Fig. 1: Schematic potential energy surfaces (PESs) for chiral and achiral molecules.
a A barrier separates two minima corresponding to the two enantiomers (E1 and E2): if the interconversion barrier is much higher than the thermal energy (kBT), the molecule is chiral, otherwise rapid interconversion between the two enantiomeric configurations takes place making them inseparable (thermally achiral molecules). b PESs for electronically prochiral molecules which can be converted from achiral to chiral by electronic excitation. The example here shows a case where the molecule is thermally achiral on the ground state, but a similar scenario is also possible where the molecule is truly achiral on the ground state.
