Prediction of the Growth Habit of 7-Amino-4,6-dinitrobenzofuroxan Mediated by Cosolvents

Abstract

The morphology of 7-amino-4,6-dinitrobenzofuroxan (ADNBF) recrystallized from cosolvents was shown to evolve systematically from rod to plate as the mixing ratio of cosolvents (N-methyl-2-pyrrolidone (NMP)/acetonitrile, NMP/chloroacetone, and NMP/methanol) varied from 1:1 to 1:4. In an attempt to explain the cosolvent effect on the shape evolution of ADNBF crystals, the characteristics of the ADNBF crystal surface were investigated by molecular modeling techniques. The morphology of ADNBF recrystallized from cosolvents was predicted by the modified attachment energy model with terms of binding site density, as well as interaction energy and fraction of cosolvents. Comparison of predicted morphologies with experimental results shows that the higher binding site density with solvents in the (001) surface of ADNBF is responsible for the strong inhibition of growth on the (001) plane even though interaction of individual solvent molecules on this surface is weaker than that on the other planes.