Solubility-Hardness Correlation in Molecular Crystals: Curcumin and Sulfathiazole Polymorphs
2014; American Chemical Society; Volume: 14; Issue: 6 Linguagem: Inglês
10.1021/cg500305n
ISSN1528-7505
AutoresManish Kumar Mishra, Palash Sanphui, Upadrasta Ramamurty, Gautam R. Desiraju,
Tópico(s)Nonlinear Optical Materials Research
ResumoCurcumin and sulfathiazole exist as three and five polymorphs, respectively. We correlate solubility and mechanical properties in these polymorphic systems. It is seen that hardness (H) is inversely proportional to the solubility of a polymorph. H of the polymorphs is explained on the basis of slip planes in the crystal structure, the Schmid factor (m), and the relative orientation of molecules with respect to the nanoindenter direction. Effectively, H is a useful parameter (compared to melting point, Tm, and density, ρ) that correlates well with the solubility of a polymorph. Such a correlation is helpful in systems like curcumin and sulfathiazole in which the Gibbs free energy of the polymorphs are close to one another. To summarize, a softer polymorph is more soluble.
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