FT‐IR, FT‐Raman and DFT calculations of the salicylanilide derivate 4‐chloro‐2‐(4‐bromophenylcarbamoyl)phenyl acetate

Abstract

FT-IR and FT-Raman spectra of 4-chloro-2-(4-bromophenylcarbamoyl)phenyl acetate were recorded and analyzed. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using the Gaussian03 set of quantum chemistry codes. The red shift of the NH stretching wavenumber in the infrared (IR) spectrum from the computed wavenumber indicates the weakening of the NH bond resulting in proton transfer to the neighbouring oxygen atom. The simultaneous IR and Raman activations of the C O stretching mode give the charge transfer interaction through a π -conjugated path. Optimized geometrical parameters of the title compound are in agreement with similar reported structures. From the optimized structure, it is clear that the hydrogen bonding decreases the double bond character of C O bond and increases the double bond character of the C-N bonds. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivativesand is an attractive object for future studies of non-linear optics. The assignments of the normal modes are done by potential energy distribution (PED) calculations.

FT‐IR, FT‐Raman, SERS spectra and computational calculations of 4‐ethyl‐N‐(2′‐hydroxy‐5′‐nitrophenyl)benzamide

“…The calculated first hyperpolarizability of the title compound is 4.559 × 10 −30 esu, which is comparable with the reported values of similar derivatives, [97] but the experimental value is not readily available. We conclude that the title compound is an attractive object for future studies of nonlinear optical properties.…”

Vibrational spectroscopic studies and ab initio calculations of phenyl phosphate disodium salt

“…The calculated first hyperpolarizability of the title compound is 4.101 × 10 −30 esu, which is comparable with the reported values of similar derivatives, [71] but experimental evaluation of this data is not readily available. We conclude that the title compound is an attractive object for future studies of nonlinear optical properties.…”

Spectroscopic investigations and computational study of 2‐[acetyl(4‐bromophenyl)carbamoyl]‐4‐chlorophenyl acetate

“…The IR bands in the 2880-1936 cm −1 region and their broadening support intramolecular hydrogen bonding. [32] Geometrical parameters and first hyperpolarizability…”

“…This work is a part of our investigations of substituted salicylanilide derivatives. The authors have reported the spectroscopic studies of 4-chloro-2-(4-bromophenylcarbamoyl)phenyl acetate [32] and 4-chloro-2-(3,4-dichloro phenyl carbamoyl) phenyl acetate. [33] To our knowledge, no theoretical HF or DFT calculations, or detailed vibrational IR and Raman analyses, have been performed on the title compound.…”