Search

In the present work, we report the experimental and computational investigations of 3-Hydroxy-4-nitrobenzaldehyde (3H4NB) were examined. Comparing observed and simulated vibrational spectra allowed for the identification of characteristic frequencies and the attribution of band names. For the density functional theory (DFT) calculations, the LSDA functional with 6-311 + G(d,p) degree of approximation was used. Furthermore, the same level of theory was used to calculate molecular orbitals such as natural bond orbitals (NBOs) and the HOMO-LUMO energy gap. The condensed Fukui function and the molecular electrostatic potential (MEP) surface were used to determine the relative electrophilicity and nucleophilicity of the current molecule. Intermolecular hydrogen bonding interactions are studied using Hirshfeld surface analysis and fingerprint plots. Molecular docking analysis was used to investigate the compound's biological activities. The hydrogen bond active binding residues and binding energy of a chosen chemical with carcinogenic activity targets were examined. [ABSTRACT FROM AUTHOR]

The conformational study of the 2,3,4,5 tetrafluorobenzoic acid molecule (TFBA) was performed by density functional theory (DFT) using B3LYP functional with 6–311++G(d,p) basis set. Vibrational frequencies were calculated at the same level of theory for the optimized stable structure. The existence of hydrogen bonding was predicted through experimental FTIR spectrum and interpreted with the formation of dimer structure. The natural bond orbital (NBO) analysis and molecular electrostatic potential (MEP) were made on DFT/B3LYP/6-311++G(d,p) level for an extensive analysis on hydrogen bonding. The calculated vibrational frequencies of TFBA monomer were compared with experimental frequencies and were found to be in good agreement. Intermolecular hydrogen bonding energy has also been calculated by topological study. [ABSTRACT FROM AUTHOR]

The density functional theory (DFT) and Hatree–Fock (HF) method was performed at 6-311++G ∗∗ level to derive the equilibrium geometry, vibrational wavenumbers, infrared intensities and Raman scattering activities of 2,3,4,5,6 pentafluorobenzoic acid molecule (PFBA). The conformer study of the monomer PFBA was also undertaken. The possibility of intermolecular hydrogen bonding and the dimeric form of the molecule was predicted using vibrational analysis of the monomer. The effects of molecular association through O H⋯O hydrogen bonding have been described in the dimer structure using geometrical structure analysis, natural bond orbital analysis (NBO), molecular electrostatic potential (MEP) maps and Mulliken charge analysis. [ABSTRACT FROM AUTHOR]

Highlights: [•] It provides the ability of the B3LYP/6-31G** computational method. [•] Prediction of most stable structure and structural properties were done. [•] The complete vibrational assignment and spectroscopic analysis have been carried out. [•] The research shows the presence of intramolecular interaction in the title compound. [•] It explains a good correlation between the experimental and theoretical data. [ABSTRACT FROM AUTHOR]

Highlights: [•] The electric dipole moment of DCT and CFT were carried out. [•] FTIR and FT-Raman spectra were recorded and TED calculations were reported. [•] HOMO and LUMO energy gap explains the charge transfer taking place in the molecule. [•] The vibrational wave number and NMR were calculated by B3LYP/6-31G*. [•] Effects of methyl and halogen substitutions in the vibrational property were studied. [ABSTRACT FROM AUTHOR]