새로운 Nickel화합물의 합성 및 이를 이용한 에틸렌 중합; Grignard reagent를 이용한 실리카 표면개질법의 개발
- 발행기관 아주대학교 일반대학원
- 지도교수 이분열
- 발행년도 2005
- 학위수여년월 2005. 2
- 학위명 석사
- 학과 및 전공 일반대학원 공학계열
- 본문언어 영어
초록/요약
1. [RR’C=NC6H4C(O)O-2N,O]Ni(3-CH2CMeCH2) (R, R’ = -(CH2)5-, 6; R = Et, R’ = Et, 7; R = tBu, R’ = H, 8) are prepared by reaction of the corresponding potassium salts with [(3-CH2CMeCH2)NiCl]2 in CH3CN. Additions of an equivalent of B(C6F5)3 afford zwitterionic complexes, [RR’C=NC6H4C{OB(C6F5)3}O-2N,O]Ni(3-CH2CMeCH2) (R, R’ = -(CH2)5-, 9; R = Et, R’ = Et, 10; R = tBu, R’ = H, 11) which give poly(ethylene) when ethylene gas is added. This result is interesting in that the corresponding 2-(diphenylphosphino)benzoato and 2-(diphenylamino)benzoato complexes give mainly butene. Reactions of the potassium salts with Ni(3-CH2C6H5)Cl(PMe3) afford benzyl complexes, [RR’C=NC6H4C(O)O-2N,O]Ni(1-CH2C6H5)(PMe3) (R, R’ = -(CH2)5-, 12; R = Et, R’ = Et, 13). Additions of two equivalents of B(C6F5)3 to 12 and 13 afford zwitterionic 3-benzyl complexes, [RR’C=NC6H4C{OB(C6F5)3}O-2N,O]Ni(3-CH2C6H5) (R, R’ = -(CH2)5-, 14; R = Et, R’ = Et, 15). Complex 14 is rather unstable and a bis ligand complex, [(CH2)5C=NC6H4C{OB(C6F5)3}O-2N,O]2Ni (16) is formed during recrystallization. Complexes 14 and 15 are highly active to ethylene polymerization and activities reach 3000 - 4000 Kg/(molNi•h) at 75 psig pressure. Solid structures of 6, 9, 11, 15, and 16 were determined by x-ray crystallography. 2. [N-(2-Benzoylphenyl)benzamido-2N,O](1-benzyl)(trimethylphosphine)Ni(II) (3) is prepared by the reaction of potassium N-(2-benzoylphenyl)benzamide and Ni(3-CH2C6H5)Cl(PMe3). When 3 is treated with one equivalent of B(C6F5)3, one obtains a zwitterionic complex, [PhC(O)-C6H4-N=C(Ph)OB(C6F5)3-2N,O]Ni(1-CH2C6H5) (PMe3)(4). When two equivalents of B(C6F5)3 is added, PMe3 is abstracted to give a 3-benzyl zwitterionic complex, [PhC(O)-C6H4-N=C(Ph)OB(C6F5)3-2N,O]Ni(3-CH2C6H5) (5). Solid structures of 4 and 5 were determined by x-ray crystallography. When ethylene is added to 5, low molecular weight polyethylene is obtained. 3. A novel surface modification strategy has been developed by reacting Grignard reagents onto the dehydroxylated silica as shown in equation 1. The route gives not only the formation of a direct Si-C bond, which is much stronger in hydrolytic cleavage, but also preclusion from the formation of both surface bound oligomers and variable modes of attachment. MCM-41,SBA-15 are modified by this strategy using nBuMgCl. High loading of organic groups can be achieved and the mesoporous structures are not destroyed by the modification. Analysis by the 29Si MAS NMR spectrum, 13C CP-MAS NMR spectrum indicate formation of the direct Si-C bond. The modified materials thus obtained exhibit excellent hydrothermal stability by forming direct Si-C bonds. Other functional groups can be attached on the silica surface by this novel method. Treatment of benzyl magnesium chloride and phenyl magnesium bromide on the MCM-41 dehydroxylated at 1123 K provides modified silicas. Attachment of highly functional molecules such as a glucose derivative is also successfully achieved in the present work.
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Contents
Chapter 1. 2-(Alkylideneamino)benzoato Ni(Ⅱ) Complexes: Active Catalysts for Ethylene Polymerization = 1
1. Introduction = 2
2. Result and discussion = 3
3. Experimental section = 16
4. Tables(Crystallographic parameters of compound 6,9,11,15,16) = 28
5. Figures(NMR spectra of compounds) = 31
6. References = 51
Chapteer 2. N-(2-Benzoylphenyl)benzamido nickel(Ⅱ) complexes and polymerization reactivity = 57
1. Introduction = 58
2. Result and discussion = 59
3. Experimental section = 65
4. Figures(NMR spectra) = 70
5. References = 76
Chapter 3. Dehydroxylation Route to Surface Modification of Mesoporous Silicas Using Grignard Reagents = 78
1. Introduction = 79
2. Result and discussion = 80
3. Summary = 83
4. Experimental section = 84
5. Figures = 88
6. References = 94
