The rôle of powder diffraction in establishing structure–property relationships for crystalline solids: a new structural assignment of the photoreactive and photostable phases of p-formyl-trans-cinnamic acid

Abstract

It has been reported previously that the photoreactive β phase of p-formyl-trans-cinnamic acid represents an exception to the well-established correlation between structural and photochemical properties of crystalline trans-cinnamic acid derivatives. However, it is shown in this paper that the crystal structure reported previously to be the β phase of p-formyl-trans-cinnamic acid is actually the photostable γ phase. In a wider context, the work reported here highlights the necessity of carrying out powder diffraction investigations in the determination of structure–property relationships for crystalline solids.