Synthesis, characterization and study of Mesomorphic behavior of new bent and liner core compounds containing heterocyclic

Abstract EN

We described herein the synthesized and characterized of new bent and liner core compounds containing thiazolidin-4-one ring[XI-XIII] and [XTV-XVl] respectively.

These compounds synthesized by sequence reactions starting from reaction resorcinol or hydroquinone with chloracetyl chloride to yield confounds [I] and [II] .then the later compounds reactant with 4-hydroxybenzylaldehyde to product dialdehyde compounds [HI] and [IV] .The Schifif bases compounds[V-VII] and [\TD-X] synthesized from reaction the compound [III] or [IV] with different aromatic amines, while the bent and liner core mesogens containing thiazolidin-4-one ring [XI-XIII] and [XTV-XVI] synthesized from reaction Schifif bases conipounds[V-VII] or [YIII-X] with thioglycolic acid.

In addition estrfecation of cinnamic acid with methanol to yield ester compound[XVn]\vhich was converted to their acid hydrazid[XVffl] and the acid hydrazid reacted with glysine in phosphorous oxychloride to yield (5-styiyi-l .3.4-oxadiazol-2-yl) methanamine [XIX].

Then reactant thel.3.4-oxadiazol compound[XIX] with dialdehyde confound [III] or [IV] to product new Schifif bases compounds [XX] and [XXI] .

afterword added thioglycolic acid to give new thiazolidin-one derivatives [XXII] and [XXIII].

respectively.

The synthesized compounds were characterized by melting points .

FTIR ^HNMR and mass spectroscopy (of some of them).

The liquid crystalline properties were studied by hot stage polarized optical microscopy (POM) and differential scanning calorimetry(DSC).All the Schiff bases compounds [V-X] showred liquid crystals phases while thiazolidin-4-one derivatives [XI-XIII].

[XTV-XVI] and [XXIII] didn't show any liquid crystals properties except the compound [XXII] showed enantiotropic nematic phase.