Synthesis and crystal engineering of fluorinated stilbenes

CrystEngComm Pub Date: 2006-02-20 DOI: 10.1039/B517032J

Abstract

Three new polyfluorinated (E)-4-(4-bromostyryl)benzonitriles were obtained by the Horner–Wadsworth–Emmons approach to investigate intermolecular interactions in the crystalline state and the formation of co-crystals. Electrostatic surface potentials and dipole moments were calculated by ab initio methods. Three types of main intermolecular interactions were addressed to be used as a driving force to form polar co-crystals: CN?Br interactions lead to chain formation. Stacking of F-aromatic and H-aromatic rings is present. C–F?H and C–F?F interactions were identified, which are weak driving forces to align molecules sidewise. Crystal structures of the three stilbenes are centric. By formation of solid solutions [(E)-4-(4-bromostyryl)-2,3,5,6-tetrafluorobenzonitrile]x·[(E)-4-(4-bromo-2,3,5,6-tetrafluorostyryl)benzonitrile]1?x, polar properties were observed. In the case of (E)-4-(4-bromostyryl)benzonitrile·(E)-4-(4-bromo-2,3,5,6-tetrafluorostyryl)-2,3,5,6-tetrafluorobenzonitrile, a non-polar 1 ∶ 1 ordered structure is formed.

Graphical abstract: Synthesis and crystal engineering of fluorinated stilbenes
Recommended Literature