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The physical and chemical properties of three new liquid crystalline derivatives, based on an azomethine core with low-temperature mesophase—namely (4-methoxybenzylideneamino) phenyl palmitate (I), (4-methoxybenzylideneamino) phenyl oleate (II), and (4-methoxybenzylideneamino) phenyl linoleate (III)—were prepared and physically examined using experimental methodologies. Elemental analysis, FT-IR, and NMR spectroscopy were used to confirm their molecular structure. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) were used to investigate their mesomorphic activity. The results revealed that compound (I) is monotropic smectogenic, possessing the smectic A mesophase, whereas the other two analogues were shown to possess the SmA phase enantiotropically. Two of the saturated and unsaturated prepared derivatives (namely I and II) were used to construct their phase diagram. The eutectic composition of the mixture examined showed a slight enhancement of the stability of the smectic A phase. Polymorphic phases were produced at the eutectic composition of the binary phase diagram of the derivative II with the 4-n-dodecyloxy benzoic acid component.

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New three-ring ester/azomethine homologues series, (E)-4-((4-hydroxybenzylidene)amino)phenyl 4-(alkoxy)benzoate In, were prepared and their properties were investigated experimentally and theoretically. FT-IR, NMR, and elemental analyses were used to confirm the chemical structures of the synthesized compounds. The mesomorphic activities of the planned homologues were evaluated using differential scanning calorimetry (DSC) and polarized optical microscopy. All of the homologous examined were found to have non-mesomorphic properties. Theoretical calculations using the density functional theory (DFT) were used to validate the experimental data and determine the most stable conformation of the synthesized compounds. All calculated conformers’ thermal properties, dipole moments, and polarizability were discussed. The results show that the terminal alkoxy chain length affects the thermal parameters of the conformers. The correlations between these parameters’ values and the conformer type were demonstrated. The base component was expected to be in two conformers according to the orientation of the N atom of imine-linkage. DFT calculations revealed the more probable of the two possible conformers, and the incorporation of the alkoxy terminal chain in one position affect its geometrical and mesomerphic characteristics.

This work intended to enhance the unique and outstanding properties of lanthanum by synthesizing its nanocomposite. A lanthanum-based nanocomposite was prepared by a simple and cost-effective “co-precipitation” method. Lanthanum nitrate (La (NO3)3) and zinc nitrate (Zn (NO3)2) were used as precursors. The lanthanum/zinc oxide nano composite formed was then calcined at 450 °C for 4 h in order to obtain a fine powder with size in the nano range of 1–100 nm. Characterization of the prepared catalyst was done by ultraviolet/visible spectroscopy, Fourier transform infrared spectroscopy, and photoluminescence. Crystallinity and morphology were found by X-ray diffraction and scanning electron microscopy. The synthesized nanocomposite material was also tested for heterogeneous catalytic applications of 4-nitrophenol (4-NP) reduction into 4-aminophenol (4-AP). It was found to be successful in complete reduction of 4-NP with enhanced catalytic performance.

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