title: Metal coordination study at Ag and Cd sites in crown thioether complexes through DFT calculations and hyperfine parameters.
abstract: Structural and electronic properties of [C12H24S6X], [C13H26S6OX], and [C14H28S6OX] (X: Ag(+), Cd(2+)) crown thioether complexes were investigated within the framework of the density functional theory (DFT) using the projector augmented wave (PAW) method. The theoretical results were compared with time-differential perturbed γ-γ angular correlations (TDPAC) experiments reported in the literature using the (111)Ag→(111)Cd probe. In the case of X=Ag(+), a refinement of the structure was performed and the predicted equilibrium structures compared with available X-ray diffraction experimental data. Structural distortions induced by replacing Ag(+) with Cd(2+) were investigated as well as the electric-field gradient (EFG) tensor at the Cd(2+) sites. Our results suggest that the EFG at Cd(2+) sites corresponds to the Ag(+) coordination sphere structure, i.e., before the structural relaxations of the molecule with X=Cd(2+) are completed. The results are discussed in terms of the characteristics of the TDPAC (111)Ag→(111)Cd probe and the time window of the measurement, and provide an interesting tool with which to probe molecular relaxations.
authors: Instituto de Física, Universidade de São Paulo, Rua do Matão Travessa R, Nr.187, Cidade Universitária, CP 66318, 05508-090, São Paulo, Brazil.
authors: Rafael R
authors: RR
authors: do Nascimento
authors: Filipe C D A
authors: FC
authors: Lima
authors: Marcos B
authors: MB
authors: Gonçalves
authors: Leonardo A
authors: LA
authors: Errico
authors: Mario
authors: M
authors: Rentería
authors: Helena M
authors: HM
authors: Petrilli
mesh_terms: D002104:Cadmium / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory; D012834:Silver / Q000737:chemistry*; D013440:Sulfides / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D013440:Sulfides; D002104:Cadmium; D012834:Silver