Experimental and theoretical characterization of Sn(IV), Sb(III) and Bi(III) Xanthate

The O-alkyldithiocarbonates, so-called xanthates (Xn) are a group of ligands that in metallic complexes derivatives can have extensively applications in pharmaceutical, fungicides, pesticides, thin films for phovoltaic devices and even in therapy for HIV infection. Xanthates have the propriety of decompose in broader temperature ranges and also it is easy synthesized, in large scale[1]. In the other hand, in literature there is a lack of structural and spectroscopic characterization study for some aryl xanthates, and a much smaller number of studies containing theoretical analyzes of this ligands and its complexes. This study presents the experimental and theoretical characterization of several new alkyxanthates complex with Sn, Sb and Bi. The complexes was formed following the synthesis route described by literature[2,3] and by the equation (M = Sn, Sb, Bi; y= 4 for Sn and y=3 for Sb and Bi; R = etyl, i-propyl and nbutyl). The characterization was performed in solid phase using IV, UV and Raman equipment from LAMEUFF. Theoretical study were submitted with the DFT method CAM-B3LYP/6-311+G(d,p) for light elements (C, O, S and H) and the ECP-LANL2DZ basis set to metals, using Gaussian 09 program. This preliminary study of the xanthate complexes presents the experimental and theoretical IR spectra and the vibrational assigned of both spectra, as well as its geometries, described in literature as an octahedral complex, with two xanthate as a bidentate and two monodentate ligand (Cl or xanthate. The IR/Raman experimental characterization for structure found[3], confirmed the presence of xanthates through the bands shown in the table below. IR vibrational spectra simulated by the theoretical calculation permitted a refined assignment, mainly in low wavenumbers and resulted in a good approximation with the experimental spectra. We intend to report the characterization of this entire row of xanthate complexes, for a good comprehension of its structure and synthesis. The comparison with the theoretical data will enhance this understanding of the molecules.