Showing papers by "Oscar E. Piro published in 2009"
TL;DR: In this paper, the properties of CH3CH2OC(S)N(H)C(O)OCH3 (II) are analyzed using a combined approach involving crystallographic data, vibration spectra and theoretical calculations.
41 citations
TL;DR: The electrochemical studies showed that the trypanocidal 5-nitroindazole derivatives yielded nitro-anion radical via one-electron process at physiological pH in the parasite according to ESR experiment with the T. cruzi microsomal fraction showing that 5-Nitroindrazole derivatives suffer bio-reduction without reactive oxygen species generation.
39 citations
TL;DR: In this article, the zinc(II) complexes of 2-benzoylpyridine-phenylhydrazone (H2BzPh), 2-bzylphosphate-para-nitrophenyl (H 2BzpNO 2 Ph) hydrazone, and 2benzylophosphamide-par ammonite (HBP) were obtained and fully characterized.
36 citations
TL;DR: In this article, the crystal and molecular structures of 2-(2′-furyl)-4,5-1H-dihydroimidazole (1) were determined by X-ray diffraction methods.
26 citations
TL;DR: In this article, four ternary complexes of copper(I) with thiosaccharin and phosphanes were prepared and characterized by spectroscopic and X-ray crystallographic methods.
22 citations
TL;DR: In this paper, the crystal structure of [CH 3 OC(O)SNH] 2 CO was determined by X-ray diffraction methods and the properties of the structure were analyzed using a combined approach with data obtained from X-Ray diffraction, vibrational spectra and theoretical calculation methods.
17 citations
TL;DR: In this article, a series of palladium(II) thiosaccharinates with triphenylphosphane (PPh3), bis(diphenyl-phosphanyl)methane (dppm), and bis(diplophosphamide)ethane(dppe) have been prepared and characterized.
Abstract: A series of palladium(II) thiosaccharinates with triphenylphosphane (PPh3), bis(diphenylphosphanyl)methane (dppm), and bis(diphenylphosphanyl)ethane (dppe) have been prepared and characterized From mixtures of thiosaccharin, Htsac, and palladium(II) acetylacetonate, Pd(acac)2, the palladium(II) thiosaccharinate, Pd(tsac)2 (tsac: thiosaccharinate anion) (1) was prepared The reaction of 1 with PPh3, dppm, and dppe leads to the mononuclear species Pd(tsac)2(PPh3)2·MeCN (2), [Pd(tsac)2(dppm)] (3), Pd(tsac)2(dppm)2 (4), and [Pd(tsac)2(dppe)]·MeCN (5) Compounds 2, 4, and 5 have been prepared also by the reaction of Pd(acac)2 with the corresponding phosphane and Htsac All the new complexes have been characterized by chemical analysis, UV/Vis, IR, and Raman spectroscopy Some of them have been also characterized by NMR spectroscopy The crystalline structures of complexes 3, and 5 have been studied by X-ray diffraction techniques Complex 3 crystallizes in the monoclinic space group P21/n with a = 163537(2), b = 133981(3), c = 352277(7) A, β = 91284(1)°, and Z = 8 molecules per unit cell, and complex 5 in P21/n with a = 106445(8), b = 26412(3), c = 15781(2) A, β = 107996(7)°, and Z = 4 In compounds 3 and 5, the palladium ions are in a distorted square planar environment They are closely related, having two sulfur atoms of two thiosaccharinate anions, and two phosphorus atoms of one molecule of dppm or dppe, respectively, bonded to the PdII atom The molecular structure of complex 3 is the first reported for a mononuclear PdII-dppm-thionate system
14 citations
TL;DR: In this paper, the crystal and molecular structure of dilapacholate aqua(dimethylformamide)nickel(II) was determined by X-ray diffraction and the structure was solved from 5094 reflections with I>2σ(I) and refined by full matrix least-square to an agreement R 1-factor of 0.0564.
Abstract: The crystal and molecular structure of dilapacholateaqua(dimethylformamide)nickel(II) was determined by X-ray diffraction. It crystallizes in the triclinic space group P 1 with a = 9.8671(9) A, b = 10.654(1) A, c = 15.289(2) A, α = 86.98(1)°, β = 79.32(1)°, γ = 87.031(8)°, and Z = two molecules per unit cell. The structure was solved from 5094 reflections with I>2σ(I) and refined by full matrix least-square to an agreement R 1-factor of 0.0564. The nickel(II) is in a NiO6 octahedral environment, cis coordinated to two lapacholate anions through their adjacent carbonyl [Ni–O distances of 2.075(2) and 2.066(2) A], and phenyl oxygens [Ni–O lengths of 2.011(2) and 2.021(2) A], and to a water [d(Ni–Ow) = 2.073(2) A] and a DMF [d(Ni–O) = 2.076(2) A] at axial positions. Some physicochemical and spectroscopic properties of the complex are also reported.
9 citations
TL;DR: The thermodynamics of complexation of 1 and these cations provide a quantitative assessment of the selective behavior of this ligand for ions of environmental relevance.
Abstract: A thermodynamic study involving 7-nitro-1,3,5-triaza adamantane, 1, and its interaction with metal cations in nonaqueous media is first reported. Solubility data of 1 in various solvents were used to derive the standard Gibbs energies of solution, DeltaG(s)o in these solvents. The effect of solvation in the different media was assessed from the Gibbs energy of transfer taking acetonitrile as a reference solvent. 1H NMR studies of the interaction of 1 and metal cations were carried out in CD3CN and CD3OD and the data are reported. Conductance measurements revealed that this ligand forms lead(II) or zinc complexes of 1:1 stoichiometry in acetonitrile. It also revealed a stoichiometry of two molecules of 1 per mercury(II) and two cadmium (II) ions per molecule of 1. The addition of silver salt to 1 led to the precipitation of the silver-1 complex which was isolated and characterized by X-ray crystallography. At variance with conductance measurements in solution, in the solid state the X-ray structure shows a 1:1 stoichiometry in the Hg(II) complex. The thermodynamics of complexation of 1 and these cations provide a quantitative assessment of the selective behavior of this ligand for ions of environmental relevance.
9 citations
TL;DR: In this article, a new compound acenaphtho [5,6-b]-2,3-dihydropyrazine was synthesized and characterized, which was followed by cyclic voltammetry and NMR spectroscopy which, in some cases, allowed the detection of the thiadiazolidine intermediate.
8 citations
TL;DR: In this article, the structure of bisopropoxy(thiocarbonyl)sulfide, [(CH 3 ) 2 CHOC(S)] 2 S, have been studied by vibrational spectroscopy (IR and Raman) and quantum chemical calculations.
TL;DR: In this article, the ionic crystals are further stabilized by an extensive H-bonding network, which links the anions and cations into an infinite three-dimensional supramolecular assembly.
Abstract: 1 with 2 molecules per unit cell, and 2 in the monoclinic space group P21/a with Z = 4. The saccharinate moiety is planar in both compounds presenting bonding characteristics comparable to those found in other saccharinate salts. The ionic crystals are further stabilized by an extensive H-bonding network, which links the anions and cations into an infinite three-dimensional supramolecular assembly. The FTIR spectra of the adducts are briefly discussed in comparison with those of the constituent molecules.