title: Theoretical analysis of factors controlling the nonalternating CO/C(2)H(4) copolymerization.
abstract: A [P-O]Pd catalyst based on o-alkoxy derivatives of diphenylphosphinobenzene sulfonic acid (I) has recently been shown by Drent et al. to perform nonalternating CO/C(2)H(4) copolymerization with subsequent incorporation of ethylene units into the polyketone chain. The origin of the nonalternation is investigated in a theoretical study of I, where calculated activation barriers and reaction heats of all involved elementary steps are used to generate a complete kinetic model. The kinetic model is able to account for the observed productivity and degree of nonalternation as a function of temperature. Consistent with the energy changes obtained for the real catalyst model, the selectivity toward a nonalternating distribution of both comonomers appears to be mainly a result of a strong destabilization of the Pd-acyl complex.
authors.affiliation: Department of Chemistry, University of Calgary, University Drive 2500, Calgary, Alberta, Canada T2N 1N4.
authors.forename: Alicja
authors.initials: A
authors.lastname: Haras
authors.forename: Artur
authors.initials: A
authors.lastname: Michalak
authors.forename: Bernhard
authors.initials: B
authors.lastname: Rieger
authors.forename: Tom
authors.initials: T
authors.lastname: Ziegler