X-ray diffraction and microscopy study of supramolecular networks of amido functionalized compounds

Abstract

Crystalline amido functionalized organic compounds have been investigated towards the forming of solvates, halogenides and their reactivity towards various metal salts at different temperatures and under variable recrystallization conditions. Crystal structure determination, temperature-dependant X-ray powder diffraction as well as hot-stage microscopy experiments have been carried out successfully and revealed new aspects for a crystal engineering of isotypical but not isomorphous co-crystals or supramolecular compounds. Even though the crystal structure of co-crystals of melamine and EDTA (ethylenediaminetetracetic acid) contains water molecules, the two components form a solvent-less stable supramolecular network. In contrast to this, the inclusion of different solvents into the structure of 1,4-diaminocyclohexane chloride and 1,4-piperazine chloride (see Fig.) causes significant structural changes as demonstrated by hot-stage microscopy and X-ray diffraction experiments at various temperatures. We investigate the reasons for these structural changes due to solvent inclusion.