Preferential Cocrystallization among Distyrylbenzene Derivatives

A combination of powder and single-crystal X-ray diffraction techniques were used to probe the generality of phenyl−perfluorophenyl stacking among a small library of 1,4-distyrylbenzene derivatives. The specific derivatives in the present study are 1,4-bis-(4-dimethylaminostyryl)benzene ( DMADSB ), 1,4-distyrylbenzene ( DSB ), 1,4-di(1-cyano-2-phenylethenyl)benzene( CNDSB ), 1,4-di(1-cyano-2-(4-methylphenyl)ethenyl)benzene ( MeCNDSB ) 1,4-bis(styryl)-2,5-difluorobenzene ( 2F c ), 1,4-bis(4-fluorostyryl)-2,5-difluorobenzene ( 2F c 2F t ), 1,4-bis(pentaflourostyryl)benzene ( 10F t ), and 1,4-bis(pentafluorostyryl)-2,5-difluorobenzene ( 2F c 10F t ). Electrostatic distribution diagrams aid in assessing the likelihood of success in pair formation. Powder diffraction provides a means to determine both positive and negative results for binary phase formation. Four new structures are presented and discussed including ( DSB / 2F c 10F t ), ( DMADSB / 2F c 10F t ), ( CNDSB / 2F c 10F t ), and ( MeCNDSB / 2F c 10F t ). Single-crystal diffraction work confirms that the resulting lattices contain alternating layers of fluorinated and unfluorinated DSB derivatives arranged in a cofacial fashion with multiple H···F interactions between stacks. Differential scanning calorimetry is reported on ( DSB / 2F c 10F t ), ( CNDSB / 2F c 10F t ), ( MeCNDSB / 2F c 10F t ), and their components.