Authors:I. Pastre, I. do Nascimento Oliveira, A. Moitinho, G. de Souza, E. Ionashiro, and F. Fertonani
The composite montmorillonite-8-hydroxyquinoline (Swy-1-8-HQ) was prepared by two different processes and studied by using
thermogravimetric analysis (TG/DTG and DSC), as well as helpful techniques as fluorescence in the UV-visible region and X-ray
diffraction. The composites developed fluorescent appearance, however with quantum poor efficiency and they exhibited distinct
TG and DSC thermal behavior. The fluorescence data of spectra associated to the TG/DT curves allowed to suggest that the 8-HQ
was present in the composites in two different circumstances: 1 - intercalated in the interlayer spaces (Swy-1-8-HQ2), rigidly
associated to the substrate feasible as a monolayer with the aromatic rings parallel to the silica layer; and/or, 2 - adsorbed
on the surface (Swy-1-8-HQ1), either as a bilayer formation or tilting of the molecules to the silicate layer sheet. All results
confirmed above are in agreement with X-ray diffraction patterns, once the interlayer space increases when 8-HQ is incorporated.
The experimental results confirm the formation of the composites in agreement with the method used in the preparation.
Formation constants (logKMALMA) of the mixed complexes of the type M–A–L (where M=Mn(II), Co(II), Ni(II), Cu(II), Ce(III), Th(IV), and UO2(II); A=oxine and L=sulphamerazine or sulphadiazine) have been determined pH-metrically in 60% (v/v) ethanol–water mixture at 25°C and constant ionic strength (μ=0.1 M NaCl). The mode of chelation was ascertained by conductivity
measurements. The stability sequence with respect to metal ions have been found to be Cu(II)>Ni(II)>Co(II)>Mn(II) and Th(IV)>UO2(II)>Ce(III). CuAL ternary solid complexes have been prepared and characterized on the basis of elemental analysis and IR-spectroscopy.
The thermal degradations of the prepared complexes are discussed in an attempt to assign the intermediate compounds formed.
Authors:B. S. Garg, R. Dixit, A. L. Singh, and R. K. Sharma
Chromium(III) complexes of the type Cr(A)(A′)2, Cr(A)2(A′) and Cr(A)3 have been prepared (whereA is either piperidyldithiocarbamate or morpholyldithiocarbamate andA′ is glycine or oxine or acetylacetone moiety). The mixed ligand complexes have been charac terized by elemental analyses, magnetic susceptibility measurements and thermal studies. The complexes show magnetic moment in the range of 3.5–4.3 B.M. which corresponds to three unpaired electrons. TG studies have also been carried out, in order to study the mode of decomposition of the complexes and to evaluate various kinetic parameters.
Synergistic extraction of Co(II) with 8-hydroxyquinoline (Hq)/decanoic acid [(HR)2] solution mixtures in benzene and chloroform was carried out at 25°C. The aqueous ionic strength and the total concentration of cobalt(II) were 0.1 (NaCl) and 1·10–5–1·10–3M, respectively. The synergistic effect is interpreted by the formation of the mixed ligand ion-pair complexes: [(Coq(Hq)2(HR))+, R–] and [(Coq(Hq)2(HR)3)+, R–] in benzene and chloroform, respectively.
Recently, a new type of resinous adsorbent has been developed as an effective adsorbent for a number of organic materials.
The adsorbent has macro-reticular structure and no ion-exchange capacity.
This paper deals with the adsorption of typical fission products and induced radionuclides on Amberlite XAD-2, with 8-hydroxyquinoline
(oxine) as the organic reagent.
It was found that60Co,59Fe,144Ce,95Zr, and106Ru were transferred to the adsorbent phase from various solutions, when oxinates of the nuclides were formed in the solutions.
Without oxine, most of the nuclides were not adsorbed on the adsorbent.137Cs and85Sr were not adsorbed on XAD-2 with or without oxine.
The Mössbauer spectrum of ferric oxinate exhibits and asymmetric quadrupole doublet. The modification of the dynamic Mössbauer parameters (to the equal values for each line) following the irradiation, was explained by the internal oxine ligands rotation inside of the octahedral coordination.
A radiochemical solvent extraction method has been developed for the determination of Cr(III) using51Cr tracer. It is based on the complexation of Cr(III) with 8-hydroxyquinoline (oxine) and acetylacetone as mixed ligands at pH 3.8 and extraction in chloroform. Effect of various parameters such as pH, time of equilibration, nature of solvent, quantitative nature, effect of diverse ions has been studied. The method can be used up to 200 ng of Cr.
Neutron activation is suggested for the determination of Pt, Au, Hg, Sc, Zn and Sn in high purity gallium. Pt, Hg and Au are
reduced to metals, gallium is extracted and then Sc, Zn, and Sn are separated on Dowex 1×8 ion exhanger. All components except
Sn are determined by substoichiometric methods in the form of chelate complexes. Sn is extracted with oxine into chloroform,
and the chemical yield measured by spectrophotometry.
The photoproduct of octacyanomolybdate(IV) and -tungstate(IV) with ethylenediamine and triethylenetetramine give complexes of the type K3[Mo(O2)(O)(OH)(C9H7ON)]·3C9H7ON I, K2[W(O2)(O) (C9H7ON)3] II and K3[Mo(CN)3(OH)4(C9H7ON)]·2C9H7ON·3H2O III with 8-quinolinol (oxine). The IR spectra of the complex III shows the presence ofv(CN) peaks in the range 2047–2108 cm−1 and oxine groupv(C-O) in the complex I, II and III in the range of 1100–1150 cm−1. The lower region of IR spectra shows the M=O stretching while the higher thev(N-H) andv(OH). Thermal studies show the removal of uncoordinated water at 131‡C from complex III. The decomposition of complexes I and II start from 150 and 212‡C respectively. Oxine and cyano molecules were removed in stages at higher temperatures. The final product of the thermal decomposition was oxide which was of polymeric nature. The kinetic parameters viz. order of reaction ‘n’ and activation energy ‘E’ were determined by different methods.