2804-78-6Relevant academic research and scientific papers
Crystal Structures of the Room-Temperature Phase of 4,4''-Difluoro-p-terphenyl and 4,4'''-Difluoro-p-quaterphenyl
Saitoh, Hideki,Saito, Kazuya,Yamamura, Yasuhisa,Matsuyama, Haruo,Kikuchi, Koichi,et al.
, p. 2847 - 2853 (2007/10/02)
4,4''-Difluoro-p-terphenyl and 4,4'''-difluoro-p-quaterphenyl were synthesized and their crystal structures were determined at room temperature.These are isostructural to p-terphenyl and p-quaterphenyl, respectively.Some "disorder" in the inner benzene ring orientation was detected and resolved by the split-atom method.A rigid-body librational analysis of each benzene ring around the long molecular axis was performed.A rough estimate of the barrier height of the planar conformation for 4,4''-difluoro-p-terphenyl was obtained as being about 1 kJ mol-1.The results are compared with the properties of p-terphenyl and p-quaterphenyl, and the effect of fluorine-substitution on the molecular properties is discussed in relation to the low-temperature phase transitions.
