Density Functional Theory As a Practical Tool in Transition Metal Chemistry. Modeling the Real Thing. Tom Ziegler , Peter M. Margl , Tom K. Woo ,Rochus Schmid, Stephan Wolff , and Cory Pye. Department of Chemistry University of Calgary, Calgary,Alberta,Canada T2N 1N4.

We describe the use and implementation of density functional theory (DFT) based modeling tools of interest for studies of transition metal complexes and homogeneous catalysis. In the first place, we have developed DFT based methods for the calculation of IR [1], NMR [2] and ESR [3] parameters to aid in the spectroscopic identification of reactive intermediates by experimental techniques. Further, effects due to steric bulk and solvation have been included by a combined quantum mechanical and molecular mechanical approach (QM/MM) [4] augmented by the conductor-like screening model (COSMO) [5]. We describe finally an approach in which Car-Parrinello [6] type first principle molecular dynamics (FPMD) calculations based on DFT and the projector augmented-wave method [7] are employed in order to include [8] kinetic and entropic effects into the modeling of reactivity - with or without the use of QM/MM and COSMO. The approaches will be illustrated by applications to (a) a comparison between rhodium and iridium based catalysts in the Monsanto's acetic acid process (b) copolymerization of polar and non-polar monomers by palladium based catalysts [9] as well as (c) carbonylation [10] of methane by a rhodium catalyst.

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