synthesis, characterization, and studying of (thermal, spectral and physical) properties of new schiff base monomers and liquid crystal compounds from ampicillin

This work presents syntheses of six new schiff base compoundsfrom ampicillin, p-hydroxyl benzaldehyde reacted with(pentanol, hexanol, and heptanol) to produce (4-pentloxy, 4-hexaloxy, and 4- hepteloxy) benzaldehyde, and compounds (phydroxy,p- chloro, p-nitro) benzaldehyde used to produce schiffbase compounds. the prepared compounds have been identifiedusing (ft-ir and h1-nmr) techniques. the microscopic phaseswere determined using a polarized light microscope (pom), andthe thermal properties of the transition temperatures for thesecompounds were measured using a differential scanningcalorimeter (dsc). all compounds' melting points, colors, andyields were detected. then the liquid crystalline behavior wasstudied, which showed that the compounds gave liquid crystallineproperties and determined whether the compounds gave thenematic phase or the smectic phase.