Antonietta Di Pumpo -
Hydrogen bonding structure and polymorphism in agrochemicals
The term polymorphism indicates the ability of a substance to crystallise in different crystal structures, which show different physical properties, such as colour, solubility, density, melting point and electric or thermal conductivity.
Polymorphism of crystals, crystal habit and crystal growth are important factors that must be controlled for any commercial crystallization process. Pharmaceuticals and agrochemicals are two of the most industrially-
An example of how the polymorphic behaviour affects the commercial use and application of an agrochemical is the fungicide Cyprodinil. This fungicide exists in two forms, modifications A and B, which differ from one another because of a different hydrogen bonding networks. Upon storage, the metastable form B undergoes a slow conversion to the other form, causing particle aggregation, which then blocks the nozzles of delivery equipment, reducing the ability to spray the compound effectively onto crops. My research focuses on the extensive characterization of the hydrogen bonds responsible for the different crystal packing among polymorphs. Such knowledge represents the most valuable tool for the stabilization of a preferred polymorph and for the design of multi-
Weller, M. T., Weber, O. J., Henry, P. F., Di Pumpo, A. M. and Hansen, T. C., Complete structure and cation orientation in the perovskite photovoltaic methylammonium lead iodide between 100 and 352 K. Chemical Communications, 51 (20), 4180-