Optical enantioselection in a random ensemble of unidirectionally oriented chiral olefins

A laser control scenario for selective excitation of chiral molecules in a random ensemble of unidirectionally oriented racemic mixtures is presented. This selection is carried out using two linearly polarized phase-locked pulses. The two pulses are propagating perpendicular to each other, and polarizations are such that for defined molecular orientations the interaction with one selected enantiomer vanishes, while that with the other is maximized. The method is demonstrated by numerical simulations in all possible orientations around a fixed axis of the axial chiral olefin (4-methyl-cyclohexylidene)fluoromethane. After the pulse sequence, ca. 10% enantiomeric excess is created in the excited singlet electronic state on a picosecond time scale