Structural and vibrational studies and molecular force field of zinc difluoromethanesulfinate

Abstract

The new compound zinc difluoromethanesulfinate salt, Zn(SO2CF2H)2 (recently synthesized by Fujiwara et al. [12]) was characterized by infrared and Raman spectroscopies. The ab initio calculations were used to study the structures and vibrational properties of the compound and its SO2CF2H− anion. Employing the HF and B3LYP levels of theory, the molecular structures of both species were theoretically determined in gas phase and the harmonic vibrational frequencies were evaluated at the same levels. Also, the structure of a monohydrated complex in accordance with the observed experimental structure was optimized. The calculated harmonic vibrational frequencies for zinc difluoromethanesulfinate are consistent with the experimental IR and Raman spectra. These calculations gave us a precise knowledge of the normal modes of vibration taking into account the type of coordination adopted by difluoromethanesulfinate groups of this compound as monodentate and bidentate ligands. A complete assignment of all the observed bands in the IR and Raman spectra for zinc difluoromethanesulfinate was performed. The nature of the CF, SO and Zn←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.