Experimental
and Computational Growth Morphology of Two Polymorphs of a Yellow
Isoxazolone Dye
M. A. Deij, E. Aret, S. X. M. Boerrigter, L. van Meervelt, G.
Deroover,# H. Meekes,* and E. Vlieg
Abstract:
We report on the crystal structures and the experimentally found and
the computationally predicted growth morphologies of two polymorphs of
a yellow isoxazolone dye. The stable polymorph I has a blocklike habit,
and the metastable polymorph II grows as fine needles, nucleating only
by heterogeneous or contact nucleation. The habits of both polymorphs
depend on the supersaturation during growth. The experimental
observations are compared with predictions of the attachment energy
model and kinetic Monte Carlo lattice simulations in which the growth
is modeled as an 'atomistic process', governed by surface energetics.
These Monte Carlo simulations correctly predict the shape and the
dependence on supersaturation of the crystal morphology for both
polymorphs: for polymorph I, a strong dependence on supersaturation is
found from the simulations. For polymorph II, the order of
morphological importance is reproduced correctly, as well as the
needlelike morphology.