FT-IR, HF and DFT structural, vibrational analysis of 5-chloro-3-(2-(4-ethylpiperazin-1-yl)-2-oxoethyl)benzo[d]thiazol-2(3H)-one molecule

Molecular Structure, DFT, Vibrational Spectra with Fluorescence Effect, Hirshfeld Surface, Docking Simulation and Antioxidant Activity of Thiazole Derivative

“…In our case, this vibration indicated at 3398 cm −1 in FT‐IR, with predicted value at 1693.42 cm −1 . Stretching vibration of C=O group is expected to appear at 1715–1680 cm −1 and have been reported by literature in FT‐IR at 1651 cm −1 and 1694 cm −1 . In our investigation, the band with very strong intensity at 1701.87 cm −1 and 1693.42 cm −1 in FT‐IR and Raman, respectively, assigned to C=O stretching vibration with calculated wavenumber value at 1682.90 cm −1 .…”

“…In our investigation, the band with very strong intensity at 1701.87 cm −1 and 1693.42 cm −1 in FT‐IR and Raman, respectively, assigned to C=O stretching vibration with calculated wavenumber value at 1682.90 cm −1 . The differences between the experimental and predicted wavenumbers can be ascribed due to the conjugation or formation of hydrogen bonds . The symmetric stretching and wagging vibrations of CH2, occur in the region 2885±45 cm −1 , 1390 cm −1 , respectively .…”

“…The C–H out‐of‐plane bending vibrations are strongly coupled and occur in the region 1000–700 cm −1 . Taşal et al . observed this vibration at 942, 797, 702, 669 and 573 cm −1 in the FT‐IR.…”

“…The C−S stretching vibration was predicted at the computed wavenumber of 823.06 cm −1 , which agrees well with the FT‐IR and Raman bands at 820.56 and 854.91 cm −1 , respectively. However, this vibration usually occurs in the region 700–600 cm −1 , but some researchers have reported different wavenumbers at 501 cm −1 , 832 and 683 cm −1 , and 644 cm −1 in FT‐IR, respectively. The shifting of this wavenumber to the higher side could be attributed to the symmetry lacking and the presence of heavy atoms such as S and N in the thiazole ring.…”

Synthesis, spectroscopic and computational characterization of the tautomerism of pyrazoline derivatives from chalcones

“…Molecular structure, conformational stability and vibrational frequencies have been studied by ab initio and DFT methods [22,[25][26][27][28]. The support of quantum chemistry methods, mostly based on density functional theory (DFT), has been essential for the interpretation of both NMR and Raman spectroscopy results for the assignment of spectra from both techniques, as well as on the calculation of total energy changes between different tautomeric species.…”