Zirconium Complexes of a Cross-Bridged Cyclam
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- 作者：Paul O'Connor ; David J. Berg ; and Brendan Twamley
- 刊名：Organometallics
- 出版年：2005
- 出版时间：January 3, 2005
- 年：2005
- 卷：24
- 期：1
- 页码：28 - 36
- 全文大小：174K
- 年卷期：v.24,no.1(January 3, 2005)
- ISSN：1520-6041
文摘
The acid-base reaction of tetrabenzylzirconium with 1,4,8,11-tetraazabicyclo[6.6.2]hexadecane (H2(CBC), 1) produces (CBC)Zr(CH2Ph)2, 2. Similarly, reaction of 2 with phenolsyields (CBC)Zr(CH2Ph)(O-2,6-C6H3But2), 3, and (CBC)Zr(O-2,6-C6H3Me2)2, 5. Prolongedheating of 3 leads to the metalated product (CBC)Zr[
2(C,O)-OC6H3(6-But)(2-CMe2CH2)], 4.Reaction of ZrCl2[N(SiMe3)2]2 with H2(CBC) leads to (CBC)ZrCl2, 6, which subsequentlyaffords (CBC)Zr(X)(Y) by salt metathesis (7, X = Cl, Y = N(SiMe3)2; 8, X = Y = CH3; 9, X =Y = CH2Si(CH3)3). Compounds 3 and 7 show restricted rotation about the Zr-O and Zr-Nbonds, respectively, on the NMR time scale. For 3, the energy of activation for this processwas determined to be 69 ± 1 kJ/mol. Neither 6 nor 8 shows ethylene polymerization activitywhen treated with 500 equiv of MAO. Reaction of 6 with 2 equiv of n-BuLi in the presenceof excess diphenylacetylene leads to the zirconacyclopentadiene 10, (CBC)Zr(C4Ph4). Thestructures of 5, 9, and 10 have been determined by X-ray crystallography, and all threedisplay distorted octahedral geometry.
2(C,O)-OC6H3(6-But)(2-CMe2CH2)], 4.Reaction of ZrCl2[N(SiMe3)2]2 with H2(CBC) leads to (CBC)ZrCl2, 6, which subsequentlyaffords (CBC)Zr(X)(Y) by salt metathesis (7, X = Cl, Y = N(SiMe3)2; 8, X = Y = CH3; 9, X =Y = CH2Si(CH3)3). Compounds 3 and 7 show restricted rotation about the Zr-O and Zr-Nbonds, respectively, on the NMR time scale. For 3, the energy of activation for this processwas determined to be 69 ± 1 kJ/mol. Neither 6 nor 8 shows ethylene polymerization activitywhen treated with 500 equiv of MAO. Reaction of 6 with 2 equiv of n-BuLi in the presenceof excess diphenylacetylene leads to the zirconacyclopentadiene 10, (CBC)Zr(C4Ph4). Thestructures of 5, 9, and 10 have been determined by X-ray crystallography, and all threedisplay distorted octahedral geometry.