カリキサレンモノアニオンとダイアニオンの合成,構造,および構成特性
Tracy A Hanna1, Lihua Liu, Alfredo M Angeles-Boza
1Department of Chemistry, Texas Christian University, Box 298860, Fort Worth 76129, USA. t.hanna@tcu.edu
Journal of the American Chemical Society
|June 6, 2003
まとめ
この研究は,アルカリ金属イオンがカリキサレンの構造と形状にどのように影響するかを明らかにしています. 異なる金属イオンは,これらの重要なマクロサイクル化合物の固体構造と溶液の振る舞いを変化させます.
科学分野:
- 超分子化学 超分子化学
- マクロサイクル化学 マクロサイクル化学
- クリスタル・エンジニアリング (Crystal Engineering) とは
背景:
- カリキサレンは,調節可能な性質を持つ多用途のマクロサイクル宿主です.
- カリキサレン構造に対するカウンターイオンの影響を理解することは,新しい材料の設計に不可欠です.
- アルカリ金属イオンは,分子組立に大きく影響する一般的なカウンターイオンです.
研究 の 目的:
- カリックス[n]アレン (n=4, 6, 8) とそのアルカリ金属塩を合成し,特徴づけました.
- これらの塩の固体構造と溶液構成を決定する.
- アルカリ金属イオンのサイズと電荷がカリキサレン組立と動力学に及ぼす影響を調査する.
主な方法:
- 固体構造の決定のためのX線結晶学.
- 溶液の適合性分析のための核磁気共振 (NMR) スペクトロスコーピー.
- 形状のダイナミクスを研究するための可変温度NMR.
主要な成果:
- アルカリ金属イオンは,カリックス[4]アレンの固体結合を決定し,モノマー,ジマー,またはポリマーを形成する.
- カリックス[4]アレンとそのアルカリ金属塩は,溶液中のコンフォームを主に採用しています.
- カリックス [6] アレンは,アルカリ金属イオンとデプロトネーション状態に応じて,異なる反応性と形状の柔軟性を示す.
- カチオン-ピ相互作用は,ほとんどのカリキサレン塩で観察されました.
結論:
- アルカリ金属カチオンの大きさと電荷は,カリキサレン塩の超分子構造を指示する上で重要な役割を果たします.
- カリクセレンの形状と動態は,関連するアルカリ金属イオンによって著しく調節されます.
- これらの発見は,カリキサレンを基にした機能的な超分子システムの合理的な設計に関する洞察を提供します.
さらに関連する動画
09:35Preparation of a Corannulene-functionalized Hexahelicene by Copper(I)-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
Published on: September 18, 2016
11:44Synthesis and Structure Determination of µ-Conotoxin PIIIA Isomers with Different Disulfide Connectivities
Published on: October 2, 2018
関連する概念動画
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:02Chair Conformation of Cyclohexane
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
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...
01:18Aromatic Hydrocarbon Anions: Structural Overview
Neutral hydrocarbons like cyclopentadiene with an odd number of carbon atoms and one intervening CH2 group in the ring are not aromatic. Cyclopentadiene with 4 π electrons does not satisfy the 4n + 2 π electron rule. Additionally, the intervening CH2 group is sp3 hybridized and lacks a vacant p orbital, thereby interrupting the overlap of p orbitals in a continuous manner and preventing the delocalization of π electrons throughout the ring.
Due to the absence of continuous overlap of p...
Due to the absence of continuous overlap of p...
01:28Stability of Conjugated Dienes
Introduction
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
A comparison of the enthalpies of hydrogenation of dienes reveals that conjugated dienes release less heat on hydrogenation, rendering them more stable than their nonconjugated analogs.
01:18Aromatic Hydrocarbon Cations: Structural Overview
Cycloheptatriene is a neutral monocyclic unsaturated hydrocarbon that consists of an odd number of carbon atoms and an intervening sp3 carbon in the ring. The three double bonds in the ring correspond to 6 π electrons, which is a Huckel number, and therefore satisfies the criteria of 4n + 2 π electrons. However, the intervening sp3 carbon disrupts the continuous overlap of p orbitals. As a result, cycloheptatriene is not aromatic.
Removing one hydrogen from the intervening CH2 group with both...
Removing one hydrogen from the intervening CH2 group with both...