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Effect of beta radiation on the crystallization of sodium chlorate from water: A new type of asymmetric synthesis
Author(s) -
Mahurin Shan,
McGinnis Michael,
Bogard J.S.,
Hulett L.D.,
Pagni Richard M.,
Compton Robert N.
Publication year - 2001
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.10007
Subject(s) - sodium chlorate , chemistry , chirality (physics) , crystallization , aqueous solution , electron , crystallography , helicity , crystal (programming language) , chemical physics , inorganic chemistry , physics , organic chemistry , chiral symmetry breaking , particle physics , quantum mechanics , computer science , nambu–jona lasinio model , programming language , quark
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. Chirality 13:636–640, 2001. © 2001 Wiley‐Liss, Inc.