Search Results

You are looking at 1 - 8 of 8 items for :

  • "cadmium complexes" x
  • Refine by Access: All Content x
Clear All

Abstract  

New cadmium complexes of the salicylidene-2-amino-thiophenol (I) and 3-methoxysalicylidene-2-amino-thiophenol (II) Schiff bases have been prepared and characterized by elemental analyses, IR, 1H-NMR spectra, conductimetric and thermogravimetric analyses. The results suggested that the Schiff bases are bivalent anions with tridentate ONS donors derived from the phenolic oxygen azomethine nitrogen and thiophenolic sulphur. The formulae are found to be [MLH2O] and [ML2]for the 1:1 and 1:2 non-electrolytic complexes, respectively. The thermal decomposition of the complexes follows first order kinetics and the thermodynamic parameters of the decomposition are reported.

Restricted access

Summary The paper presents the conditions of synthesis and results in the characterization (chemical analysis, thermal analysis, kinetic of decomposition) for two complex compounds of cadmium: [Cd(S2O3)phen]×H2O and [Cd(S2O3)phen2]×2H2O. The obtained complexes were used as precursors for complex sulfides by controlled thermal decomposition. On the basis of transmission electron microscopy (TEM) the complex sulfides may be included in the nanomaterials category.

Restricted access

Abstract  

Hydrazinium metal ethylenediaminetetraacetate complexes of molecular formula (N2H5)2[Mg(edta)·H2O], (N2H5)3[Mn(edta)··H2O](NO3)·H2O, N2H5[Fe(edta)·H2O], N2H5[Cu(Hedta)·H2O] and N2H5[Cd(Hedta)·H2O]·H2O have been synthesized and characterized by elemental and chemical analysis, conductivity and magnetic measurements and spectroscopic techniques. The thermal behaviour of these complexes has been studied by thermogravimetry and differential thermal analysis. The data set provided by the simultaneous TG-DTA curves of the complexes shows the occurrence of three or four consecutive steps such as dehydration, ligand pyrolysis and formation of metal oxides. X-ray powder diffraction patterns of copper and cadmium complexes show that they are not isomorphous. These studies suggest seven coordination for Mg,Mn, Fe complexes and six coordination for Cu and Cd derivatives.

Restricted access

Abstract  

The iodide complexes of transition metals with 1,2-diimidazoloethane (DIE) of the general formula MLI2, (M=Cu(II), Hg(II), Cd(II); L=1,2-diimidazoloethane) were prepared and studied by means of thermogravimetry (TG/DTG) and differential thermal analysis (DTA) techniques. Their compositions were investigated by elemental analysis in order to ensure their purity and structural elucidations were based on conductivity measurements, room temperature magnetic measurements, proton NMR, XRD and IR spectra. Thermal decomposition of these distorted tetrahedral complexes and the ligand took place in two distinct steps upon heating up to 800�C, with the loss of inorganic and organic fragments. The thermal degradation of all the complexes (except for cadmium complex) in static air atmosphere started at temperatures lower than those observed for the free ligand pyrolysis. The composition of intermediates formed during degradation was confirmed by microanalysis and IR spectroscopy. The residues after heating above 740�C corresponded to metal oxide except for Hg(II) complex, which behaved differently. It was found on the basis of thermal analysis that thermal stability of the complexes increased in the following sequence: Hg(II)<Cu(II)<Cd(II).

Restricted access

Abstract  

Behavior of cadmium(II) in aqueous solutions irradiated by accelerated electrons was studied. A concentration of 8.8 × 10−4 mol L−1 of cadmium dissolved from Cd(NO3)2 requires dose of 15 kGy to be effectively removed from the system containing 1 × 10−2 mol L−1 of HCOOK as a scavenger of OH radicals. The positive effect of deaeration with N2O or N2 was observed in the range of lower doses. The addition of solid modifiers (bentonite, active carbon, zeolite, Cu2O, NiO, TiO2 and CuO) reduced the effectivity of radiation removal of cadmium. Product of irradiation is CdCO3. On the contrary, in the system with cadmium dissolved from CdCl2 radiation reduction takes place. Systems contained organic complexants (ethylene diamine tetraacetic acid–EDTA, citric acid) were also studied. The solutions of Cd(NO3)2 containing initial concentration 2.37 × 10−4 mol L−1 of CdII were mixed with 3 × 10−4 mol L−1 EDTA. In this system the efficient degradation proceeds up to 90% at a dose of 45 kGy with addition of 5 × 10−3 mol L−1 carbonate (pH 10.5). The product of irradiation is CdCO3. The presence of 1 × 10−2 mol L−1 of HCOOK in the solution is necessary for radiation removal of cadmium complexed with citric acid (1 × 10−3 mol L−1) at pH 8. With increasing concentration of HCOOK (up to 5 × 10−2 mol L−1) decreases the pH value necessary for the radiation induced precipitation of cadmium. The best result was obtained in the system containing zeolite as a solid modifier.

Restricted access

the solution (about 4–5 days), orange-pink plates were collected by filtration and dried in vacuum box. Yield 32%. Preparation of cadmium complex ( 3 ) 4-CHO-5-MeIm (0.221 g, 2.0 mmol) dissolved in 20 mL of

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: Barbara Barszcz, Joanna Masternak, Maciej Hodorowicz, and Agnieszka Jabłońska-Wawrzycka

. Crystal structure determination Diffraction intensity data for single crystal of new cadmium complex were collected at room temperature on a KappaCCD (Nonius) diffractometer with graphite-monochromated MoK α radiation (λ = 0.71073 Å

Open access

bidentate ligands . J Therm Anal Calorim . 2001 ; 66 : 379 – 386 . 10.1023/A:1013174330335 . 16. Soliman , AA . Thermogravimetric and spectroscopic studies on cadmium complexes with two

Open access