M. Kitamura, T. Hara
Mar 20, 2007
Citations
0
Influential Citations
5
Citations
Journal
Crystal Growth & Design
Abstract
The ffect of molecular structure on polymorphic crystallization was investigated by the rapid cooling method in ethanol solutions using BPT methyl ester (Me-est, methyl 2-(3-cyano-4-(2-methylpropoxy)-phenyl)-4-methyl-thiazole-5-carboxylate), BPT propyl ester (Pr-est, propyl 2-(3-cyano-4-(2-methylpropoxy)-phenyl)-4-methyl-thiazole-5-carboxylate), and BPT isobutyl ester (i-But-est, 2-methylpropyl 2-(3- cyano-4-(2-methylpropoxy)-phenyl)-4-methyl-thiazole-5-carboxylate). The crystallization of Me-est resulted in only one crystal form at every initial concentration. In the crystallization of Pr-est and i-But-est at a supersaturation ratio lower than 1.85, the stable B form directly crystallized. However, at higher supersaturation, the metastable A form first appeared, and the subsequent transformation to the B form occurred after that (Ostwald step rule is established). The solution-mediated transformation rate appeared to be faster for i-But-est than for Pr-est. The Me-est crystal is constructed by stacking t...