Synthesis and characterization of new mesogenic esters derived from 1,2,4-oxadiazole and study the effect of alkoxy chain length in their liquid crystalline properties

被引:25
作者
Ali, Ghassan Q. [1 ]
Tomi, Ivan Hameed R. [1 ]
机构
[1] Univ Al Mustansiriyah, Dept Chem, Coll Sci, Baghdad, Iraq
关键词
1,2,4-Oxadiazole; mesomorphic; liquid crystalline; ester mesogens; MESOMORPHIC BEHAVIOR; PYRIDYL-1,2,4-OXADIAZOLE DERIVATIVES; 3,5-DISUBSTITUTED 1,2,4-OXADIAZOLES; X-RAY; 1,3,4-OXADIAZOLE; DIMERS; ACID; OXADIAZOLE; MOIETY; PHASE;
D O I
10.1080/02678292.2017.1338767
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
In this study, a new series of non-symmetrically 3,5-disubstituted of 1,2,4-oxadiazole derivatives, 4-[5-(4-methylphenyl)-1,2,4-oxadiazol-3-yl]-phenyl-4-alkoxybenzoate (G(1)-G(11)), which containing ether and ester linkages in the same molecule, is synthesized using different synthetic procedures and their structures are confirmed by several spectroscopic techniques (FT-IR and H-1 nuclear magnetic resonance). The mesomorphic properties of these compounds are studied by differential scanning calorimetry (DSC) and polarized optical microscopy (POM); all these derivatives exhibited as mesogens and displayed an enantiotropic liquid crystal with nematic texture, the nematogenic phase of these materials was appeared in wide temperature ranges on heating and cooling cycles that were observed by POM and DSC. The influence of 1,2,4-oxadiazole ring and the elongation of alkyl chain in the mesomorphic properties of this series were investigated. The mesogenic behaviour of this series was compared with the compounds possessing a somewhat similar structure. [GRAPHICS] .
引用
收藏
页码:421 / 430
页数:10
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