TY - JOUR
T1 - Synthesis of zirconocene amides and ketimides and an investigation into their ethylene polymerization activity
AU - Henderson, K.W.
AU - Hind, A.
AU - Kennedy, A.R.
AU - McKeown, A.E.
AU - Mulvey, R.E.
PY - 2002/8/15
Y1 - 2002/8/15
N2 - The zirconocene amide [Cp2Zr(Cl)N(CH2Ph)(2)] (5), and the zirconbcene ketimides [Cp2Zr(Cl)N=C(Bu')Ph] (7), and [Cp2Zr(Cl)N=C(NMe2)(2)] (9), have been prepared by the transmetallation reactions between the appropriate lithiated organonitrogen compounds and zirconocene dichloride (2). In addition, their methylated derivatives [Cp2Zr(Me)N(CH2Ph)(2)] (6), [Cp2Zr(Me)N=C(Bu')Ph] (8), and [Cp2Zr(Me)N=C(NMe2)(2)] (10), have been prepared by the reaction of each of the complexes 5, 7 and 9 with MeLi. Compounds 5 and 7 have been characterized by X-ray crystallography and the structure of the cocrystalline complex [Cp2Zr(Cl)N=C(Bu)Ph](0.4)[Cp2Zr(Me)N=C(Bu')Ph](0.6) (14), has similarly been determined. All of the complexes 5-10 are active catalysts for the polymerization of ethylene in the presence of a MAO cocatalyst. In contrast, no polymer was produced using B(C6F5)(3) as an activator, indicating that direct alkene insertion into the Zr-N bonds does not occur.
AB - The zirconocene amide [Cp2Zr(Cl)N(CH2Ph)(2)] (5), and the zirconbcene ketimides [Cp2Zr(Cl)N=C(Bu')Ph] (7), and [Cp2Zr(Cl)N=C(NMe2)(2)] (9), have been prepared by the transmetallation reactions between the appropriate lithiated organonitrogen compounds and zirconocene dichloride (2). In addition, their methylated derivatives [Cp2Zr(Me)N(CH2Ph)(2)] (6), [Cp2Zr(Me)N=C(Bu')Ph] (8), and [Cp2Zr(Me)N=C(NMe2)(2)] (10), have been prepared by the reaction of each of the complexes 5, 7 and 9 with MeLi. Compounds 5 and 7 have been characterized by X-ray crystallography and the structure of the cocrystalline complex [Cp2Zr(Cl)N=C(Bu)Ph](0.4)[Cp2Zr(Me)N=C(Bu')Ph](0.6) (14), has similarly been determined. All of the complexes 5-10 are active catalysts for the polymerization of ethylene in the presence of a MAO cocatalyst. In contrast, no polymer was produced using B(C6F5)(3) as an activator, indicating that direct alkene insertion into the Zr-N bonds does not occur.
KW - zirconium
KW - amides
KW - ketimides
KW - catalysis
KW - polymerization
UR - http://dx.doi.org/10.1016/S0022-328X(02)01559-0
U2 - 10.1016/S0022-328X(02)01559-0
DO - 10.1016/S0022-328X(02)01559-0
M3 - Article
SN - 0022-328X
VL - 656
SP - 63
EP - 70
JO - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
IS - 1-2
ER -