Crystalline packings of diketoarylhydrazones controlled by a methyl for trifluoromethyl structural change

Abstract

Three new hydrazone compounds having a p-iodoaryl and diketohydrazone molecular skeleton in common but feature a gradual replacement of the two methyl groups for trifluoromethyl terminal ones were prepared and comparatively studied with regard to their crystal structures. A quantum chemical calculation of the single trifluoromethyl modified compound was undertaken to decide on the hydrogen bonded ring site. While the molecular structures of the compounds remain rather unimpaired by the fluorine substitution, their crystalline packings are markedly affected, showing a distinct supramolecular control in the crystal lattices.