Layered Crystal Structure and Vibrational Spectra of Sodium Trichloromethanesulfonate – An Eperimental and Theoretical Study

The NaCCl3SO3.H2O salt was studied by X-ray diffraction methods, which show that it crystallizes in the monoclinic P21/c space group, with a = 12.558(5), b = 5.814(3), c = 10.679(5) A, β = 103.76(3)°, and Z = 4. The solid is arranged into neutral slabs, parallel to each other and to the crystal bc plane, being each slab held mainly by ionic forces. An infrared and Raman study of that compound was also performed and an assignment of the observed spectral features was made, correcting results previously reported by other authors. The vibrational study was supported by quantum chemistry calculations at the DFT level, from which the theoretical frequencies of vibration and a force field for the anion were obtained. That force field was subsequently adjusted to reproduce the set of experimental frequencies.