The ORCHID project: a search for the Origin of Chiral Discrimination

Control of translational, internal and orientational molecular degrees of freedom in elementary chemical processes constitutes a challenge for the modeling and applications of physical chemistry. In this paper, we focus on the peculiar part arguably played by orientational control for unveiling the stereodynamical nature of processes involving molecular chirality – one of the most fascinating issues of molecular science, crucial in view of the intriguing ubiquitous role of selective left-right asymmetry in the bio-world. Typically, investigations of processes involving explicitly molecular chirality exploit circular polarization, e.g. from laser and/or synchrotron radiation sources. We take an alternative stereodynamical view that relies on advances in molecular-beams orientation techniques: (i) through gas flowing in supersonic regimes, designated as «natural», not requiring external fields and (ii) using electrostatic techniques. These perspective corroborates the following objectives: (a) extension and probing of the natural orientation technique to chiral molecules by elastic and/or inelastic collisions, that permits to design crossed molecular beam experiments to be implemented for the first-time demonstration of left-right spatial asymmetry in molecular encounters; ii) the novel experimental proposals exploiting hexapolar orientation are applied to experiments on the orientation control of molecular collisions in dynamics and photochemistry.