esterification. This is a nucleophilic acyl substitution reaction that proceeds via a tetrahedral intermediate, where a water molecule is eliminated as the leaving group.
7.9K
E2 Reaction: Stereochemistry and Regiochemistry
11.5K
Elimination reactions of alkyl halides can yield one or more alkenes depending on the specific regiochemical and stereochemical considerations. While the regiochemistry of the reaction governs the location of the double bond in the product, the stereochemical requirements often influence the geometry.
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...
11.5K
Acid Halides to Esters: Alcoholysis
2.8K
Alcoholysis is a nucleophilic acyl substitution reaction in which an alcohol functions as a nucleophile. Acid halides react with alcohol to produce esters. The mechanism proceeds in three steps:
2.8K
Sharpless Epoxidation
4.0K
The conversion of allylic alcohols into epoxides using the chiral catalyst was discovered by K. Barry Sharpless and is known as Sharpless epoxidation. The use of a chiral catalyst enables the formation of one enantiomer of the product in excess. This chiral catalyst is mainly a chiral complex of titanium tetraisopropoxide and tartrate ester (specific stereoisomer). The stereoisomer used in the chiral catalyst dictates the formation of the enantiomer of the product. In other words, the use of...
4.0K


