Synthesis, Optical Characterizations and Solar Energy Applications of New Schiff Base Materials

Abstract

A new set of laterally OCH3-substituted photoactive liquid crystalline analogues, 4-hexyloxy phenyl- imino-4ʹ-(3-methoxyphenyl)-4ʹ’-alkoxybenzoates, were synthesized and investigated for their mesomorphic behavior. The prepared set constitutes five analogues that differ from each other by the terminally attached compact polar group. Characterization of the synthesized derivatives is conducted using differential scanning calorimetry (DSC), polarized optical microscopy (POM), and UV-spectroscopy. Molecular structures were elucidated by elemental analyses, FT-IR and NMR spectroscopy. DSC and POM investigations indicated that all the prepared derivatives are monomorphic possessing the nematic (N) phase, except for the unsubstituted derivative that is nonmesomorphic. On the other side, the photophysical study and the optical spectra measurements confirm the photoactivity of the present compounds under UV/visible irradiation. The measured optical spectra showed impressive enhancement in the optical absorption and reduction in the optical bandgap from 3.63 to 3.0 eV depending on the terminal group. From the study of the DC electric properties, the lowest resistance, 106.5 GΩ at scan rate 0.1 V/s, was observed for the I6d film with Cl terminal, which decreased to 49.5 GΩ by increasing the scan rate to 0.5 V/s. Moreover, the electrical conductance is decreased from 9.39 pS to 1.35 pS at scan rate 0.1 V/s by changing the terminal group from Cl to F. The enhanced optical absorption and the reduced energy gap make the optimized samples suitable material for solar energy applications.

A Review on the Antimicrobial Activity of Schiff Bases: Data Collection and Recent Studies

“…Additionally, the use of SBs as catalysts in fixation of CO 2 to mitigate its accumulation in the atmosphere has been widely described [ 11 ]. SBs have also been studied in the carbohydrate research field in relation to Amadori products [ 12 ] and in material chemistry for applications in photoactive solar energy [ 13 , 14 ] and vitrimers [ 15 ]. Moreover, chemical reactions involving SBs may be found in sensors used to analyze illicit drugs and determine analytes in seized samples [ 16 ].…”

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

“…Because of their unique mesomorphic capabilities, azomethine/ester homologous series of liquid crystals (LCs) have been studied extensively to determine the relationship between chemical structure and mesomorphic properties [ 21 , 22 , 23 , 24 , 25 ]. In general, an organic compound’s mesophase stability and temperature ranges are determined significantly by its molecular shape, with even little changes in molecular geometry resulting in significant changes in mesomorphic behavior [ 26 ].…”

Induced Nematic Phase of New Synthesized Laterally Fluorinated Azo/Ester Derivatives

“…They can also produce photoactive mesomorphic materials, whereby they can easily undergo photo-induced trans/cis isomerization. Among many mesogenic linkages, azobenzenes are the most widely documented [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”