중합촉매: 한 분자내 두 금속 또는 두 성분을 포함하는 뒷 전이금속 촉매
Polymerization Catalysts: Bimetallic and Binary Systems of Late Transition Metals in a Molecule
- 주제(키워드) 중합촉매 , 뒷전이금속 촉매 , Polymerization Catalysts
- 발행기관 아주대학교 대학원
- 지도교수 이분열
- 발행년도 2008
- 학위수여년월 2008. 8
- 학위명 박사
- 학과 및 전공 일반대학원 분자과학기술학과
- 본문언어 영어
초록/요약
1. A highly active catalytic system for CO2/(propylene oxide) copolymerization was prepared based on the concept of a stystem containing a Lewis acidic metal center and quarternary ammonium salts units. The catalytic system showed high activity (TON >20000; TOF >20000 h-1) even at high temperature and high [epoxide]/[catalyst] ratio and selectively producing a very high molecular-weight copolymer (Mn, 300,000). The catalyst can be easily separated by filtration through a short pad of silica gel to obtain polymer containing negligible amounts of metal residue (1-2 ppm). The separated catalyst can be reused without significant loss in catalytic performance. 2. Bimetallic salicylaldimine-nickel complexes, bridge{[(2,6_(-i)Pr₂C_(6)H₂)-N=CH-(2- anthracenyl- C_(6)H₃-O)-κ²-N,O]Ni(η³-CH₂Ph)}₂ (bridge = ortho-C_(6)H₄, CH₂, ortho- C_(6)H₄(C_(6)H₄)₂,), are prepared. The bimetallic complexes show higher activities and higher polar monomer incorporations in the ethylene/2-(methoxycarbonyl)norbornene and ethylene/2-(acetoxymethyl)norbornene copolymerizations than the mononuclear complex, [(2,6-iPr₂C_(6)H₃)-N=CH-(2-anthracenyl-C_(6)H₃-O)- κ²-N,O]- Ni(η³-CH₂Ph). 3. Neutral η¹-benzylnickel carbene complexes, [Ni(η¹-CH₂C_(6)H_(5))(IiPr)(PMe3)(Cl)] (3) (IiPr = 1,3-bis-(2, 6-diisopropylphenyl)imidazol-2-ylidene) and [Ni(η¹- CH₂C_(6)H_(5))(SIiPr)(PMe3)(Cl)] (4) (SIiPr = 1,3-bis-(2, 6-diisopropylphenyl)imidazolin-2- ylidene), were prepared by the reaction between [Ni(η³- CH₂C_(6)H_(5))(PMe3)(Cl)] and an equivalent amount of the corresponding free N-heterocyclic carbene. The preparation of η³- benzylnickel carbene complexes, [Ni(η³-CH₂C_(6)H_(5))(IiPr)(Cl)] (5) and [Ni(η³- CH₂C_(6)H_(5))(SIiPr)(Cl)] (6) were carried out by the abstraction of PMe3 from 3 and 4 by the treatment of B(C_(6)F_(5))₃. The treatment of AgX on 5 and 6 produced the anion-exchanged complexes, [Ni(η³-CH₂C_(6)H_(5))(NHC)(X)] (7, NHC = IiPr, X = O₂CCF₃; 8, NHC = IiPr, X = O3SCF3; 9, NHC = SIiPr, X = O₂CCF₃; 10, NHC = SIiPr, X = O₃SCF₃). The solid state structures of 3 and 10 were determined by X-ray crystallography. The η³-benzyl complexes of IiPr (5, 7, and 8) alone, in the absence of any activators such as borate and MAO, showed good catalytic activity towards the vinyl-type norbornene polymerization. The catalyst was thermally robust and the activity increases as the temperature rises to 130 °C.
more목차
CHAPTER 1. Introduction = 1
CHAPTER 2. Highly Active and Recyclable Catalytic System For CO2/(Propylene Oxide) Copolymerization = 18
2.1 Introduction = 19
2.2 Results and discussion = 23
2.2.1 Syntheses and Characterization = 23
2.2.2 Polymerization Studies = 26
2.2.3 Catalyst recovery Strategy = 29
2.3 Conclusion = 35
2.4 Experimental Section = 36
2.5 References = 63
2.6 Figures (NMR Spectra) = 66
CHAPTER 3. Ethylene/Polar Norbornene Copolymerization by Bimetallic Salicylaldimine-Nickel Catalysts = 92
3.1 Introduction = 93
3.2 Results and discussion = 94
3.2.1 Syntheses and Characterization = 94
3.2.2 Polymerization Studies = 97
3.2.3 Theoretical Calculations = 103
3.3 Conclusion = 104
3.4 Experimental Section = 105
3.5 References = 113
3.6 Figures (NMR Spectra) = 117
CHAPTER 4. Synthesis, Characterization and Norborne polymerization of ?3-benzylnickel(II) complexes of N-heterocyclic carbene = 128
4.1 Introduction = 129
4.2 Results and discussion = 129
4.2.1 Syntheses and Characterization = 129
4.2.2 X-ray Crystallographic Studies = 131
4.2.3 Polymerization Studies = 134
4.3 Conclusion = 137
4.4 Experimental Section = 137
4.5 References = 144
APPENDIX = 148
1. Preparation andCharacterization of Half-Sandwich Cobalt(III) Complexes of Cp Ligand with a Rigid Thioanisole Side-Chain = 149
2. InAsxSb1-x Alloy Nanocryatals for Use in the Near Infrared = 164
3. Two Components in a Molecule: Highly Efficient and Thermally Robust Catalytic System for CO2/Epoxide Copolymeization = 173
ABBREVIATION = 181
LIST of PUBLICATIONS = 183
