Density functional theory (DFT) calculations have been carried out to study associative (I) and dissociative (II) mechanisms of the rhodium(I)-catalyzed olefin boration reactions, RhCl(PH3)2 + XB(OH)2 + C2H4 ? RhCl(PH3)2 + XC2H4B(OH)2 (1) with X = H, TeH

Ti(XCHX)R(+) and Ti(XCH₂CHCH₂X)R(+) (X= CH₂, SiH₂, NH, PH, O, S) as Olefin Polymerization Catalysts and the Role of Ligand Conjugation. A Combined Density Functional Theory and Valence Bond Study.

Tim Firman and Tom Ziegler Department of Chemistry, University of Calgary, 2500 University Drive N. W., T2N 1N4 Calgary, Alberta, Canada Density functional theory (DFT) calculations have been carried out on the ability of Ti(XCHX)R(+) and Ti(XCH₂CHCH₂X)R(+) (X= CH₂, SiH₂, NH, PH, O, S) to act as olefin polymerization catalysts. Special interest has been given to the role of conjugation in lowering the barrier of insertion. The calculated trends are interpreted in terms of concepts based on valence bond theory.