Akademik Veri Yönetim Sistemi
JOURNAL OF MOLECULAR STRUCTURE, cilt.1295, 2024 (SCI-Expanded)
Diltiazem and Verapamil are two important drug molecules in a separate group of Calcium Channel Blockers. The purpose of this work is to determine and compare the structural and spectroscopic properties of these two molecules using a number of experimental techniques and quantum chemical calculations. Compounds were characterized spectroscopically using FT-IR, Raman, NMR (1H, 13C, and DEPT), and UV-vis methods. Further-more, the Density Functional Theory (DFT) method, Becke's three-parameter hybrid functional (B3LYP), and the 6-311++G(d,p) basis set were used to determine the ground state geometric structures of molecules, and the spectroscopic properties of the obtained optimum structures were investigated computationally. The optimization studies performed under vacuum circumstances and for the isolated molecules were found to be very close to the experimental results. In fact, r.m.s. values were discovered for Diltiazem and Verapamil with bond lengths of 0.013 and 0.024, and bond angles of 1 degrees and 2 degrees, respectively. The vibration characteristics of the compounds were discovered using the collected FT-IR and Raman spectra, and significant vibrational modes were assigned. After scaling, it was revealed that the quantum chemical data was congruent with the experimental ones, and that the characteristic vibrational modes were appropriately predicted. DFT calculations effectively determine molecules' structures due to internal consistency, despite being slightly distant from experimental data. Theoretical values for carbon and hydrogen atoms are better in agreement with observed values when scaling with 0.92 and 0.90. From the UV-vis spectra, Diltiazem HCl absorbance peaks were found at 207 and 237 nm, whereas Verapamil HCl absorbance peaks were identified at 203, 229, and 278 nm. When the theoretical calculations and experimental findings were compared, the anticipated absorption peaks were found to have shifted nearer the visible area. Furthermore, Hirshfeld surfaces and Molecular Electrostatic Potential surfaces were obtained and analyzed in order to better understand the electronic characteristics. The TDOS and PDOS (total and partial density of state) spectra were also studied. Finally, using the HOMO and LUMO energy values, the critical chemical parameters were evaluated, and it was discovered that both molecules had positive electron affinity and electro-negativity values, indicating that they will accept electrons when the electron-nucleus attraction exceeds the electron-electron repulsion.