Orientated molecular information from chiral rotational spectroscopy

We present details on how the newly introduced technique of chiral rotational spectroscopy can be used to extract orientated information from otherwise freely rotating molecules in the gas phase. In this technique circularly polarized light is used to illuminate chiral molecules and shift their rotational levels to yield orientated chiroptical information via their rotational spectrum. This enables in particular the determination of the individual, physically relevant components of the orientated optical activity pseudotensor. Using the explicit example of (S)-propylene glycol we show how measuring the rotational spectrum of molecules in the microwave domain allows for the recording of a small set of rotational transitions from which the individual polarizability components can be determined.