Polymorphic behavior of a yellow isoxazolone dye

摘要

The crystal growth of a monotropic polymorphic system of a yellow isoxazolone dye has been studied.One of the two metastable polymorphs grows into a needle-shaped morphology;the stable form is rhombic.The metastable third polymorph grows only from the melt and has a solid-solid phase transition to the needle-shaped form within hours at any temperature below the melting point.The polymorphic phase diagram has been determined for a wide range of concentrations in three solvents.