Preparation of Pyridylamido Hafnium Complexes for Olefin Polymerization
- 주제(키워드) pyridylamido hafnium complex , coordinative chain transfer polymerization , dialkylzinc , post-metallocene
- 발행기관 아주대학교
- 지도교수 이분열
- 발행년도 2020
- 학위수여년월 2020. 8
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000030297
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
The pyridylamido hafnium complex (I) discovered at Dow is a flagship catalyst among postmetallocenes, which are used in the polyolefin industry for PO-chain growth from a chain transfer agent, dialkylzinc. In the present work, with the aim to block a possible deactivation process in prototype compound I, the corresponding derivatives were prepared. A series of pyridylamido Hf complexes were prepared by replacing the 2,6-diisopropylphenylamido part in I with various 2,6-R2C6H3N- moieties (R = cycloheptyl, cyclohexyl, cyclopentyl, 3-pentyl, ethyl, or Ph) or by replacing 2-iPrC6H4C(H)- in I with the simple PhC(H)- moiety. The isopropyl substituent in the 2-iPrC6H4C(H)- moiety influences not only the geometry of the structures (revealed by X-ray crystallography) but also catalytic performance. In the complexes bearing the 2-iPrC6H4C(H)- moiety, the chelation framework forms a plane; however, this framework is distorted in the complexes containing the PhC(H)- moiety. The ability to incorporate a-olefin decreased upon replacing 2-iPrC6H4C(H)- with the PhC(H)- moiety. The complexes carrying the 2,6-di(cycloheptyl)phenylamido or 2,6-di(cyclohexyl)phenylamido moiety (replacing the 2,6-diisopropylphenylamido part in I) showed somewhat higher activity with greater longevity than did prototype catalyst I.
more목차
1. Introduction 1
2. Results and Discussion 4
2.1 Preparation of Hf complexes 4
2.2 X-ray crystallographic analyses 8
2.3 Polymerization experiments 12
3. Conclusions 14
4. Experimental Section 16
4.1 General remarks 16
4.2 A typical CCTP 27
4.3 Ethylene polymerization with flowmeter 28
4.4 High-temperature GPC studies 29
4.5 X-ray crystallography 29
4.6 Crystallographic data on compound 30
5. Acknowledgements 31
6. Reference 31
7. Supporting information 40
