Elucidation of substituent effects in the polymerization of propylene promoted by titanium amidinates

TY - JOUR

T1 - Elucidation of substituent effects in the polymerization of propylene promoted by titanium amidinates

AU - Aharonovich, Sinai

AU - Botoshansky, Mark

AU - Balazs, Yael S.

AU - Eisen, Moris S.

PY - 2012/4/23

Y1 - 2012/4/23

N2 - In polymerization reactions, the molecular weight of the polymer depends on the rates of monomer insertion, chain termination, and chain transfer. Here we do present studies indicating why chelating octahedral benzamidinate group IV complexes, which promote the polymerization of propylene with MAO, exhibit a linear free energy relationship with the steric Taft parameter. We correlate that this relationship is encountered with the para substituent of the aromatic ring, far away from the active catalytic site. A number of known events are put together to shed light on the effect of the ancillary ligands in the catalytic polymerization, and a new plausible mechanism for the process is presented.

AB - In polymerization reactions, the molecular weight of the polymer depends on the rates of monomer insertion, chain termination, and chain transfer. Here we do present studies indicating why chelating octahedral benzamidinate group IV complexes, which promote the polymerization of propylene with MAO, exhibit a linear free energy relationship with the steric Taft parameter. We correlate that this relationship is encountered with the para substituent of the aromatic ring, far away from the active catalytic site. A number of known events are put together to shed light on the effect of the ancillary ligands in the catalytic polymerization, and a new plausible mechanism for the process is presented.

UR - http://www.scopus.com/inward/record.url?scp=84860328950&partnerID=8YFLogxK

U2 - 10.1021/om300068w

DO - 10.1021/om300068w

M3 - 文章

AN - SCOPUS:84860328950

SN - 0276-7333

VL - 31

SP - 3435

EP - 3438

JO - Organometallics

JF - Organometallics

IS - 8

ER -