Synthesis, Spectral Characterization and Fluorescent Assessment of 1,3,5-Triaryl-2-pyrazoline Derivatives: Experimental and Theoretical Studies

Mohammad M Ibrahim; Mahmoud Al-Refai; Khurshid Ayub; Basem F Ali

doi:10.1007/s10895-016-1837-9

Synthesis, Spectral Characterization and Fluorescent Assessment of 1,3,5-Triaryl-2-pyrazoline Derivatives: Experimental and Theoretical Studies

J Fluoresc. 2016 Jul;26(4):1447-55. doi: 10.1007/s10895-016-1837-9. Epub 2016 May 24.

Authors

Mohammad M Ibrahim¹, Mahmoud Al-Refai¹, Khurshid Ayub², Basem F Ali^{3

4}

Affiliations

¹ Department of Chemistry, Al al-Bayt University, Mafraq, 25113, Jordan.
² Department of Chemistry, COMSATS Institute of Information Technology, Abbottabad, 22060, Pakistan.
³ Department of Chemistry, Al al-Bayt University, Mafraq, 25113, Jordan. bfali@kfu.edu.sa.
⁴ Department of Chemistry, King Faisal University, Al-Hasa, Saudi Arabia. bfali@kfu.edu.sa.

PMID: 27220512
DOI: 10.1007/s10895-016-1837-9

Abstract

Two new pyrazoline derivatives, namely 5-(4-bromophenyl)-3-(5-chlorothiophen-2-yl)-1-phenyl-4,5-dihydro-1H-pyrazole (3) and 5-(4-bromophenyl)-3-(2,5-dichlorothiophen-3-yl)-1-phenyl-4,5-dihydro-1H-pyrazole (4) have been synthesized and characterized based on their spectral (IR, (1)H and (13)C NMR and MS) data and microanalysis. The fluorescence properties of 3 and 4 were studied by UV-Vis and emission spectroscopy. For compound 3, a fluorescence emission was observed in the blue region of the visible spectrum. The effect of different solvents on fluorescence was also investigated. Density Functional Theory calculations have also been performed to gain insight into geometric, electronic and spectroscopic properties of the pyrazoline derivatives. Both structures are analysed and compared in order to rationalize the different behaviour in 3 and 4.

Keywords: Chalcone; DFT calculations; Fluorescence; Pyrazolines; Spectral characterization.