Abbreviations: ν, stretching; β, deformation in the plane; γ, deformation out of plane; τ, torsion; βR. deformation ring τR, torsion ring; ρ, rocking; τw, twisting; δ, deformation; a, antisymmetric; s, symmetric; (A1), Ring 1; (A2), Ring 2; aThis work,bFrom scaled quantum mechanics force field.
Particularly, in the IR spectrum of R(+) form in the 2000-400 cm-1 region bands with higher intensities are observed while in the higher wavenumbers region the observed IR bands are wide due to the packing forces not considered in the calculations in gas phase. Predicted Raman spectra for both forms show higher differences in the 900-100 cm-1 region evidencing higher intensities some bands of S(-) form, as observed in Figure 7. Discussions of assignments of more important groups are presented below by regions.