Navegando por Autor "Vieira, Heulla Pereira"

Filtrar resultados informando as primeiras letras
Agora exibindo 1 - 2 de 2
  • Nenhuma Miniatura Disponível
    Item
    Syntheses, crystal structure and spectroscopic characterization of novel N-R-sulfonyldithiocarbimate and triphenylphosphine nickel(II) complexes.
    (2002) Oliveira, Marcelo Ribeiro Leite; Vieira, Heulla Pereira; Perpétuo, Genivaldo Julio; Janczak, Jan; Bellis, Vito Modesto De
    Three new complexes of the general formula: [Ni(PPh3)2(RSO2N_/CS2)] where R_/2-CH3C6H4 (1), 4-CH3C6H4 (2) and 4-BrC6H4 (3) were obtained in crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimates (K2(RSO2N_/CS2)) and triphenylphosphine with nickel(II) chloride in ethanol_/water. The 1 complex crystallizes in the centrosymmetric space group of the triclinic system with two molecules per unit cell, while 2 and 3 complexes crystallize in the Pbca space group of the orthorhombic system with eight molecules per unit cell. The X-ray single-crystal analysis showed that all complexes present a similarly distorted square-planar configuration around the nickel atom due to the steric effect of the triphenylphosphine ligands and the didendate chelation by the two sulfur atoms of the dithiocarbimate ligand. The IR and UV_/Vis spectral data are consistent with the formation of almost square-planar nickel complexes. The 1H NMR, 13C NMR, 31P NMR spectra showed the expected signals for the triphenylphosphine and the dithiocarbimate moieties.
  • Nenhuma Miniatura Disponível
    Item
    Syntheses, crystal structure and spectroscopic characterization of novel N-R-sulfonyldithiocarbimate zinc(II) complexes.
    (2003) Perpétuo, Genivaldo Julio; Oliveira, Marcelo Ribeiro Leite; Janczak, Jan; Vieira, Heulla Pereira; Amaral, Fabiana Fonseca do; Bellis, Vito Modesto De
    Two new compounds of the general formula: (Ph4P)2[Zn(RSO2N@CS2)2], where R¼C6H5 (1) and 4-CH3C6H4 (2) were obtained in crystalline form by the reaction of the appropriate potassium N-R-sulfonyldithiocarbimate (RSO2N@CS2K2) with zinc(II) acetate dihydrate in dimethylformamide. The compounds crystallise in the centrosymmetric space group of the triclinic system with Z ¼ 2. The single crystal X-ray analysis showed a similarly distorted tetrahedral configuration around the zinc(II) cation due to the bidentate chelation by two sulfur atoms of the N-R-sulfonyldithiocarbimate ligands. Ionic interaction between oppositely charged moieties, i.e., the bis(N-R-sulfonyldithiocarbimato)zincate(II) dianion [Zn(RSO2N@CS2)2]2_ and tetraphenylphosphonium cation Ph4Pþ and van der Waals interactions determine the crystal packing motif. The IR data are consistent with the formation of zinc–dithiocarbimate complexes. The 1H NMR and 13C NMR spectra showed the expected signals for the tetraphenylphosphonium cation and the dithiocarbimate moieties.