Recrystallization solvent-dependent elastic/plastic flexibility of an n -dodecyl-substituted tetrachlorophthalimide.

A long alkyl-chained organic molecule, 4,5,6,7-tetrachloro-2-dodecylisoindoline-1,3-dione (1), was crystallized into needle-like crystals in dichloromethane (1DCM) or plate-like ones in tetrahydrofuran (1THF) depending on the recrystallisation solvent. X-ray crystallography analyses revealed the alkyl chains of the molecules, in which they were assembled differently, with the former responding flexibly bendable and elastic deformation, and the later being a permanent plastic one by external mechanical stress. The elastic modulus ( E ) and hardness ( H ) indicating both compliant and soft nature, reflecting their weak interaction in crystals, were quantified from the nano-indentation test.