The effect of solvent on a reaction is usually considered in terms of its thermodynamic impact with little regard for the steric effect despite the fact that countless chemical reactions depend on the solvent.
A team led by researchers at the University of Innsbruck, Austria, have probed the influence of individual solvent molecules on reaction dynamics in the chemically important nucleophilic substitution reaction. They investigated the reaction of hydroxyl ions with iodomethane with combined crossed-beam imaging and a cold source of icrosolvated reactants.
The team found that surprisingly, the classical co-linear substitution mechanism only dominates the dynamics for mono-solvated reactants. Subsequent calculations confirmed that steric characteristics are at least as important as the energetics in this reaction for an understanding of the influence of solvent molecules on such microsolvated reactions.
- Single solvent molecules can affect the dynamics of substitution reactions,
R. Otto, J. Brox, S. Trippel, M. Stei, T. Best & R. Wester
Nature Chem. 2012.