Mechanism of Crystallization of Perylene diimides in Aqueous Media

Classical nucleation theory (CNT) has dominated description of crystalline nucleation and growth. While CNT offers valuable insight into processes taking place during crystallization, it has substantial shortcomings. Alternative nucleation mechanisms have been proposed mending CNT’s shortcomings¹^,².

In this contribution, we present experimental monitoring of the entire crystallization process of a representative simple aromatic compound - perylene diimide. Our study correlates spectroscopic and structural measurements, allowing us to identify key stages in crystal evolution. Our findings support a two-step nucleation mechanism rather than one step nucleation as described by CNT. Our studies provide fundamental insights into the formation of crystalline phases, and suggest strategies to control crystallization of organic molecules.

References

(1) Vekilov, P. G. Nucleation. Cryst. Growth Des. 2010, 10, 5007–5019.

(2) De Yoreo, J. J.; Gilbert, P. U. P. a.; Sommerdijk, N. a. J. M.; Penn, R. L.; Whitelam, S.; Joester, D.; Zhang, H.; Rimer, J. D.; Navrotsky, A.; Banfield, J. F.; Wallace, a. F.; Michel, F. M.; Meldrum, F. C.; Colfen, H.; Dove, P. M. Crystallization by particle attachment in synthetic, biogenic, and geologic environments. Science. 2015, 349, aaa6760.