Theoretical prediction of the optical rotation of chiral molecules in ordered media: A computational study of (R a)-1,3-dimethylallene, (2 R)-2-methyloxirane, and (2 R )-N-methyloxaziridine

Abstract

A theoretical procedure has been developed and implemented to calculate the optical rotation of chiral molecules in ordered phase via origin-independent diagonal components K´_{xx}(-ω;ω), K´_{yy}(-ω;ω),K´_{zz}(-ω;ω) of the optical activity tensor and origin-independent components A_{αβγ}(-ω;ω), for α≠β≠γ of the mixed electric dipole-electric quadrupole polarizability. Origin independence was achieved by referring tensors to the principal axis system of the electric dipole dynamic polarizability α_{αβ}(-ω;ω) at the same laser frequency ω. The approach has been applied, allowing for alternative quantum mechanical methods based on different gauges, to estimate near Hartree-Fock values for three chiral molecules, (2R)-N-methyloxaziridine C2NOH5, (2R)-2-methyloxirane (also referred to as propylene oxide) C3OH6, and (Ra )-1,3-dimethylallene C5H8, at two frequencies. The theoretical predictions can be useful for an attempt at measuring correspondent experimental values in crystal phase.