Dynamical stereochemistry of elementary reactions in solution

Orientational steric effects in four A + BC → AB + C reactions in the gas phase and in solution are studied by molecular dynamics simulations. We investigate the role of the torque due to the reactant-reactant potential and that due to solvent-reactant interactions. The time scales for the development of the rotational energy and of the orientation needed for reaction are computed, the latter in terms of a BC angular correlation function. The results vary considerably from one type of reaction to another. We find that the gas and solution results are surprisingly similar and that analyses and models familiar from the gas phase, such as the cone of acceptance, can also be useful in solution.