Molecular structure, NMR and vibrational spectral analysis of 2,4‐difluorophenol by ab initio HF and density functional theory

Abstract

Quantum chemical calculations of energies, geometries and vibrational wavenumbers of 2,4-difluorophenol (2,4-DFP) were carried out by using ab initio HF and density functional theory (DFT/B3LYP) methods with 6-311G(d,p) as basis set. The optimized geometrical parameters obtained by HF and DFT calculations are in good agreement with related molecules. The best level of theory in order to reproduce the experimental wavenumbers is the B3LYP method with the 6-311G(d,p) basis set. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. A detailed interpretation of the infrared and Raman spectra of 2,4-DFP is also reported. The entropy of the title compound was also performed at HF/6-311G(d,p) and B3LYP/6-311G(d,p) levels of theory. The isotropic chemical shift computed by 1 H, 13 C NMR analyses also shows good agreement with experimental observations. The theoretical spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed.

Spectroscopic Investigation of cis-2,4-Difluorophenol Cation by Mass-analyzed Threshold Ionization Spectroscopy

“…Anbarasan and coworkers recorded the infrared and Raman spectra of 24DFP in the condensed phase and reported the active vibrations of this molecule in the S 0 state. 15 They also performed the quantum chemical calculations to support their experimental results. 15 The ionization energy (IE) of this molecule has been reported on the basis of the conventional photoelectron spectroscopic experiments.…”

“…15 They also performed the quantum chemical calculations to support their experimental results. 15 The ionization energy (IE) of this molecule has been reported on the basis of the conventional photoelectron spectroscopic experiments. 16 To the best of our knowledge, detailed spectroscopic data about the 24DFP in electronically excited S 1 and cationic ground D 0 state are not yet available in the literature.…”

“…[1][2][3] Many fluorinated benzene derivatives, [4][5][6][7][8][9][10][11][12][13][14][15][16] are extensively studied by various spectroscopic methods. 2-Fluorophenol is regarded as one of the classic example of intramolecular hydrogen-bonding systems which have been the subject of various studies.…”

Probing the compound (E)-2-[(4-bromophenylimino)methyl]-6-ethoxyphenol mainly from the point of tautomerism in solvent media and the solid state by experimental and computational methods

“…Generally, the in-plane bending and out-of-plane bending vibrations of OH groups in phenols span the region 1300-1400 cm À1 and 517-710 cm À1 , respectively [31]. The band observed at 1340 cm À1 was assigned to in-plane bending vibration of OH group while the band at 778 cm À1 was attributed to its outof-plane bending vibration.…”

“…The absorption band at 1613 cm À1 is due to t(C@N) stretching vibration. The aromatic CAH stretching, CAH in-plane bending and CAH out-of-plane bending vibrations appear in 3000-3100 cm À1 , 1100-1500 cm À1 and 800-1000 cm À1 frequency ranges, respectively [31,32]. The absorption bands at 3086 and 3061 cm À1 correspond to the aromatic CAH stretching vibrations of the title compound.…”