A Mechanistic Investigation of the Polymerization of Ethylene Catalyzed by Neutral Ni(II) Complexes Derived from Bulky Anilinotropone Ligands
作者:Jason C. Jenkins、Maurice Brookhart
DOI:10.1021/ja030634g
日期:2004.5.1
completely to the alkyl olefin complex. Under these conditions, the barriers to migratory insertion were determined to be ca. 16-17 kcal/mol for 9a, 9c, 9d, and 16a. Extraction of 2,6-lutidine from complexes 16a,b yields highly dynamic beta-agostic alkyl complexes [[(2,6-i-Pr(2)C(6)H(3))NC(7)H(5)O]Ni(Et)] 21 and [[(2,6-i-Pr(2)C(6)H(3))NC(7)H(5)O]Ni(i-Pr)] 22. Free energy barriers to nickel-carbon bond
对衍生自庞大苯胺酮配体的中性 Ni(II) 催化剂催化的乙烯聚合进行了广泛的机理研究。制备的配合物和预催化剂包括芳基衍生物 [(2,6-i-Pr(2)C(6)H(3))NC(7)H(4)O(7-Aryl)Ni(Ph)(PPh(3) ))] (9, Aryl = 苯基(a), 1-萘基(b), 对甲氧基苯基(c), 对三氟甲基苯基(d)), 烷基衍生物[[(2,6-(i)Pr(2) )C(6)H(3))NC(7)H(5)O]Ni(R)(2,4-二甲基吡啶)] (16, R = Et (a), n-Pr (b)) 和[[(2,6-(i)Pr(2)C(6)H(3))NC(7)H(5)O]Ni(R)(PPh(3))] (17, R = Et (a)、n-Pr (b)、n-己基 (c)、i-Pr (d)) 和镍氢化物配合物 [[(2,6-(i)Pr(2)C(6)H) (3))NC(7)H(5)O]N