The parity-violating energy difference between enantiomeric reactions

Abstract

The parity-violating weak neutral current perturbation of the electronic energy has been calculated, using ab initio methods, along the reaction path for the formation of L-α-amino-propionitrile by the nucleophilic addition of a cyanide anion to an ethyl-iminium cation. The WNC energy shift for this prebiotic reaction, leading to a possible precursor of the amino acid alanine, is found to favour the existence of the natural L-enantiomer in preference to the unnatural mirror-image D-enantiomer under equilibrium conditions.