A direct way to observe absolute molecular handedness

TL;DR

This paper introduces a direct experimental method to determine the absolute molecular handedness using electron tunneling polarization, bypassing traditional configuration-based methods and relying on symmetry considerations.

Contribution

It presents a novel approach that directly measures molecular handedness through electron tunneling polarization, avoiding the need for absolute configuration determination.

Findings

Electron tunneling polarization uniquely determines molecular handedness.

Symmetry arguments eliminate the need for fine-structure splitting.

Method is compatible with the CIP convention.

Abstract

Unique labeling of chiral stereo-centers must include their handedness. The conventional method that has been developed to do this was originated by three chemists: R.S. Cahn, C. Ingold, and V. Prelog (CIP) and is formally known as R,S nomenclature. It requires knowledge of the spatial absolute configuration of that center. Traditionally, experimental methods of extracting handedness go through the absolute configuration and only then through the application of the CIP convention. Here we show that a direct experimental method of determination of the natural handedness by the polarization of tunneling electrons is almost always compatible with the CIP convention. By the sole use of symmetry arguments we show that the chiral molecule symmetry withdraws the need of fine structure splitting. As a consequence, the polarization of electrons tunneling through the molecular electric dipole direction uniquely determines their handedness. The symmetry breaking argument that induces lack of fine-structure splitting eliminates the need for a precise value of the spin-orbit interaction.