低度氨捕获的自愈结有机框架
Xiyu Song1, Yao Wang1, Chen Wang1
1Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai 200438, China.
Journal of the American Chemical Society
|December 22, 2023
概括
研究人员开发了用于吸收氨的自愈结有机框架 (HOF). 这些材料在暴露于氨气后恢复其晶体结构,使其能够在传感和吸附应用中重复使用.
科学领域:
- 材料科学
- 化学学
- 纳米技术
背景情况:
- 智能传感系统利用自我修复特性进行分子识别.
- 刚性晶体框架通常无法在外部刺激引起的崩后恢复其结构.
- 开发可回收框架对于先进材料应用至关重要.
研究的目的:
- 报告一个新的微孔有机框架的自我愈合行为,FDU-HOF-3.
- 调查FDU-HOF-3的氨 (NH3) 捕获能力,并与HOF-101进行比较.
- 阐明这些框架中自我修复特性背后的机制.
主要方法:
- 合成和描述FDU-HOF-3,一个新的微孔结有机框架.
- 在不同的条件下进行氨 (NH3) 吸附/脱吸试验.
- 使用先进的表征技术分析结构变化和恢复机制.
- 用于评估NH3的传感能力的光流测量.
主要成果:
- 在NH3暴露和真空加热后,FDU-HOF-3表现出可逆的自我愈合,恢复其晶体相.
- 自愈机制涉及酸相互作用 (COOH-NH3) 和键 (COOH-COOH) 动态.
- 在HOF中,FDU-HOF-3表现出了创纪录的氨捕获能力 (8.13 mmol/g,25 mbar).
- 该材料对250ppmNH3具有快速的光电反应,并且在10个吸附释放周期内保持性能.
结论:
- 开发的自愈HOF为强大的氨捕获和传感提供了一个有前途的平台.
- 可逆结构回收机制提高了材料的耐用性和可重复使用性.
- 与现有的HOF相比,FDU-HOF-3在低度氨捕获方面具有更高的性能.
相关概念视频
Hydrogen Bonds
8.5K
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
8.5K
Titration of a Weak Base with a Strong Acid
5.3K
The titration curve of a weak base like ammonia with a strong acid like hydrochloric acid is the mirror image of the titration curve of a weak acid with a strong base.
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
Using the ICE table and substituting the Kb value, we calculate the initial pH of 50 mL of 0.1 M ammonia to be 11.11. Addition of 25 mL of 0.1 M hydrochloric acid to this solution of ammonia results in a buffer with an equal concentration of ammonia and ammonium ions. The pH of this buffer can be calculated by substituting these...
5.3K
Preparation of Amines: Alkylation of Ammonia and Amines
3.4K
Alkylation is one of the methods used to prepare amines. Direct alkylation of ammonia or a primary amine with an alkyl halide gives polyalkylated amines along with a quaternary ammonium salt through successive SN2 reactions. This process of making the quaternary salt through the direct alkylation method is called exhaustive alkylation.
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
3.4K
Weak Base Solutions
22.7K
Some compounds produce hydroxide ions when dissolved by chemically reacting with water molecules. In all cases, these compounds react only partially and so are classified as weak bases. These types of compounds are also abundant in nature and important commodities in various technologies. For example, global production of the weak base ammonia is typically well over 100 metric tons annually, being widely used as an agricultural fertilizer, a raw material for chemical synthesis of other...
22.7K
Preparation of 1° Amines: Gabriel Synthesis
3.6K
Direct alkylation is not a suitable method for synthesizing amines because it produces polyalkylated products. Gabriel synthesis is the most preferred method to exclusively make primary amines. The method uses phthalimide, which contains a protected form of nitrogen that participates in alkylation only once to predominantly give primary amines.
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
Strong bases like NaOH or KOH deprotonate the phthalimide to form the corresponding anion, which acts as a nucleophile. Further, the anion attacks an...
3.6K
Basicity of Aliphatic Amines
5.9K
Amines can behave as Brønsted–Lowry bases by accepting a proton from the acid to form corresponding conjugate acids. Due to a lone pair of nonbonding electrons, aliphatic amines can also act as Lewis bases by forming a covalent bond with an electrophile.
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates...
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates...
5.9K


