Journals / Eskişehir Teknik Üniversitesi Bilim ve Teknoloji Dergisi B - Teorik Bilimler / 2021 / Cilt: 9 - Sayı: Iconat Special Issue 2021

DFT/TD-DFT ANALYSIS OF 2-CHLORO-7-METHYLQUINOLINE-3-CARBALDEHYDE USING COMPUTER COMPUTING METHOD

Pages
85–93
DOI
—

Abstract

Quinolines are the essence of many natural products, drugs and were found in synthetic compounds. Quinoline derivatives containing a quinoline ring are used in a variety of biological and pharmaceutical activities, e.g. anticancer, antibacterial, antifungal, antiplasmodial, antihistamine, antimalarial and antituberculosis. In this study, 2-Chloro-7-Methylquinoline-3-Carbaldehyde (ClMQC) molecule, which is a quinoline derivative, was selected and analyzed. The stable structures of ClMQC molecule with minimum energy were investigated by density functional theory (DFT) together with B3LYP/6-311++G(d,p) method. It was seen that there are two different conformers (trans and cis) with minimum energy in the scanning made depending on the C─C─C=O dihedral angle. As a result of the calculation with the B3LYP/6-311++G(d,p) level, the energy difference (E+ZPV) between the two conformers was calculated as 14.60 kJ mol-1. Oscillator strength and excitation energies were analyzed by calculating the time-dependent DFT (TD-DFT). The energy differences between the excited energy levels are given in the graph. This was done by adding the ground state energies of both conformers. The energy corresponding to HOMO-LUMO was calculated to correspond to the S0→S2 transition for both conformers. The excitation energy values were calculated as 3.75 and 3.84 eV for trans and cis, respectively.

Özet

Quinolines are the essence of many natural products, drugs and were found in synthetic compounds. Quinoline derivatives containing a quinoline ring are used in a variety of biological and pharmaceutical activities, e.g. anticancer, antibacterial, antifungal, antiplasmodial, antihistamine, antimalarial and antituberculosis. In this study, 2-Chloro-7-Methylquinoline-3-Carbaldehyde (ClMQC) molecule, which is a quinoline derivative, was selected and analyzed. The stable structures of ClMQC molecule with minimum energy were investigated by density functional theory (DFT) together with B3LYP/6-311++G(d,p) method. It was seen that there are two different conformers (trans and cis) with minimum energy in the scanning made depending on the C─C─C=O dihedral angle. As a result of the calculation with the B3LYP/6-311++G(d,p) level, the energy difference (E+ZPV) between the two conformers was calculated as 14.60 kJ mol-1. Oscillator strength and excitation energies were analyzed by calculating the time-dependent DFT (TD-DFT). The energy differences between the excited energy levels are given in the graph. This was done by adding the ground state energies of both conformers. The energy corresponding to HOMO-LUMO was calculated to correspond to the S0→S2 transition for both conformers. The excitation energy values were calculated as 3.75 and 3.84 eV for trans and cis, respectively.

Keywords: 2-Chloro-7-Methylquinoline-3-Carbaldehyde, DFT/TD-DFT, Excitation energies, HOMO-LUMO