Computing the arrows of chemical reactions

Abstract

The use of curved arrows to describe the movement of electrons in chemical reaction schemes is widespread in several areas of chemistry, especially organic chemistry. The drawing of such arrows is guided by chemical intuition on the nature of nucleophiles and electrophiles. Here we show that it is actually possible to compute arrows from single-determinant computational quantum chemistry calculations. The procedure, which is outlined for the aldol reaction, is based on the computation of localized orbitals and their centroids along the intrinsic reaction coordinate.