Structural and vibrational study of chromyl chorosulfate

Abstract

In this chapter, a theoretical study of the structural and vibrational properties of the chromyl chlorosulfate compound using density functional theory (DFT) methods is presented. The results show two stable molecules for the chlorosulfate in gas phase and an average of both structures probably present in the solid phase. On the other hand, a complete assignment of all observed bands in the infrared spectrum for the compound was performed by combining DFT calculations with Pulay’s Scaled quantum mechanics force field (SQMFF) methodology in order to fit the theoretical wavenumber values to the experimental ones. The calculations gave us precise knowledge of the normal modes of vibration taking into account the monodentate and bidentate coordination modes for the chlorosulfate ligands. The results were then used to predict the Raman spectra and molecular geometry of the compound, for which there are no experimental data. In this chapter, the scaled force constants and the scaling factors are also reported together with a comparison of the obtained values for similar compounds. Besides, the characteristics and nature of the Cr–O and Cr / O bonds of the two stable structures were studied through the Wiberg’s indexes calculated by means of the natural bond orbital (NBO) study, while the corresponding topological properties of the electronic charge density are analyzed by employing Bader’s Atoms in the molecules theory (AIM).