A new vibrational study of chromyl fluorosulfate, CrO2(SO3F)2 by DFT calculations

We have prepared chromyl fluorosulfate and characterized it by infrared spectroscopy. The density functional theory (DFT) has been used to study its structure and vibrational properties. Employing the B3LYP, B3P86 and B3PW91 levels of theory, the molecular structure of the compound has been theoretically determined in gas phase and the harmonic vibrational frequencies were evaluated at the same levels. The calculated harmonic vibrational frequencies for chromyl fluorosulfate are consistent with the experimental IR spectrum. These calculations gave us a precise knowledge of the normal modes of vibration taking into account the type of coordination adopted by fluorosulfate groups of this compound as monodentate and bidentate ligands. We have also made the assignment of all the observed bands in the IR spectrum for chromyl fluorosulfate. The nature of the CrO and Cr ← O bonds and the topological properties of the compound were investigated and analyzed by means of Natural Bond Order (NBO) and Bader's Atoms in Molecules theory (AIM), respectively.