Synthesis, experimental and theoretical characterization of m-fluorosulfinylaniline

Abstract

The synthesis of m-fluorosulfinylaniline together with a tentative assignment of the vibrational, NMR and mass spectra are reported. Quantum chemical calculations predict two stable conformers, with very similar energies, both of which possess in the liquid phase syn structure of the -N[double bond, length as m-dash]S[double bond, length as m-dash]O moiety (syn of the S[double bond, length as m-dash]O double bond relative to the C-N single bond). Both conformers belong to the CS symmetry group and differ by the relative orientation of the fluorine atom and the NSO group. However, the FT-IR, FT-Raman and NMR spectra do not allow a distinction between these two conformers. The experimentally observed spectral data (FT-IR, FT-Raman, 1H and 13C and GC-mass spectrometry) of the title compound are compared with the spectral data obtained by quantum chemical calculations and the gauge including atomic orbital (GIAO) method (DFT/B3LYP approximation using 6-311+G(df), 6-311++G(df,pd) and cc-pVTZ basis sets). Moreover, natural bond orbital (NBO) analysis is applied for studying the stability of the molecule upon charge delocalization in order to provide an explanation of its electronic properties.