Comment on: “FT-IR, FT-Raman and UV spectral investigation; computed frequency estimation analysis and electronic structure calculations on 1-nitronaphthalene” by M. Govindarajan and M. Karabacak [Spectrochim. Acta A 85 (2012) 251–260

Abstract

The title paper [1] incorrectly establishes that, in gas phase the global minimum energy structure of 1-nitronaphthalene is planar (Cs symmetry). By contrast, present calculations indicate that the planar Cs form is an unstable structure on the potential energy surface, exhibiting an imaginary vibrational wavenumber value corresponding to the torsional mode of the nitro group around the C–N bond. At the B3LYP/6-311++G(d,p) level of calculation the global minimum energy structure of 1-nitronaphthalene in gas phase has a non-planar geometry, characterized by O–N–C–C dihedral angles of ca. 30° and lying 0.35kcal/mol below the Cs form.