Solubility measurement of a metastable achiral crystal of sodium chlorate in solution growth

• Achiral crystals of NaClO3 were grown from solution by antisolvent crystallization.
• We assessed supersaturation attained by antisolvent addition vs. volume fraction.
• Solubility of the achiral crystal grown from solution was measured at 10 and 23 °C.
• The solubility was determined to be 1.6 times higher than that of chiral crystal.
• Accuracy of the solubility was assessed based on kinetics of polymorphic transition.

The solubility of the metastable achiral monoclinic phase in NaClO3 crystallization from an aqueous solution, which appears prior to the nucleation of chiral crystals, was successfully measured in the range from 10 °C to 23 °C. Antisolvent crystallization method was used to obtain metastable crystals for the measurement. The solubility was determined to be about 1.6 times higher than that of the chiral stable cubic phase by observing growth or dissolution of the crystal in aqueous solution at the temperature and concentration of which is predetermined.