Tuning of isobutylene polymerization by Lewis acid catalytic Systems: Is a duo better than one?

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis Pub Date : 2024-11-22 DOI:10.1016/j.mcat.2024.114692

Qinghua Guo , Xing Guo , Jiale Niu , Xinyi Yang , Boping Liu , Zhen Liu

{"title":"Tuning of isobutylene polymerization by Lewis acid catalytic Systems: Is a duo better than one?","authors":"Qinghua Guo , Xing Guo , Jiale Niu , Xinyi Yang , Boping Liu , Zhen Liu","doi":"10.1016/j.mcat.2024.114692","DOIUrl":null,"url":null,"abstract":"<div><div>The FeCl3·phenetole/TiCl4·H2O catalytic system was investigated for the synthesis of medium molecular weight polyisobutylene (MPIB). The dual Lewis acid system showed a remarkable synergistic effect on the catalytic efficiency. The much higher monomer conversion was achieved with the dual Lewis acid system than that with the FeCl3·phenetole system. Notably, the PIB with number average molecular weight up to 18,500 g mol-1 was obtained with 93 % conversion in 10 min by the dual Lewis acid system. DFT calculations revealed a dimeric FeCl3/TiCl4 geometry for the FeCl3·phenetole/TiCl4·H2O complex, in which H2O simultaneously binds to the Fe center and the Ti center. The most plausible mechanism for the initiation reaction follows a proton transfer from the H2O molecule to a nearby isobutylene molecule in the FeCl3·phenetole/TiCl4·H2O system, which is favored in terms of energy barrier with comparison to the reaction initiated by the FeCl3·phenetole system.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"571 ","pages":"Article 114692"},"PeriodicalIF":3.9000,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular Catalysis","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2468823124008745","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}

引用次数: 0

Abstract

The FeCl₃·phenetole/TiCl₄·H₂O catalytic system was investigated for the synthesis of medium molecular weight polyisobutylene (MPIB). The dual Lewis acid system showed a remarkable synergistic effect on the catalytic efficiency. The much higher monomer conversion was achieved with the dual Lewis acid system than that with the FeCl₃·phenetole system. Notably, the PIB with number average molecular weight up to 18,500 g mol^-1 was obtained with 93 % conversion in 10 min by the dual Lewis acid system. DFT calculations revealed a dimeric FeCl₃/TiCl₄ geometry for the FeCl₃·phenetole/TiCl₄·H₂O complex, in which H₂O simultaneously binds to the Fe center and the Ti center. The most plausible mechanism for the initiation reaction follows a proton transfer from the H₂O molecule to a nearby isobutylene molecule in the FeCl₃·phenetole/TiCl₄·H₂O system, which is favored in terms of energy barrier with comparison to the reaction initiated by the FeCl₃·phenetole system.

Abstract Image

查看原文本刊更多论文

路易斯酸催化系统对异丁烯聚合的调谐：双人组合比单人组合更好吗？

研究了用于合成中分子量聚异丁烯（MPIB）的 FeCl3-苯乙醚/TiCl4-H2O 催化体系。双路易斯酸体系对催化效率有显著的协同作用。与 FeCl3-苯乙醚体系相比，双路易斯酸体系实现了更高的单体转化率。值得注意的是，双路易斯酸体系在 10 分钟内获得了平均分子量高达 18,500 g mol-1 的 PIB，转化率为 93%。DFT 计算显示，FeCl3-苯乙醚/TiCl4-H2O 复合物具有二聚 FeCl3/TiCl4 几何结构，其中 H2O 同时与 Fe 中心和 Ti 中心结合。在 FeCl3-苯乙醚/TiCl4-H2O 体系中，启动反应的最合理机制是质子从 H2O 分子转移到附近的异丁烯分子，与 FeCl3-苯乙醚体系启动的反应相比，这种机制在能障方面更有利。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Molecular Catalysis Chemical Engineering-Process Chemistry and Technology

CiteScore

6.90

自引率

10.90%

发文量

700

审稿时长

40 days

期刊介绍： Molecular Catalysis publishes full papers that are original, rigorous, and scholarly contributions examining the molecular and atomic aspects of catalytic activation and reaction mechanisms. The fields covered are: Heterogeneous catalysis including immobilized molecular catalysts Homogeneous catalysis including organocatalysis, organometallic catalysis and biocatalysis Photo- and electrochemistry Theoretical aspects of catalysis analyzed by computational methods