title: An experimental and theoretical vibrational spectroscopic study of [AsPh(4)](2)[Sn(dmit)(3)] x Me(2)CO.
abstract: As shown previously by X-ray structure determinations, [tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate(IV)](2-) salts, [Q](2)[Sn(dmit)(3)], contain isolated cations and dianions. While the tin centres generally having octahedral geometries, the overall shapes of the dianions of these complexes in the solid state can differ with conformations varying from T, Y to asymmetrical arrangements. We now report, as a follow up to our earlier study on the Y-shaped complex, [NEt(4)](2)[Sn(dmit)(3)], an experimental and theoretical study of the vibrational spectra of solid solvated {[AsPh(4)](2)[Sn(dmit)(3)] x Me(2)CO}, in which the dianion has a T-shaped conformation. The infrared and Raman spectra, recorded from 4000 to 150 cm(-1), have been analysed by different ab initio calculations based on restricted Hartree-Fock (RHF) and density functional theory (DFT-Beck3LYP). The calculations were carried out on isolated dianions and cations with the 6-31G and 6-31G(d) basis sets and effective core potentials of Steven, Bash and Krauss (SBK). Fundamentals, overtones and combinations have been assigned. Generally, the Y- and T-shaped dianions exhibit similar infrared/Raman spectra, apart from differences in the C=C and the symmetrical M-S stretching frequencies: such differences can be used diagnostically to distinguish the overall shape of the tris(chelated)metallate dianion.
authors.affiliation: Departamento de Química Inorgânica, Instituto de Química, Universidade Federal do Rio de Janeiro, 21945-970 Rio de Janeiro, RJ, Brazil.
authors.forename: Glaucio B
authors.initials: GB
authors.lastname: Ferreira
authors.forename: Eduardo
authors.initials: E
authors.lastname: Hollauer
authors.forename: Nadia M
authors.initials: NM
authors.lastname: Comerlato
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell
mesh_terms: D008958:Models, Molecular; D008968:Molecular Conformation; D009947:Organotin Compounds / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013871:Thiones / Q000737:chemistry*; D014732:Vibration; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D009947:Organotin Compounds; D013438:Sulfhydryl Compounds; D013871:Thiones; C510117:tetraphenylarsenic tris(1,3-dithiole-2-thione-4,5-dithiolate)stannate(IV)