Ethylene tetramerization catalyst using the cationic chromium complex
Ethylene tetramerization catalyst using the cationic chromium complex
- 주제(키워드) ethylene tetramerization. cationic chromium complex
- 발행기관 아주대학교
- 지도교수 이분열
- 발행년도 2017
- 학위수여년월 2017. 2
- 학위명 석사
- 학과 및 전공 일반대학원 분자과학기술학과
- 실제URI http://www.dcollection.net/handler/ajou/000000024893
- 본문언어 영어
- 저작권 아주대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Ethylene tetramerization catalyst composed of PNP ligand, Cr(III) complex, and MAO is useful in the production of 1-octene, in which a concern is the use of expensive MAO in excess. Herein, we report a catalytic system that avoids the use of MAO. Metathesis of CrCl3(THF)3 and [(CH3CN)4Ag]+[B(C6F5)4]- afforded [L4CrIIICl2]+[B(C6F5)4]- (L = CH3CN or THF), which was converted to [(PNP)CrCl2L2]+[B(C6F5)4]- where PNP is iPrN(PPh2)2 (1) or [CH3(CH2)16]2CHN(PPh2)2 (2). The molecular structures of [(THF)4CrIIICl2]+[B(C6F5)4]- and [1-CrCl2(THF)2]+[B(C6F5)4]- were unambiguously determined by X-ray crystallography. The cationic (PNP)CrIII complexes paired with [B(C6F5)4]- anion, i.e., [(PNP)CrCl2(CH3CN)2]+[B(C6F5)4]- exhibit high activity in chlorobenzene when activated with common trialkylaluminum (Me3Al, Et3Al, and iBu3Al). The activity and selectivity were comparable to those of the original MAO-based Sasol system (1-CrCl3/MMAO). The Cr complex [2-CrCl2(CH3CN)2]+[B(C6F5)4]- bearing long alkyl chains activated with Et3Al or iBu3Al showed high activity in more desirable methylcyclohexane solvent (89 Kg/g-Cr/h) and much higher activity in cyclohexene bearing -electrons (168 Kg/g-Cr/h). Negligible catalyst deactivation, formation of negligible amount of PE (0.3%), and formation of less amount of unwanted side products above C10 are another advantages gained by the catalytic system [2-CrCl2(CH3CN)2]+[B(C6F5)4]-/Et3Al in cyclohexene. [B(C6F5)4]- anion is compatible with trialkylaluminum in itself once it is not paired with trityl cation, and, hence, [(PNP)CrCl2(CH3CN)2]+[B(C6F5)4]-/Et3Al exhibited high activity in contrast with very low activity of the reported system composed of [Ph3C]+[B(C6F5)4]-, i.e., 1/CrCl3(THF)3/[Ph3C]+[B(C6F5)4]-/Et3Al.
more목차
1. Introduction
2. Results and Discussion
2.1 Preparation of cationic CrIIIcomplexes
2.2 X-ray Crystallographic Studies
2.3 Ethylene Oligomerization Studies
3. Conclusions
4. Experimental Section
4.1 General remarks
4.2 Synthesis of ligands and complexes
4.3 Typical procedure for ethylene oligomerzation
4.4 X-ray Crystallography
5. Acknowledgements
6. Reference
7. Supporting information
