Crystal Engineering


Photo- and thermochromism

Chromotropism is a reversible color change linked to structural (or environmental changes). A lot of attention has been paid to those compounds that change color due to external stimuli such as temperature (thermochromism), irradiation (photochromism) or solvent exchange (solvatochromism). Most compounds are responsive in solution, as the response often implies strong structural changes. We try to render compounds chromotropic at the solid state, by altering the nature of the solid state.

Amongst others we work on anils, which are known to be thermo- as well as photochromic.


Control of powder quality

Final powder of a pharmaceutically active compound can present unwanted properties (flowability, hygroscopicity, particle size, ...). We aim at controlling these properties by crystal engineering. In this context, we tackled the hygroscopicity of lactic acid through co-crystallization. Lactic acid can be co-crystallized with D-tryptophane removing its deliquescence.