title: Effect of beta radiation on the crystallization of sodium chlorate from water: a new type of asymmetric synthesis.
abstract: Sodium chlorate is an achiral molecule that crystallizes from water in the chiral space group P2(1)3. In the absence of chiral perturbations, a random distribution of (+) and (-) crystals is obtained. Kondepudi(2) has shown that constantly stirring an evaporating NaClO(3) solution gives mostly either (+) or (-) crystals. Repeating this experiment many times gives equal numbers of (+) and (-) sets of crystals. Herein we report that when evaporating aqueous NaClO(3) is subjected to beta particles from an Sr-90 source, an asymmetric distribution of (+) and (-) crystals favoring the (+) crystals is obtained. The beta particles are energetic polarized electrons that are approximately 80% of left-handed helicity. By a poorly understood mechanism, the spin polarized electrons produce chiral nucleating sites that favor formation of the (+)-NaClO(3) crystals. Exposure of the evaporating solution instead to energetic positrons from an Na-22 source yields mainly (-)-NaClO(3) crystals. Polarized positrons are of predominantly right-handed helicity. One may conclude that the chirality of the radiation is correlated with the chirality of the crystals being generated.
authors.affiliation: Department of Physics, University of Tennessee, Knoxville, Tennessee 37996-1600, USA.
authors.forename: S
authors.initials: S
authors.lastname: Mahurin
authors.forename: M
authors.initials: M
authors.lastname: McGinnis
authors.forename: J S
authors.initials: JS
authors.lastname: Bogard
authors.forename: L D
authors.initials: LD
authors.lastname: Hulett
authors.forename: R M
authors.initials: RM
authors.lastname: Pagni
authors.forename: R N
authors.initials: RN
authors.lastname: Compton