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-dimethyl-aminostyryl)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.