title: Experimental and theoretical study of o-substituent effect on the fluorescence of 8-hydroxyquinoline.
abstract: The synthesis and characterization of different ether and ester derivatives of 8-hydroxyquinoline have been made. UV-visible and fluorescence spectra of these compounds have revealed spectral dependence on both solvent and O-substituent. The fluorescence intensity of ether derivatives revealed higher intensity for 8-octyloxyquinoline compared with 8-methoxyquinoline, whereas those of ester derivatives had less fluorescence than 8-hydroxyquinoline. Theoretical calculations based on Time-dependent density functional theory (TD-DFT) were carried out for the quinolin-8-yl benzoate (8-OateQ) compound to understand the effect of O-substituent on the electronic absorption of 8-hydroxyquinaline (8-HQ). The calculations revealed comparable results with those obtained from the experimental data. Optimized geometrical structure was calculated with DFT at B3LYP/6-311++G** level of theory. The results indicated that 8-OateQ is not a coplanar structure. The absorption spectra of the compound were computed in gas-phase and solvent using B3LYP and CAM-B3LYP methods with 6-311++G ** basis set. The agreement between calculated and experimental wavelengths was very good at CAM-B3LYP/6-311++G** level of theory.
authors: Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah B.O.208203, Saudi Arabia. mohiem@yahoo.com.
authors: Mohie E M
authors: ME
authors: Zayed
authors: Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah B.O.208203, Saudi Arabia. elshishtawy@hotmail.com.|Dyeing, Printing and Textile Auxiliaries Department, Textile Research Division, National Research Center, Dokki, Cairo 12622, Egypt. elshishtawy@hotmail.com.
authors: Reda M
authors: RM
authors: El-Shishtawy
authors: Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah B.O.208203, Saudi Arabia. skamel@kau.edu.sa.|Chemistry Department, Faculty of Science, Beni Suef University, Beni Suef 6251, Egypt. skamel@kau.edu.sa.
authors: Shaaban A
authors: SA
authors: Elroby
authors: Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah B.O.208203, Saudi Arabia. aobaid@kau.edu.sa.
authors: Abdullah Y
authors: AY
authors: Obaid
authors: Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah B.O.208203, Saudi Arabia. zalamshany@hotmail.com.
authors: Zahra M
authors: ZM
authors: Al-amshany
mesh_terms: D005453:Fluorescence; D008956:Models, Chemical; D008958:Models, Molecular; D015125:Oxyquinoline / Q000737:chemistry*; D011804:Quinolines / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D011804:Quinolines; D015125:Oxyquinoline