Preparation of Extremely Active Ethylene Tetramerization Catalyst [iPrN(PAr2)2−CrCl2]+[B(C6F5)4]– (Ar = −C6H4-p-SiR3)
- 주제(키워드) Ethylene tetramderization , 1-octene production , chromium catalyst , bis(phosphine)ligand , tetrakis(pentafluorophenyl)borate
- 주제(DDC) 547
- 발행기관 아주대학교
- 지도교수 이분열
- 발행년도 2022
- 학위수여년월 2022. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000031340
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Numerous efforts have been made to achieve “on-purpose” 1-octene production since Sasol discovered a Cr-based selective ethylene tetramerization catalyst in the early 2000s. By preparing a series of bis(phosphine) ligands iPrN(PAr2)2 where the Ar contains a bulky –SiR3 substituent (Ar = -C6H4-p-Si(nBu)3 (1), -C6H4-p-Si(1-hexyl)3 (2), -C6H4-p-Si(1-octyl)3 (3), -C6H4-p-Si(2-ethylhexyl)3 (4), -C6H4-p-Si(3,7-dimethyloctyl)3 (5)), we obtained an extremely active catalyst that meets the criteria for commercial utilization. The Cr complexes [iPrN(PAr2)2-CrCl2]+[B(C6F5)4]–, obtained by reacting ligands 1-5 with [(CH3CN)4CrCl2]+[B(C6F5)4]–, showed high activity exceeding 6000 kg/g-Cr/h, when combined with the inexpensive iBu3Al, thus avoiding the use of expensive modified methylaluminoxane (MMAO). The bulky –SiR3 substituents played a key role in the success of catalysis by blocking the formation of inactive species (Cr complexes coordinated by two iPrN(PAr2)2 ligands, that is, [(iPrN(PAr2)2)2-CrCl2]+[B(C6F5)4]–). Among the complexes prepared, [3-CrCl2]+[B(C6F5)4]– exhibited the highest activity (11,100 kg/g-Cr/h, 100 kg/g-catalyst) with high 1-octene selectivity (75 wt%), and, moreover, mitigated the generation of undesired > C10 fractions (10.7 wt%). A 10-g-scale synthesis of 3 was developed, as well as a facile and low-cost synthetic method for [(CH3CN)4CrCl2]+[B(C6F5)4]–.
more목차
1. Introduction 1
2. Results and Discussion 2
2.1 Preparation of Ligand 2
2.2 Preparation of Chromium Complexes 8
2.3 Oligomerization studies 10
3. Experimental Section 13
3.1 General remarks 13
3.2 (1-Octyl)3SiCl 13
3.3 BrC6H4-p-Si(1-octyl)3 14
3.4 Et2NP[C6H4-p-Si(1-octyl)3]2 14
3.5 ClP[C6H4-p-Si(1-octyl)3]2 15
3.6 iPrN(PAr2)2 (Ar = - C6H4-p-Si(1-octyl)3) 15
3.7 Preperation of [iPrN(PAr2)2-CrCl2]+[B(C6F5)4]- Using [CrCl2(NCCH3)4]+ [B(C6F5)4]- 16
3.8 Attempt to Prepare [iPrN(PAr2)2-CrCl2]+[B(C6F5)4]– Using [PhN(H)Me2]+ [B(C6F5)4]– and [CrCl2(μ-Cl)(thf)2] 16
3.9 [CrCl2(NCCH3)4]+[B(C6F5)4]– 17
3.10 Ethylene Tetramerization 17
4.Conclusions 18
5. Patent 18
6. References 19
