scholarly journals Spectrophotometric Microdetermination of Thorium(IV) and Uranium(VI) with Chrome Azurol-S in Presence of Cationic Surfactant

2011 ◽  
Vol 8 (3) ◽  
pp. 1132-1141 ◽  
Author(s):  
A. B. Upase ◽  
A. B. Zade ◽  
P. P. Kalbende

Cationic surfactant, cetyldimethylethylammonium bromide (CDMEAB), sensitize the color reactions of Th(IV) and U(VI) with chrome azurol-S(CRAS). Formation of water soluble deeply colored ternary complexes of metal ions show large bathochromic shift. Same stoichiometric composition of ternary complexes with 1:2:4 molar ratio (M-CRAS-CDMEAB) have been observed for both the metal ions and are responsible for enhancement in molar absorptivities and sensitivities at shifted wavelength. The ternary complexes of thorium(IV) and uranium(VI) exhibit absorption maxima at 640 and 620 nm with molar absorptivities 85500 and 69600 L.mol-1.cm-2respectively. Beer’s law were obeyed in concentration range 0.12-0.185 ppm for Th(IV) and 0.13-0.162 ppm for U(VI) in presence of CDMEAB. Conditional formation constants and various analytical parameters have been evaluated and compared the results of binary and ternary complexes. Enhancement in the molar absorptivities in presence of CDMEAB clearly indicated the usefulness of these colored reactions for microdetermination.

2009 ◽  
Vol 6 (s1) ◽  
pp. S117-S122 ◽  
Author(s):  
Shaesta Quyoom ◽  
Badr-Ud-Din Khan

The formation constants of the binary 1:1 and 1:2 complexes of Cu(II), Zn(II), Cd(II), Hg(II), and Pb(II) withN-acetylcysteine (NAC) and 1:1:1 ternary complexes of the said metal ions with NAC as a primary ligand and some biologically important amino acids as secondary ligands have been determined potentiometrically in aqueous medium. Acid dissociation constants of the ligands used and the formation constants of the binary and the ternary complexes were determined at 25 °C and in ionic strength I=0.1 mol dm-3(KNO3).The formation constants of the 1:1 complexes were found to be higher than 1:2 complexes and the metal ions follow the order Hg(II) >Cu(II) >Cd(II) >Zn(II). In addition UV-spectral studies of the NAC-Metal (II) complexes have also been conducted at appropriate pH values to give further information about the structural nature of NAC- Metal (II) complexes in aqueous medium.


2011 ◽  
Vol 8 (3) ◽  
pp. 1264-1274 ◽  
Author(s):  
A. S. Dhepe ◽  
A. B. Zade

Study of coordination compounds of lanthanide elements has received a great attention due to growing applications in science and technology. Number of chromogenic reagents form water soluble colored complexes with lanthanides. Eriochrome cyanine R (ECR) a member of triphenylmethane type of dye has been reported to form green colored complexes with lanthanides and has been used for microdetermination of these metal ions. Addition of cationic surfactant, Cetylpyridinium bromide (CPB), a cationic surfactant sensitizes the color reactions of Gd(III), Tb(III), Dy(III), Ho(III) and Lu(III) with ECR. Formation of water soluble, highly colored ternary complexes with a considerable bathochromic shift of about 50 nm in presence of surfactant has been observed. Optimum reaction conditions and other analytical parameters were also evaluated. Stoichiometric ratio 1:3:3 of Ln: ECR: CPB are responsible for the observed rise in molar absorptivity and sensitivity. Beer’s law was obeyed between 0.50 to 13.00 ppm. Effective photometric range and molar absorptivity of these ternary complexes have been calculated. Effect of some common interfering ions on determination of these lanthanide metal ions was studied. A simple, rapid and highly sensitive spectrophotometeric method has been proposed for the determination of metal ions understudy.


Author(s):  
M. A. Oladipo ◽  
K. T. Ishola ◽  
T. A. Ajayeoba

The formation constants of binary and ternary complexes of Thiobarbituric acid as primary ligand and L-tyrosine and L-histidine as secondary ligands have been examined in 40% (v/v) ethanol-water mixture at 27oC and 35oC and at ionic strength of 0.02 NaNO3 by potentiometric method. The ligands formed 1:1 binary complexes with the metal ions. The primary and secondary ligands simultaneously coordinated to the metal ions to form 1:1:1 ternary complexes. The difference in stability constants of binary and ternary complexes were determined by DlogK and RS%. Ternary complexes exhibited enhanced stability than the binary complexes. The stability of the complexes decrease with increase in temperature. The thermodynamic parameters such as Gibb’s free energy change (ΔG), entropy change (ΔS) and enthalpy change (ΔH) accompany the interactions were evaluated. The interactions were found to be spontaneous, exothermic, and entropically favoured.


2012 ◽  
Vol 9 (4) ◽  
pp. 2394-2406 ◽  
Author(s):  
Anil B. Zade ◽  
Pawan P. Kalbende ◽  
Mayuri S. Umekar ◽  
Gajanan W. Belsare

Cetyldimethylethylammonium bromide, a cationic surfactant has been used to decolorize eriochromeazurol B, an anionic triphenylmethane type of dye. Addition of specific lanthanide metal ion to this decolorized solution resulted into intense colored stable ternary complex with large bathochromic shift from 540 nm (binary complex) to 650 nm (ternary complex) with increase in absorbance values at shifted wavelength. CDMEAB thus decreases the color intensity of ECAB and increases the absorbance value of ternary complexes. This two fold advantage resulted into enhancement in molar absorptivities and sensitivities at shifted wavelength of ternary complexes with stoichiometric composition 1:(1:3)2, [Ln : (R:S)] for all lanthanides understudy namely yttrium, neodymium, europium, terbium and ytterbium. The ternary complexes at pH 6.0 exhibited absorption maxima at 650 nm with molar absorptivities 69000 L.mol-1.cm-2for Y(III), 66000 L.mol-1.cm-2for Nd(III), 69000 L.mol-1.cm-2for Eu(III), 64000 L.mol-1.cm-2for Tb(III), 70000 L.mol-1.cm-2for Yb(III). Beer's law were obeyed in concentration range 0.11-0.94, 0.19-1.53, 0.2-1.41, 0.21-1.69 and 0.23-1.11 ppm for Y(III), Nd(III), Eu(III), Tb(III) and Yb(III) respectively. Conditional formation constants and various analytical parameters have been evaluated and compared the results of newly formed ternary complexes with binary complexes. Finally newly suggested modified method have been recommended for the microdetermination of lanthanides understudy.


1993 ◽  
Vol 58 (5) ◽  
pp. 1103-1108 ◽  
Author(s):  
Mohamed M. Shoukry ◽  
Eman M. Shoukry

The formation constants of the binary and ternary complexes of palladium(II) with diethylenetriamine and amino acids as ligands have been determined potentiometrically at 25 °C in 0.1 M NaNO3 solution. The relative stability of each ternary complex was compared with that of the corresponding binary complexes in terms of ∆logK values. The mode of chelation was ascertained by conductivity measurements.


1992 ◽  
Vol 70 (3) ◽  
pp. 877-879
Author(s):  
Refat Abdel-Hamid ◽  
Mohamed T. El-Haty

Binary and ternary complexes of Cd(II) with salicylidene tris(hydroxymethyl) methylamine and chloride ion at 298 K were studied polarographically at I = 0.1 mol dm−3 NaClO4 in 30% (v/v) DMF – aqueous medium at pH 10.2. The overall formation constants were found to be, for the binary system, log β1 = 3.55 ± 0.03 and log β2 = 5.40 ± 0.07 and, for the ternary one, log β11 = 7.64 ± 0.06 and log β12 = 9.56 ± 0.06. Keywords: formation constants, binary and ternary complexes of Cd(II).


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