双核宏环双 (?? 胺) 基和铁基催化剂用于乙烯氧化聚合
Mostafa Khoshsefat1, Yanping Ma2, Wen-Hua Sun2,3
1Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi 923-1292, Ishikawa, Japan.
Materials (Basel, Switzerland)
|May 14, 2025
概括
两个新的双核铁 (Fe) 和 (Co) 催化剂有效地将乙烯氧化成有价值的α-olefins (α-C8). 与催化剂 (CC) 相比,铁催化剂 (FC) 对四聚合物生产具有更高的活性和选择性.
科学领域:
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
- 聚合物科学 聚合物科学
背景情况:
- 多核晚期过渡金属复合物对烯寡合化越来越感兴趣.
- 双胺胺) 连接物为设计这种催化剂提供了一个多功能平台.
研究的目的:
- 为了合成和评估二核宏环 bis (((iminopyridine) 铁 (FC) 和 (CC) 复合物用于乙烯寡合化.
- 为了比较FC和CC的催化活性,选择性和稳定性.
主要方法:
- 双核Fe和Co复合物的单模板合成.
- 使用甲基氨酸 (MMAO) 作为辅助催化剂的乙烯寡合化.
- 对催化性能的分析,包括对α-olefins (α-C8) 的活性和选择性.
- 热稳定性测试和分子计算用于结构阐明.
主要成果:
- 在MMAO激活时,FC和CC都表现出合理的活性和高选择性 (>96%) 对于乙烯四化 (α-C8).
- 与CC (8.75 × 10^5 g mol−1 Co h−1, 96.1% α-C8) 相比,FC表现出更高的催化活性 (9.45 × 10^5 g mol−1 Fe h−1) 和选择性 (96.6% α-C8).
- 这两种催化剂在高达70°C的温度下都具有热稳定性,FC比CC表现出更强的活性和稳定性.
结论:
- 双核双 () Fe和Co复合物是选择性乙烯寡合化到α-C8.8的有效催化剂.
- 铁基催化剂 (FC) 在活性和选择性方面提供了优越的性能,与其类型 (CC) 相比.
- 催化剂性能受反应参数的影响,分子建模支持实验发现.
相关概念视频
01:13Olefin Metathesis Polymerization: Overview
2.0K
Recently, the development of olefin metathesis polymerization advanced the field of polymer synthesis. Simply put, the reorganization of substituents on their double bonds between two olefins in the presence of a catalyst is known as the olefin metathesis reaction. The use of metathesis reaction for polymer synthesis is called olefin metathesis polymerization.
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists...
2.0K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.0K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.0K
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
1.9K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
1.9K
01:17Thermal Electrocyclic Reactions: Stereochemistry
1.9K
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.
1.9K
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.5K
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
2.5K
02:50Catalysis
26.4K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
26.4K