Density functional study of the Reppe carbonylation of acetylene

The Reppe carbonylation of acetylene has been investigated by both static a nd dynamic density functional methods. Structures of all intermediates and transition states involved in each step of the catalytic cycle have been de termined using gradient-corrected exchange-correlation potentials. Dynamic simulations have been performed on the migrative insertion of CO into the m etal-vinyl bond after CO coordination by the metal and show that the insert ion is preceded by a Berry pseudorotation of the initial pentacoordinated r eagent and occurs via a simultaneous detachment of the vinyl group from the metal and formation of the vinyl-carbonyl bond. The overall thermodynamics and kinetics for the full catalytic cycle have been evaluated and have sho wn that the Reppe carbonylation of acetylene is a thermodynamically favored and kinetically easy process.