It is widely accepted that steric interactions influence the bond strengths between a ligand and a transition metal in a complex. In the case of olefins as ligands, however, the extent of this influence has not been incorporated in the model used to describe a metal-olefin interaction. Here we present a computational (DFT) study that quantitative describes the role of steric interactions in the bonding of a series of phenylethylenes (C2H4-n(Ph)n, Ph = phenyl, n = 0 � 4) to M(CO)5 (M = Cr, Mo, W).  The results indicate that there is almost a linear decrease of the bond strength with the increase of the number of phenyl substituents and that triphenylethylene and tetraphenylethylene will not make stable olefin complexes. Indeed, results indicate that ?2 bonding to a phenyl substituent would be preferred when steric interactions restrict binding to the olefin.

Computational study of phenylethylene pentacarbonyl metal (chromium, molybdenum and tungsten) complexes: The influence of steric effects on metal-olefin bonding

245th National Meeting (2013)

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