Effect of the Relative Orientation of the Two Fluoro-Substituents on the Mesophase Behavior of Phenylazophenyl Benzoates
作者:M. M. Naoum、A. A. Fahmi、H. A. Ahmed
DOI:10.1080/10426507.2012.660867
日期:2012.8.22
Four novel types of laterally di-fluoro substituted 4-(2'-(or 3'-) fluoro phenylazo)-2-(or 3-) fluoro phenyl-4 ''-alkoxybenzoates were prepared and investigated for their mesophase behavior. In order to deduce the most probable conformation for each of the positional isomers investigated, the dipole moments for each of the four novel types have been determined experimentally in benzene at 30 degrees C and compared with those theoretically calculated using molecular modeling program. Probable conformations deduced were found to vary according to the relative orientations of the two fluorine atoms. The results were used to correlate the mesophase behavior, in pure and mixed derivatives, with the conformation deduced for each series. The study aims to investigate the effect of the spatial orientation of the two lateral fluoro-substituents on the mesomorphic properties in their pure and mixed states.