Bimetallic synergy in Si-(CH₂)ₙ-Si-bridged binuclear indenyl-pyrrolidinyl titanium catalysts for ethylene/1-octene copolymerization

IF 3.9 2区化学 Q2 CHEMISTRY, PHYSICAL

Molecular Catalysis Pub Date : 2025-04-22 DOI:10.1016/j.mcat.2025.115145

Xiangsheng Mu, Fengxin Yang, Qishun Guo, Yu Zhang, Yanhui Chen, Tao Jiang

{"title":"Bimetallic synergy in Si-(CH₂)ₙ-Si-bridged binuclear indenyl-pyrrolidinyl titanium catalysts for ethylene/1-octene copolymerization","authors":"Xiangsheng Mu, Fengxin Yang, Qishun Guo, Yu Zhang, Yanhui Chen, Tao Jiang","doi":"10.1016/j.mcat.2025.115145","DOIUrl":null,"url":null,"abstract":"<div><div>To investigate the cooperative effect of binuclear metallocene catalysts in olefin polymerization, a series of Si-(CH₂)ₙ-Si bridged binuclear indene pyrrolidine titanium catalysts 2d-7d (Ti2) were synthesized. The mononuclear complex NC₄H₈CpC₆H₄(Me)₂SiN(CH₃)₃TiCl2 (Ti1) was also prepared for control experiments. DFT calculations show that increasing the methylene spacer length (n=2–7) simultaneously enlarges the Ti-Ti distance (8.93–14.65 Å) and reduces the buried volume (%Vbur=16.2–12.4 %). In the presence of [Ph3C][B(C6F5)4] as a co-catalyst, 2d-7d (Ti2) showed higher activity and thermal stability. For ethylene/1-octene copolymers, especially 5d (Ti2) at 120 °C, the activity was 2.65×107 g/(mol·h), the Mw was 66.93×104 g/mol, and the 1-octene insertion rate was 8.4 mol%, which were 1.8 times, 1.9 times, and 1.3 times higher than that of mononuclear 1d (Ti1), respectively. Copolymers from binuclear catalysts showed reduced crystallinity and melting points due to enhanced branching, alongside improved tensile strength and elastic recovery.</div></div>","PeriodicalId":393,"journal":{"name":"Molecular Catalysis","volume":"581 ","pages":"Article 115145"},"PeriodicalIF":3.9000,"publicationDate":"2025-04-22","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/S246882312500330X","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

To investigate the cooperative effect of binuclear metallocene catalysts in olefin polymerization, a series of Si-(CH₂)ₙ-Si bridged binuclear indene pyrrolidine titanium catalysts 2d-7d (Ti₂) were synthesized. The mononuclear complex NC₄H₈CpC₆H₄(Me)₂SiN(CH₃)₃TiCl₂ (Ti₁) was also prepared for control experiments. DFT calculations show that increasing the methylene spacer length (n=2–7) simultaneously enlarges the Ti-Ti distance (8.93–14.65 Å) and reduces the buried volume (%Vbur=16.2–12.4 %). In the presence of [Ph₃C][B(C₆F₅)₄] as a co-catalyst, 2d-7d (Ti₂) showed higher activity and thermal stability. For ethylene/1-octene copolymers, especially 5d (Ti₂) at 120 °C, the activity was 2.65×10⁷ g/(mol·h), the Mw was 66.93×10⁴ g/mol, and the 1-octene insertion rate was 8.4 mol%, which were 1.8 times, 1.9 times, and 1.3 times higher than that of mononuclear 1d (Ti₁), respectively. Copolymers from binuclear catalysts showed reduced crystallinity and melting points due to enhanced branching, alongside improved tensile strength and elastic recovery.

Abstract Image

查看原文本刊更多论文

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