How Important is Parity Violation for Molecular and Biomolecular Chirality?

Abstract

Parity violation leads to energy differences delta(pv)H(o)(0)=N(A)delta(pv)E of enantiomers in the femtojoule to picojoule per mole range. Recently introduced methods of electroweak quantum chemistry predict such energy differences to be one to two orders of magnitude larger than previously accepted-but still very small. How can such small energies be measured and what are the consequences for our understanding of molecular chirality, biomolecular homochirality, and perhaps fundamental physics? The review gives some tentative answers to these questions. We discuss the current status of theory and some of the current experimental approaches.

Sum-Frequency Generation from Chiral Media and Interfaces

“…This result is unlike other proposed measurements of PNC which are linear in the parity violating potential [99,100,101,102]. Quantitatively, we see that …”

“…The manifestations of PNC in atoms and chiral molecules have been reviewed many times with the exception of SFG [98,99,100]. Exactly like atomic optical rotation, there is atomic SFG.…”

Asymmetric Autocatalysis and Its Implications for the Origin of Homochirality

“…However, as Mislow (13) points out in a particularly lucid recent review on absolute asymmetric synthesis, it has long been known, if not generally recognized, that at least some degree of ee may be achieved without chiral intervention in such syntheses. The fact is that enantiomerically enriched products are bound to be formed from achiral precursors, merely as a result of statistical fluctuations (14)(15)(16)(17)(18). The historical development of these ideas is detailed by Mislow (13).…”

Bicircular High-Harmonic Spectroscopy Reveals Dynamical Symmetries of Atoms and Molecules

“…Symmetry breaking is the source of a myriad of important physical effects. Famous examples include parity violation through the weak nuclear force, which results in energy differences between enantiomers of a chiral molecule [4], and the Jahn-Teller effect, which is the key to understanding the structure and dynamics of many molecules, transition-metal complexes, and solids [5,6].…”