在基于化物的条件下,对在合成二氧化分子中使用的皮佩里迪尼结构指导剂进行研究
Stacey I Zones1, Allen W Burton, Greg S Lee
1Chevron Energy Technology Company, Richmond, California 94802, USA. sizo@chevron.com
Journal of the American Chemical Society
|July 3, 2007
概括
这项研究揭示了离子和有机物如何竞争,以指导特定分子结构的形成. 反应条件会影响低或高框架密度材料的合成.
科学领域:
- 材料科学 材料科学 材料科学
- 无机化学 无机化学 有机化学
- 晶体学 晶体学是指结晶学.
背景情况:
- 了解分子的自我组装对于开发具有定制性质的新材料至关重要.
- 机体和离子在指导这些复杂无机框架的合成中发挥着重要作用.
- 化物离子为分子形成提供了传统氧化物介质的替代合成介质.
研究的目的:
- 研究分子合成中有机物和化离子之间的竞争性相互作用.
- 探索不同的溶液度如何影响结构确定和产品选择性.
- 为了比较 piperidine-derived organocations 在化物和氧化物介质中作为结构指导剂的有效性.
主要方法:
- 合成33种用各种替代剂的piperidine衍生有机物.
- 在合成过程中反应剂度的系统变化.
- 合成材料的表征,以确定主体拓和框架密度.
- 在化物和氧化物介质中合成结果的比较分析.
- 分子建模的应用以阐明结构指导趋势.
主要成果:
- 总共有17种不同的分子宿主拓被确定.
- 反应条件和框架密度之间观察到一种相关性:缩条件有利于低密度结构,而稀释条件产生高密度结构.
- 在化物和氧化物介质之间发现了合成性能的显著差异.
- 分子建模为类似的有机化候选物提供了对选择性趋势的见解.
结论:
- 阳离子的选择 (化物与氧化物) 和溶液度是控制分子合成的关键因素.
- 皮皮里丁衍生的有机物表现出作为结构指导剂的多功能性,导致多样化的框架拓.
- 这些发现提供了对无机有机混合材料的自我组装机制的更深入的理解,指导了未来的新型分子的合理设计.
相关概念视频
01:57Preparation of Diols and Pinacol Rearrangement
Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
03:00Preparation of Epoxides
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
01:23Properties of Organometallic Compounds
Organometallic compounds are compounds that contain a carbon–metal bond. Carbon belongs to an organyl group like alkyl, aryl, allyl, or benzyl groups. The metal can be from Group I or Group II of the periodic table, a transition metal, or a semimetal.
01:16Structure of Conjugated Dienes
Introduction
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
01:29UV–Vis Spectroscopy: Woodward–Fieser Rules
UV–Visible absorption spectra of conjugated dienes arise from the lowest energy π → π* transitions. The light-absorbing part of the molecule is called the chromophore, and the substituents directly attached to the chromophore are called auxochromes. A strong correlation exists between the absorption maxima, λmax, and the structure of a conjugated π system. The Woodward–Fieser rules predict the value of λmax for a given structure by adding the contributions...
01:27Aldol Condensation with β-Diesters: Knoevenagel Condensation
The Knoevenagel condensation is an aldol-type reaction involving the condensation of aldehydes or ketones with active methylene compounds such as β-diesters to produce substituted olefins.