Experimental and Theoretical Investigations of Three-Ring Ester/Azomethine Materials

Fowzia S Alamro; Nada S Al-Kadhi; Sobhi M Gomha; Saheed A Popoola; Muna S Khushaim; Omaima A Alhaddad; Hoda A Ahmed

doi:10.3390/ma15062312

Experimental and Theoretical Investigations of Three-Ring Ester/Azomethine Materials

Materials (Basel). 2022 Mar 21;15(6):2312. doi: 10.3390/ma15062312.

Authors

Fowzia S Alamro¹, Nada S Al-Kadhi¹, Sobhi M Gomha^{2

3}, Saheed A Popoola², Muna S Khushaim^{4

5}, Omaima A Alhaddad⁶, Hoda A Ahmed^{3

7}

Affiliations

¹ Department of Chemistry, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia.
² Chemistry Department, Faculty of Science, Islamic University of Madinah, Madinah 42351, Saudi Arabia.
³ Department of Chemistry, Faculty of Science, Cairo University, Cairo 12613, Egypt.
⁴ Department of Physics, Faculty of Science, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi Arabia.
⁵ Nanotechonolgy Center, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi Arabia.
⁶ Chemistry Department, College of Sciences, Taibah University, Madina Monawara 30002, Saudi Arabia.
⁷ Chemistry Department, College of Sciences, Taibah University, Yanbu 30799, Saudi Arabia.

Abstract

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.

Keywords: DFT; conformational analysis; imine derivatives; mesomorphic properties; thermal parameters.