Demonstration of the parity-violating energy difference between enantiomers.

Racemic mixtures of (+) and (-) sodium potassium tartrate, tris(1, 2-ethanediamine)cobalt(III), and tris(1,2-ethanediamine)iridium(III) molecules were crystallized, and the optical activities of the resulting crystalline materials, dissolved in water, were carefully measured to study the influence of the parity-violating energy difference in the crystallization process. Although no effect was found in the case of tartrate, enantiomeric excess appeared in the crystallization of the cobalt and iridium complexes. These investigations, performed in our laboratory, demonstrated the contribution of the parity-violating neutral weak current to the forces acting in molecules.