Document Details

Document Type : Thesis 
Document Title :
Investigating the Electronic Properties of New Derivatives of Quinoline-3-Carbonitrile Dyes Using Density Functional Theory Calculations
دراسة الخواص الالكترونية لمشتقات جديدة لصبغات الكوينولين−٣−كاربونيتريل بواسطة حسابات نظرية الكثافة الوظيفية
 
Subject : Faculty of Sciences 
Document Language : Arabic 
Abstract : Quinoline and its fused heterocyclic derivatives were proved as life-saving drugs. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) have been used to investigate the geometrical structures, electronic and optical properties of two new derivatives of quinoline-3-carbonitrile dyes; 4-[4-(dimethylamino) phenyl]-2-oxo-1,2,5,6-tetrahydrobenzo[h]-quinoline-3-carbonitrile (MAPC) and 4-(4-chlorophenyl) 2-oxo-1,2,5,6-tetrahydrobenzo[h]quinoline-3-carbonitrile (CPC). Additionally, the thermal tautomerization (1,3-intramolecular proton transfer), water complexes and acid-base properties of one of the two compounds (MAPC) have been investigated. The optimized structures of MAPC and CPC molecules were calculated at three functionals: B3LYP, CAM-B3LYP and ωB97XD with 6-311G++(d,p) basis set and compared with the available crystallographic data of very similar molecules. The experimental and calculated geometrical parameters were in good agreement. Non-linear optical (NLO) properties related to polarisability and hyperpolarisability of MAPC and CPC were estimated. Both molecules have NLO properties falls between two classical references (urea and p-nitroaniline), and MAPC properties are superior than that of CPC (2-fold). The intramolecular donor-acceptor interactions and charge transfer within the two molecules have been investigated applying the natural bond orbital (NBO) technique. The frontier molecular orbitals (FMOs) were represented graphically and their energies and energy gaps have been calculated. The effect of different substituents on NBO and FMO were investigated. In order to display regions of electrophilic and nucleophilic attack, the Fukui functions and molecular electrostatic potentials plots were calculated. Evaluating the global reactivity descriptors showed that both molecules exhibit good metal corrosion inhibition efficiency. The available experimental absorption and emission data for the two investigated dyes were used to rationalize the performance of the standard hybrid functional (B3LYP and long-range corrected LC-functionals (CAM-B3LYP and ωB97XD).The performance of B3LYP and LC-functionals along with the polarizable continuum model (PCM) of solvation in considering the effects of structural diversity and solvent polarity was analysed and discussed. The tautomerism of MAPC in the gas phase and in four solvents was investigated. The stability of the two tautomers (enol and keto forms) is different from gas to solvent. The 1,3-proton transfer is found to be thermodynamically forbidden with high average activation barrier (~40 kcal/mol). The optimized geometries and energies of the MAPC-water complexes are computed with BSSE correlation. Also, the protonated and deprotonated forms of MAPC are computed in order to get better understanding of the strength of the intermolecular H-bonds. 
Supervisor : Dr. Nuha Ahmed Wazzan 
Thesis Type : Master Thesis 
Publishing Year : 1438 AH
2017 AD 
Added Date : Thursday, June 8, 2017 

Researchers

Researcher Name (Arabic)Researcher Name (English)Researcher TypeDr GradeEmail
عهود سليمان القرشيAl-Qurashi, Ohoud SulimanResearcherMaster 

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