First mesomorphic and DFT characterizations for 3- (or 4-) n -alkanoyloxy benzoic acids and their optical applications.

Autor:	El-Atawy MA; Chemistry Department, Faculty of Science, Alexandria University, P.O. Box 426, Ibrahemia, Alexandria 21321, Egypt.; Chemistry Department, College of Sciences, Taibah University, Yanbu 30799, Saudi Arabia., Khan MT; Department of Physics, Faculty of Science, Islamic University of Madinah, Al-Madinah Al-Munawwarah 42351, Saudi Arabia., Popoola SA; Chemistry Department, Faculty of Science, Islamic University of Madinah, Madinah 42351, Saudi Arabia., Khushaim MS; Department of Physics, Faculty of Science, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi Arabia.; Strategic Research Labs, Taibah University, P.O. Box 30002, Al-Madina 41447, Saudi Arabia., Jaremko M; Biological and Environmental Sciences & Engineering Division (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia., Emwas AH; Core Labs., King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia., Alamro FS; Department of Chemistry, College of Science, Princess Nourah Bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia., Naoum MM; Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt., Ahmed HA; Department of Chemistry, Faculty of Science, Cairo University, Giza 12613, Egypt.
Jazyk:	angličtina
Zdroj:	Heliyon [Heliyon] 2023 Aug 24; Vol. 9 (9), pp. e19384. Date of Electronic Publication: 2023 Aug 24 (Print Publication: 2023).
DOI:	10.1016/j.heliyon.2023.e19384
Abstrakt:	New liquid crystalline hydrogen bonded 3- (or 4)- n -alkanoyloxy benzoic acids were synthesized and probed theoretically and experimentally. The molecular structures of these compounds were elucidated by proton NMR, carbon-13 NMR and elemental analyses. Differential scanning calorimetry (DSC) was used to investigate the thermal and mesomorphic properties of all the symmetrical dimers that bearing identical alkanoyloxy chains. Moreover, polarized optical microscopy (POM) was used to determine their mesophases. The findings show that all the designed symmetrical dimers exhibit the smectic mesophase with relative thermal stability that depends on the length of their terminal side chain. Additionally, the experimental findings of the mesomorphic behavior are further supported by DFT calculations. The alkanoyloxy benzoic acid para-derivatives ( I n) were shown to be more stable than their meta-substituted ( II n) analogues due to stronger hydrogen bonding interactions. The computed reactivity parameters showed that the position of ester moiety has a significant impact on the acids reactivity. The absorbance spectra of both the 3- (or 4)- n -alkanoyloxy benzoic acids revealed a blue shift with the increment of the of alkyl chain size; however, the energy band gaps of 3- n -alkanoyloxy benzoic derivatives were found to be slightly higher than those of the 4- n -alkanoyloxy benzoic acids. Moreover, the photoluminescence spectrum of the prepared materials is rather broad, and exhibited a red shift as the alkyl chain length increases. The fluorescence lifetime shown to rise as alkyl chain length grows longer, and 3- n -alkanoyloxy benzoic acids have slightly longer lifetime compared to their 4- n -alkanoyloxy benzoic analogues. Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. (© 2023 The Authors.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu