Utility of the Nudged Elastic Band Method in Identifying the Minimum Energy Path of an Elementary Organometallic Reaction Step

The
nudged elastic band (NEB) method has been used to re-examine
the oxidative addition step in the classic rhodium-catalyzed hydroacylation
reaction. Numerous additional intermediates were found on a pathway
that is lower in energy than that originally reported. This study
illustrates the potential limitations of the traditional approach
to locating transition states in which a chemical-intuition-guided
linear or quadratic synchronous transit is used to estimate the high
point of the reaction trajectory. Utilization of that approach constrains
the search so that the actual transition state and other possible
intermediates and transition states may be missed.