عنوان المقالة:Study the effect of different terminal substituents on the liquid crystalline properties of the new synthesized 1,2,4-oxadiazole derivatives Study the effect of different terminal substituents on the liquid crystalline properties of the new synthesized 1,2,4-oxadiazole derivatives
ABSTRACT
A new series of 4-(5-(p-tolyl)-1,2,4-oxadiazol-3-yl)phenyl substitutedbenzoate, (IIIx) incorporating
ester linkage with various substituted groups in various positions on the phenyl ring were synthesized
and investigated by FT-IR and 1
H-NMR spectroscopies in addition to the CHN analysis, their
mesophase behaviors were examined by optical polarized microscopy (OPM) and differential scanning
calorimetry (DSC). Only the derivatives that have terminal substituents in the para position
showed liquid crystalline properties with a wide range of nematic phase and various textures
(Schlieren, thread-like, marble and nematic droplets) both in heating and/or cooling runs. The relationship
between nature and position of the substituent groups, central core and ester linkage of
these derivatives with their liquid crystalline properties were studied and the results were analyzed,
discussed and compared with other mesogenic materials have a chemical composition similar
to the compounds prepared in this study.
غسان قيس علي | Ghassan Qays Ali | 5050