Experimental and Theoretical Study of O-Substituent Effect on the Fluorescence of 8-Hydroxyquinoline

International Journal of Molecular Sciences

Mohie E. M. Zayed¹  Reda M. El-Shishtawy¹  Shaaban A. Elroby¹  Abdullah Y. Obaid¹  Zahra M. Al-amshany¹ 

[1] Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah B.O.208203, Saudi Arabia; E-Mails:

关键词: ether and ester derivatives;    8-hydroxyquinoline (8-HQ);    UV-visible and fluorescence spectra;    TD-DFT calculations;    electronic absorption;    natural transition orbital (NTO);   

DOI  :  10.3390/ijms16023804

来源: mdpi

【 摘 要 】

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.

【 授权许可】

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