Assessment of the molecular structure and spectroscopic properties of CF3-substituted sulfinylaniline derivatives

• Published in: Journal of molecular structure 2021-04, Vol.1230, p.129879, Article 129879
• Main Authors: Chemes, Doly M., Lezama, José O.G., Cutin, Edgardo H., Robles, Norma Lis
• Format: Article
• Language: English
• Subjects: AIM approach; DFT calculations; Spectral characterization; Substituent effect; Sulfinylaniline derivatives
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2021.129879

•CF3 monosubstituted sulfinylaniline isomers were prepared from suitable precursors.•The presence of the CF3 group determines different conformational properties.•Intramolecular anti-hydrogen interactions were revealed by AIM and NMR studies.•The effects exerted by the CF3 group on spectroscopic signals were discussed. The presence of a perfluorinated functional group as a substituent of the aromatic ring in m- and o-trifluoromethylsulfinylaniline may provide conformational and vibrational properties of interest for the synthesis of compounds of pharmacological relevance, as it was observed for other N-sulfinylaniline derivatives previously reported. The air sensitive and highly reactive compounds under study were prepared by the reaction of the corresponding aniline derivatives and thionyl chloride. The liquid samples were characterized by FT IR, Raman and NMR (1H and 13C) spectroscopies and GC/MS spectrometry. The experimental spectra indicate the presence of a single conformer of syn geometry (syn of the C-N bond with respect to the S=O bond), in good agreement with results obtained by quantum chemical calculations derived from the Functional Density Theory. The stable conformation found as the global minimum of the potential energy surface was rationalized by considering intramolecular orbital interactions evinced by a Natural Bond Orbital (NBO) analysis and the quantum theory of Atoms In Molecules (AIM). Through this last approach, an intramolecular C-H⋅⋅⋅O interaction meeting the characteristics of an anti-hydrogen bond was found. [Display omitted]