在离子液体中的衍生物的相图
Satoshi Watanabe1, Keigo Ono2, Rinsuke Nakayama2
1Division of Applied Chemistry and Biochemistry, Naitonal Institute of Technology, Tomakomai College, Nishikioka 443, Tomakomai, Hokkaido, 059-1275, Japan.
概括
研究人员探索了离子液体,用于 π 结合分子的可重复晶体工程. 这种不易挥发的方法精确地控制了核和生长,克服了传统印刷技术对先进材料性能的局限性.
科学领域:
- 材料科学 材料科学 材料科学
- 晶体学 晶体学是指结晶学.
- 超分子化学 超分子化学
背景情况:
- π结合分子的单晶化对于电子,光子和机械性质至关重要.
- 传统的印刷技术面临复制性问题,因为难以控制溶剂蒸发.
研究的目的:
- 研究用于非挥发性晶体工程的离子液体中的烯衍生物的相位图.
- 确定这些系统中核和晶体生长的关键点.
主要方法:
- 合成和特征的离子液体与酸和 bis ((fluorosulfonyl) amide 离子.
- 研究了在温度范围 (0°C至200°C) 的选定离子液体中对烯和9,10-二甲的溶解度和相位行为.
- 确定了结晶核形成 (沉温度) 和结晶生长 (溶解性) 的关键点.
主要成果:
- 确定了特定的离子液体作为广泛的温度范围内的烯衍生物的有效溶剂.
- 在与有机溶剂相比的离子液体中 (高达100毫米) 实现了烯衍生物的溶解度.
- 在离子液体中观察到溶解和沉温度之间的显著差异,表明与有机溶剂相比,超和区域更大.
结论:
- 离子液体为 π 结合分子的非挥发性晶体工程提供了一个可行的平台.
- 离子液体的调节性质允许精确控制核和晶体生长,提高可重现性.
- 这种方法有助于开发具有定制电子,光子和机械性能的材料.
相关概念视频
01:18Aromatic Hydrocarbon Anions: Structural Overview
2.8K
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...
Due to the absence of continuous...
2.8K
01:18Aromatic Hydrocarbon Cations: Structural Overview
2.8K
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...
Removing one hydrogen from the intervening CH2 group...
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01:17Thermal Electrocyclic Reactions: Stereochemistry
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The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
2.0K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
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Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.3K
01:25Basicity of Heterocyclic Aromatic Amines
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Heterocyclic amines, where the N atom is a part of an alicyclic system, are similar in basicity to alkylamines. Interestingly, the heterocyclic amine having a nitrogen atom as part of an aromatic ring has much less basicity than its corresponding alicyclic counterpart. For this reason, as presented in Figure 1, piperidine (pKb = 2.8) is significantly more basic than pyridine (pKb = 8.8).
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01:26Photochemical Electrocyclic Reactions: Stereochemistry
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The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
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