Crystal Structures and Triboluminescence Based on Trifluoromethyl and Pentafluorosulfanyl Substituted Asymmetric N-Phenyl Imide Compounds

A series of asymmetric N-phenyl imides with trifluoromethyl and pentafluorosulfanyl substituents at the terminal phenyl position have been prepared. They are colorless both in solution and the solid state, and they show blue emission in the solid state. X-ray crystal structure analysis of trifluoromethyl and pentafluorosulfanyl substituted derivatives revealed highly ordered noncentrosymmetric molecular arrangements with large net-dipole moments related to the piezoelectric behavior. XRD measurements of the powders afforded intense sharp reflection peaks, indicating formation of the lamellar ordering. By grinding with a spatula, their solids showed vivid blue triboluminescence.