Computational study of the infrared spectrum of acetic acid, its cyclic dimer, and its methyl ester

Amines in the Earth’s Atmosphere: A Density Functional Theory Study of the Thermochemistry of Pre-Nucleation Clusters

“…The most stable isomers (within 2 kcal mole í1 of the most stable isomer/global minimum) obtained at the PW91PW91/6-31+G* level have been optimized using the PW91PW91/6-311+G(3df,3pd) method to obtain the final results. The choice of the computational method is based on the satisfactory performance of the PW91PW91 [46] on atmospheric clusters, including predicting the Gibbs free energies, structural characteristics and vibrational spectra in a very good agreement with experiments and ab initio studies, and availability of large amount of data for different atmospheric species/clusters computed at PW91PW91/6-311+G(3df,3pd) level of theory for comparison [24][25][26][27][28][29][30]34]. The availability of data for ternary sulfuric acid-water-ammonia clusters computed at the same level of theory is a very important factor because the assessment of different nucleation pathways, which is based on the analysis of the reaction free energies computed using the same method, is clearly more legitimate than that based on the comparison of results obtained at different levels of theory [47].…”

“…The ability of computational quantum chemical methods to provide an adequate description of molecular interactions in nucleating vapours has been pointed out in Nadykto et al [24], in which the classical problem of the ion sign preference established in back 1897 by Wilson [1] has been solved. Recently, computational chemical studies of atmospheric species have become a focus of intense activity [24][25][26][27][28][29][30][31][32][33][34][35][36]. Although a large number of the computational quantum studies considering atmospheric clusters has been published within the last five years, only a few are dedicated to the interaction of common organics with atmospheric nucleation precursors [32,34,35].…”

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

“…[24] Vibrational spectroscopic study of acetate group was reported by Ibrahim and Koglin. [25] Computational study of the IR spectrum of acetic acid, its cyclic dimer and its methyl ester was reported by Lewandowski et al [26] The molecular structure of acetic acid has been studied in the gas phase by both microwave spectroscopy [27,28] and electron diffraction. [29] The assessment of solid-state composition of an active salicylanilide compound (N- [5-chloro-4-[(4-chlorophenyl)cyanomethyl]-2-methylphenyl]-2-hydroxy-3,5-diiodobenzamide by FT-Raman spectroscopy was reported by Spiegeleer et al [30] Diclofenac sodium, which consists of a phenylacetate group, a secondary amino group and a dichlorophenyl ring, is a well-known representative of nonsteroidal antiinflammatory drugs.…”

FT‐IR, FT‐Raman, and computational calculations of 4‐chloro‐2‐(3‐chlorophenyl carbamoyl)phenyl acetate

“…[25] The assessment of solid state composition of an active salicylanilide compound by FT-Raman spectroscopy is reported by Spiegeleer et al [26] Diclofenac sodium, which consists of a phenylacetate group, a secondary amino group, and a dichlorophenyl ring, is a well known representative of nonsteroidal anti-inflammatory drugs. [27] Computational study of the infrared spectrum of acetic acid, its cyclic dimer, and its methyl ester are reported by Lewandowski et al [28] The molecular structure of acetic acid has been studied in the gas phase by both microwave spectroscopy [29,30] and electron diffraction. [31] To our knowledge, no theoretical HF or density functional theory (DFT) calculations, or detailed vibrational infrared and Raman analyses, have been performed on the title compound.…”