Retro-Brook rearrangement induces the formation of an octahedral nickel(benzamidinate) complex; Synthesis, structure and catalytic activity

TY - JOUR

T1 - Retro-Brook rearrangement induces the formation of an octahedral nickel(benzamidinate) complex; Synthesis, structure and catalytic activity

AU - Nelkenbaum, Elza

AU - Kapon, Moshe

AU - Eisen, Moris S.

N1 - Funding Information: This research was supported by the German Israel Foundation under Contract I-621-27.5/1999 and by the Fund for the Promotion of Research at the Technion. We thank Mrs. Ella Shaviv for the ligand and Dr. Victoria Volkis for the GPC measurements.

PY - 2005/4/29

Y1 - 2005/4/29

N2 - The neutral octahedral nickel complex (PhC(NSiMe3)NC(Ph) CHSiMe3)Ni(acac)(TMEDA) (7), has been synthesized and characterized including X-ray diffraction analysis. The complex was formed by the reaction of Ni(acac)2(TMEDA) with the lithium salt of the corresponding β-diketiminate ligand. The formation of the benzamidinate motif from the corresponding β-diketiminate is a consequence of a retro-Brook isomerization that is operative only at the nickel centre. A plausible mechanism for the metal mediated isomerization is proposed. When complex 7 was activated with MAO it showed a good catalytic activity for the addition polymerization of norbornene. Furthermore, this catalytic system has been found to oligomerize ethylene to a mixture of butenes and hexenes with a high turnover frequency, η = 29,300 h-1, when the reaction is performed in dichloromethane.

AB - The neutral octahedral nickel complex (PhC(NSiMe3)NC(Ph) CHSiMe3)Ni(acac)(TMEDA) (7), has been synthesized and characterized including X-ray diffraction analysis. The complex was formed by the reaction of Ni(acac)2(TMEDA) with the lithium salt of the corresponding β-diketiminate ligand. The formation of the benzamidinate motif from the corresponding β-diketiminate is a consequence of a retro-Brook isomerization that is operative only at the nickel centre. A plausible mechanism for the metal mediated isomerization is proposed. When complex 7 was activated with MAO it showed a good catalytic activity for the addition polymerization of norbornene. Furthermore, this catalytic system has been found to oligomerize ethylene to a mixture of butenes and hexenes with a high turnover frequency, η = 29,300 h-1, when the reaction is performed in dichloromethane.

KW - Diketiminates

KW - Ethylene oligomerization

KW - Nickel

KW - Polymerization

KW - Retro brook isomerization

KW - X-ray structure

UR - http://www.scopus.com/inward/record.url?scp=17444391268&partnerID=8YFLogxK

U2 - 10.1016/j.jorganchem.2005.02.040

DO - 10.1016/j.jorganchem.2005.02.040

M3 - 文章

AN - SCOPUS:17444391268

SN - 0022-328X

VL - 690

SP - 2297

EP - 2305

JO - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

IS - 9

ER -