Isotopic effects on the control of molecular handedness of H 2 POSH by ultrashort laser pulses

The selective preparation of an enantiomer starting from a pure state of H₂POSH representing a 50%:50% mixture of two enantiomers with opposite chiralities is extended to its deuterated counterpart, H₂POSD. A one-dimensional model involving the torsional angle of S-H/D around a pre-oriented P-S axis is used. The design of an appropriate sequence of ultrashort infrared laser pulses to achieve molecular handedness for H₂POSH/D is based on the characteristic level splitting and tunneling times of both molecules. A simple scheme of two linearly polarized laser pulses involving a three level system serves to convert the different isotopomers to opposite enantiomers, for any given mixture of H₂POSH and H₂POSD molecules. Received 31 August 2000 and Received in final form 23 November 2000