Izvorni znanstveni članak

https://doi.org/10.5562/cca2150

Symmetric Bent-core Liquid Crystals of Some Schiff Bases Containing Azo Linkage

Catalina Ionica Ciobanu ; Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, “Gheorghe Asachi” Technical University of Iasi, Bd. D. Mangeron 71A, 700050 Iasi, Romania
Irina Carlescu ; Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, “Gheorghe Asachi” Technical University of Iasi, Bd. D. Mangeron 71A, 700050 Iasi, Romania
Gabriela Lisa ; Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, “Gheorghe Asachi” Technical University of Iasi, Bd. D. Mangeron 71A, 700050 Iasi, Romania
Dan Scutaru ; Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection, “Gheorghe Asachi” Technical University of Iasi, Bd. D. Mangeron 71A, 700050 Iasi, Romania

Sažetak

The paper presents the synthesis and liquid crystalline properties of some new symmetric bent-core liquid crystals containing a 1,3-dihydroxybenzene central core disubstituted with mesogenic units consisting of three aromatic rings connected through esteric, azomethinic and azo groups. The wings are ended with terminal acyloxy or alkyloxy chains containing 6 to 10 carbon atoms. Compounds were ob¬tained by the condensation reactions between some 4-((4-alcanoyloxyphenyl)azo)benzaldehydes or 4-((4-alkyloxyphenyl)azo)benzaldehydes with the 1,3-phenylene bis(4-aminobenzoate) core. The new synthe-sized compounds were characterized from structural point of view (1H NMR, 13C NMR, MS spectrosco¬py) and liquid crystalline properties (polarizing optical microscopy and differential scanning calorimetry). All the banana shaped compounds presented enantiotropic liquid crystalline properties, with a wide-ranging stability of mesophases both on heating and cooling cycles. The synthesized compounds present¬ed a good thermal stability in the existence range of the mesophases as evidenced by thermogravimetric studies. (doi: 10.5562/cca2150)

Ključne riječi

Schiff Bases; symmetric bent-core compounds; mesomorphic properties; azo linkage

Hrčak ID:

122274

URI

https://hrcak.srce.hr/122274

Datum izdavanja:

30.4.2014.

Posjeta: 2.323 *