Towards detection of the molecular parity violation in chiral Ru(acac)$_3$ and Os(acac)$_3

An investigation of a helically chiral compound Ru(acac)$_3$ shows its potential for the experimental detection of parity violation (PV) in a molecular system. An experiment measuring PV frequency shifts $\Delta \nu^\text{PV}$ in vibrational spectra of Ru(acac)$_3$ is being built at Laboratoire de Physique des Lasers in Paris. Based on our relativistic calculations, the most promising vibrational modes are identified with fractional shifts $\Delta\nu^\text{PV}/\nu$ reaching up to two orders of magnitude higher ($\sim 10^{-13}$) compared to the projected instrumental sensitivity ($\sim 10^{-15}$). The related heavier homologoue Os(acac)$_3$ exhibits even higher relative PV shifts extending up to $\Delta\nu^\text{PV}/\nu\sim 10^{-12}$ strongly motivating its future synthesis and characterization.