Indian Journal of Chemistry

Sect. A: Inorganic, Bio-inorganic, Physical, Theoretical & Analytical

Total visitors: 2,011  since 14-06-05

 

VOLUME 44A

NUMBER 6

JUNE 2005

CONTENTS

Papers

 

1127

 

Chemistry of a family of osmium(II) metallacycles incorporating isonitrile coordination

 

 

 

 

 

 

 

Bikash Kumar Panda & Animesh Chakravorty*

 

 

 

The first example of a structurally characterized cyclometallated osmium(II) isonitrile complex showing the effect of Os-CNBut back-bonding on spectra and metal redox is reported. Due to disparity in bond strengths, the complex is unreactive towards CNBut in contrast to its ruthenium analogue.

 

 

1133

 

Synthesis and characterization of polyaniline salts with phenoxy acetic acids by emulsion polymerization

 

 

 

 

 

 

 

B Veerendra & D N Sathyanarayana*

 

 

 

Polyaniline salts have been synthesized by chemical oxidative polymerization of aniline. These polyaniline salts have the desirable property of high solubility for processibility in solvents such as DMF, DMSO and a mixture of CHCl3 and acetone and fairly good conductivity of ~ 3.0 10-3 S cm-1. The variations in solubility, conductivity and morphology with the protonating strength of the dopants are examined.

 

 

1139

 

Synthesis and characterization of organoindium complexes derived from internally functionalized anionic ligands

 

 

 

 

 

 

Shamik Ghosal, Dimple P Dutta, Nisha P Kushwah & Vimal K Jain*

 

 

 

 

 

1144

 

Synthesis and characterization of 1D complexes
[Na(DC18C6-A)]2[M(i-mnt)2] (M = Ni, Pd, Pt)

 

 

 

 

 

 

 

 

 

Feng-Ying Dong, Jian-Min Dou*, Xi-Ke Gao,

Da-Cheng Li & Da-Qi Wang

 

 

 

 

1151

 

Interaction of calf thymus DNA with new asymmetric copper(II) N,N-ethane bridged N2S2 macrocycle

 

 

 

 

 

 

 

 

 

 

Shamima Parveen & Farukh Arjmand*

 

 

 

Novel asymmetric metalated Cu(II), Ni(II) double decker N,N-ethane bridged N2S2 macrocycles have been synthesized. The complexes have square-planar geometry and are ionic in nature. On interaction with CT-DNA, the absorption spectra exhibit a shift in wavelength with a steep decrease in absorbance indicating strong binding of
CT-DNA with the Cu(II) complex. The shift in formal potential (E0) after the interaction with CT-DNA clearly indicates the binding of Cu(II) complex to CT-DNA. Besides this, the ratio of anodic to cathodic peak currents Ipa/Ipc is ~0.8 for the free Cu(II) complex while for DNA bound metal complex, the ratio decreases to (0.5) suggesting that CT-DNA is bound strongly to the Cu(II) complex.

 

1159

 

Synthesis, reactivity and physico-chemical studies of some novel mixed ligand complexes of copper(II)

 

 

 

 

 

 

 

 

 

 

R K Dubey*, C M Mishra & A N Mishra

 

 

 

 

1165

 

Solid acids in liquid phase esterification

 

 

 

 

 

 

 

N Nagaraju* & S Z Mohamed Shamshuddin

 

 

 

Catalytic activity of different protonated zeolites such as HY, Hβ, HZSM5 and sulfated oxides such as SO42-/Al2O3, SO42-/SiO2­, SO42-/ZrO2 in the esterification of propionic acid with various alcohols (C1-C5) over solid acids as catalysts has been investigated. All the catalysts have been found to be active towards the formation of propionate esters as the major reaction product. A good correlation between the concentration of acid sites and the catalytic activity of the catalysts has been observed.

 

 

1171

 

Theoretical estimation of heat capacity, density and thermal expansivity of liquid metal alloys

 

 

 

 

 

J D Pandey*, N K Soni, R K Mishra, K K Tiwari & D K Dwivedi

 

 

 

Theoretical formulation based on Florys statistical theory  has been made for estimating heat capacity, density and thermal expansivity of liquid metal alloys of Na+Cs and K+Rb at three different temperatures and at various compositions. Theoretically estimated values are in good agreement with the observed values reported in literature.

 

1176

 

Electrosynthesis, photoelectrochemical and corrosion studies on (CdIn) Se, (CdGa) Se thin films

 

 

 

 

 

R K Pathak* & Sandhya Sankwa

 

 

 

Electrosynthesis of indium and gallium containing CdSe thin films on titanium substrate by electrochemical co-deposition method has been studied using aqueous electrolytic bath at room temperature. The incorporation of indium and gallium during deposition of CdSe thin films enhances photoactivity and reduces corrosion rate. EDAX and SEM analysis have been used for compositional and surface characterisation of the films.

 

Notes

 

1183

 

Acoustical study of substituted azoles in
N,N-dimethylformamide at different temperatures

 

 

 

 

 

 

 

 

Deepali P Gulwade*, M L Narwade & S A Wadhal

 

 

 

Ultrasonic velocity and density measurements of 2-(5-amino-[1,3,4]thiadiazol-2-yl)-phenol, 2-(5-mercapto-[1,3,4] oxadiazol-2-yl)-phenol), 2-(5-mercapto-[1,3,4]thiadiazol-2-yl)-phenol), 2-[1H-benzimidazol-2-yl]-5-phenyl-1H-pyrazol-3-yl]-4-methyl phenol and 3-(2-hydroxy-5-methyl-phenyl-pyrazol-1-yl]-pyridin-4-yl-methanone in N,N-dimethylformamide  are reported at 303, 308, 313, 318 and 323 K in the solute concentration of 110-2 mol dm-3.

 

 

1186

 

Studies on optical and electrical properties of synthesized polycrystalline CdMoO4 and PbMoO4

 

 

 

 

 

P K Pandey*, N S Bhave & R B Kharat

 

 

 

Molybdates of Cd(II) and Pb(II) have been synthesized by chemical route. The formation of CdMoO4 and PbMoO4 has been confirmed by chemical analysis and powder XRD studies. Single-phase nature and purity of the molybdates have been ascertained by matching their XRD data with the JCPDS data file.

 

 

1191

 

Kinetics and mechanism of the interaction of
N donor ligands with iodomethyl(aquo)cobaloxime

 

 

 

 

 

 

 

N Navaneetha & S Satyanarayana*

 

 

 

1197

 

Enrichment of indium from aqueous solution using functionalized sorbent

 

 

 

 

 

 

Saima Q Memon*, Najma Memon, M I Bhanger & M Y Khuhawar

 

 

 

The styrene-divinylbenzene-based polymeric material containing phthalic acid as chelating agent has been used to concentrate ultra trace amounts of indium ions in aqueous solutions. Sorption behavior of In(III) ions under static and dynamic conditions onto the new synthetic resin is also reported.

 

 

1203

 

Ultrasonic studies of substituted isoxazoles and pyrazolines in dioxane and dioxane-water mixtures at different temperatures

 

 

 

 

 

 

Shashikant A Ikhe*& M L Narwade

 

 

 

Ultrasonic velocities and densities of 3-(2-hydroxy-3-bromo-5-methylphenyl)-5-phenyl isoxazole, 1-phenyl-3-
(2-hydroxy-3-bromo-5-methylphenyl)-5-(4-methoxyphenyl) pyrazoline, in dioxane and different percentages of dioxane-water mixtures at different temperatures (303, 308, 313, 318, 323 K,
0.1 K) have been evaluated at 0.01 M concentration.

1206

 

Chelation ion-exchange properties of
2,2
-dihydroxybiphenyl-urea-formaldehyde (2:1:3) resin

 

 

 

 

 

 

Manjusha M Jadhao, L J Paliwal & N S Bhave*

 

 

 

 

 

1211

 

Determination of cadmium(II), copper(II) and zinc(II) in water samples by flame atomic absorption spectrometry after cloud point extraction

 

 

 

 

Farzaneh Shemirani*, Shiva Dehghan Abkenar & Mohammad Reza Jamali

 

 

 

A preconcentration method for determination of low concentrations of Cd(II), Cu(II), and Zn(II) in water, using cloud point extraction is described. The analytes in the initial aqueous solution have been complexed with
8-hydroxyquinoline, with 0.06% (w/v) Triton X-114 added as surfactant.

 

 

1215

 

Catalytic kinetic spectrophotometric determination of palladium(II) and its application to the determination of traces of propylthiouracil

 

 

 

 

 

A Jabbari, M Barzegar* & M Mohammadi

 

 

 

The catalytic-kinetic method has been proposed for the determination of palladium(II) based on its catalytic effect on the reaction of crystal violet with hypophosphite. The reaction has been monitored spectrophotometrically at
590 nm over the range 0.071-2.850 ppm of Pd(II).

 

 

Authors for correspondence are indicated by (*)

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1127-1132

 

Chemistry of a family of osmium(II) metallacycles incorporating isonitrile coordination

Bikash Kumar Panda & Animesh Chakravorty*

Received 18 February 2005; revised 23 March 2005

The reaction of Os(RL)(PPh3)2(CO)Br (3) with CNBut in dichloromethane solution has furnished the cationic complex [Os(RL)(PPh3)2(CO)(CNBut)]+ isolated as PF6-salt, 4 which behaves as a 1:1 electrolyte in acetone solution (RL is C6H2O-2-CHNHC6H4R(p)-3-Me-5 and R is Me, OMe and Cl). The presence of significant Os-CNBut back-bonding in 4 is reflected in the blue shift of both the MLCT transition maximum (~500 nm) and CO stretching frequency (~1930 cm-1) compared to those in 3 (~550 nm and ~1870 cm-1, respectively). For the same reason, the OsIII/OsII reduction potential (~0.8 V vs. SCE) in 4 is ~100 mV higher than those in 3. The complex 42CH2Cl2 (R = Me) represents the first example of a structurally characterized cyclometallated osmium(II) isonitrile system. In the distorted octahedral OsC3OP2 coordination sphere of 42CH2Cl2 (R = Me), the Os-P, Os-CO and Os-O bond lengths are closely similar to those in a analogue of 3. Due to the trans influence of the CNBut ligand, the Os-C(aryl) bond is however lengthened by ~0.15 in 42CH2Cl2 (R = Me). The type 3 complexes stand in strong contrast to the corresponding ruthenium system, which undergoes halide substitution as well as insertion into the Ru-O bond upon treatment with CNBut. This happens because the Os-O bond (2.166(6) ) is stronger than the Ru-O bond (2.235(4) ).

IPC Code: Int. Cl.7 C07F15/00

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1133-1138

 

Synthesis and characterization of polyaniline salts with phenoxy acetic acids by emulsion polymerization

B Veerendra & D N Sathyanarayana*

Received 20 August 2004; revised 25 February 2005

Polyaniline salts have been synthesized by chemical oxidative polymerization of aniline in the presence of phenoxy acetic acid and its two derivatives using emulsion method at room temperature and characterized by different techniques such as infrared, 1H and 13C NMR, UV-visible spectroscopy, SEM, wide angle X-ray diffractograms and conductivity measurements. These polyaniline salts have the desirable property of high solubility for processibility in solvents such as DMF, DMSO and a mixture of CHCl3 and acetone and they exhibit fairly good conductivity of ~ 3.0 10-3 S cm-1. The variations in solubility, conductivity and morphology with the protonating strength of the dopants are examined.

IPC Code: Int. Cl.7 C08F2/22

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1139-1143

 

Synthesis and characterization of organoindium complexes derived from internally functionalized anionic ligands

Shamik Ghosal, Dimple P Dutta, Nisha P Kushwah & Vimal K Jain*

Received 18 February 2005; accepted 6 April 2005

Reactions of triorganoindium etherate with protic ligands in benzene at room temperature have afforded diorganoindium complexes of the type, [R2In(L)]n [R = Me, Et; L = (C5H4N)CH2O-, (C5H4N)CH2CH2O-; 2-MeOC6H4O-; C6H5CO2-; 2-MeOC6H4CO2-; 2-(C5H4N)CO2-; 2-(C9H6N)CO2-; 2-(C4H3O)-CO2-]. These complexes have been characterized by indium analysis, IR, NMR (1H, 13C{1H}) and mass spectral data. The mass spectra reveal that these complexes are associated in the solid state. The complex Et2In(O2C-C9H6N) shows photoluminescence on excitation with 370 nm radiation.

IPC Code: Int. Cl.7 C07F5/00

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1144-1150

 

Synthesis and characterization of 1D complexes [Na(DC18C6-A)]2[M(i-mnt)2] (M = Ni, Pd, Pt)

Feng-Ying p Wang< Da-Qi & Li Da-Cheng Gao, Xi-Ke Dou*, Jian-Min Dong

Received 18 November 2004; revised 11 March 2005

Three inorganic-organic hybrid complexes [Na(DC18C6-A)]2[M(i-mnt)2] (DC18C6-A = cis-syn-cis-dicyclohexyl-18-crown-6, isomer A; M = Ni, 1; Pd, 2; Pt, 3; i-mnt = 1,1-dicyanoethene-2,2-dithiolate, isomaleonitriledithiolate) were synthesized by the reactions of dicyclohexyl-18-crown-6 with Na2(i-mnt) and NiCl2, PdCl2 and Na2PtCl4, respectively, and characterized by elementary analysis, FT-IR and UV-vis spectroscopy. The crystal structures were determined by X-ray single crystal diffraction. Complexes 1-3 all crystallize triclinic, space group P ī with crystallographic data: 1, a = 10.19(4) , b = 11.92(4) , c = 12.58(5) , a = 102.21(6), b = 108.89(5), g = 99.70(6), V = 1366.5(9) 3, Z = 1, Dcalcd = 1.373 g/cm3, F(000) = 598, R1 = 0.0440, wR2 = 0.0982. 2, a = 10.18(6) , b = 11.99(7) , c = 12.60(7) , a = 102.79(10), b = 109.12(3), g = 99.02(10), V = 1367.6(13) 3, Z = 1, Dcalcd = 1.430 g/cm3, F(000) = 616, R1 = 0.0574, wR2 = 0.1204 and 3, a = 10.23(15) , b = 12.02(18) , c = 12.64(19) , a = 102.87(16), b = 109.19(2), g = 99.14(2), V = 1384(4) 3, Z = 1, Dcalcd = 1.519 g/cm3, F(000) = 648, R1 = 0.0316, wR2 = 0.0587. Three complexes are isomorphous and all display an infinite 1D chain-like structure formed by [Na(DC18C6-A)]+ complex cations and [M(i-mnt)2]2- (M= Ni, Pd, Pt) complex anions through N-Na-N interactions.

IPC Code: Int. Cl7. C07F15/04, C07F15/00

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1151-1158

 

Interaction of calf thymus DNA with new asymmetric copper(II) N,N-ethane bridged N2S2 macrocycle

Shamima Parveen & Farukh Arjmand*

Received 10 October 2003; accepted 2 April 2005

Novel asymmetric metalated Cu(II), Ni(II) double decker N,N-ethane bridged N2S2 macrocycles have been synthesized. Structure elucidation of the complexes has been done on the basis of elemental analysis, IR, UV-vis, EPR, conductance measurements, 1H NMR and 13C NMR spectroscopy. All the spectroscopic data indicate that the metal ions attain square-planar geometry and are ionic in nature. The kinetic studies have been carried out with calf thymus DNA (CT-DNA) to ascertain the metal-DNA interaction by spectrophotometric method at the lmax (446 nm) of Cu(II) complex at 301C. On interaction with CT-DNA, the absorption spectra exhibit a shift in wavelength, and also a steep decrease in absorbance which clearly indicates strong binding of CT-DNA with the Cu(II) complex. The rate constants (kobs) have been calculated under pseudo-first-order conditions and the plot of kobs versus [DNA] gives a straight line. The electrochemistry of DNA-metal complex interaction has been carried out in H2O/DMSO (95:5) solution at different scan rates. The shift in formal potential (E0) after the interaction with CT-DNA clearly indicates the binding of Cu(II) complex to CT-DNA. Besides this, the ratio of anodic to cathodic peak currents Ipa/Ipc is ~0.8 for the free Cu(II) complex while for DNA bound metal complex, the ratio decreases to (0.5) suggesting that CT-DNA is bound strongly to the Cu(II) complex.

IPC Code: Int. Cl.7 C07F1/08

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1159-1164

 

Synthesis, reactivity and physico-chemical studies of some novel mixed ligand complexes of copper(II)

 

R K Dubey*, & A N Mishra

Received 13 September 2004; Revised 18 March 2005

Some copper(II) complexes having general formula, [(m-Cl)2Cu2{h2-(sb)}2] 1, 2 and [Cu{h2-(sb)}2] 3, 4, [where sbH = Schiff base, {salicylidene-2-aminophenol (saphh) for 1, 3 and salicylidene-3-nitro-1-aminobenzene (snabH) for 2, 4 have been synthesized by the interactions of anhydrous CuCl2 with sodium salt of corresponding Schiff bases in different molar ratio(s) using THF and benzene as reaction medium. The complexes 1, 2 have been further treated with various sodium salts of phenol, hydroxobenzaldehyde and aluminiumtetraisopropoxide to produce some novel mixed ligand complexes of the types, [(m-OAr)2Cu2{h2-(sb)}2] 5, 6, [(h2-OBa) Cu{h2-(sb)}] 7, 8 and [(m-OPri)2Al(OPri)2}Cu{h2-(sb)}] 9, 10. All these derivatives have been characterised by elemental analysis, spectral (IR, UV-visible and ESR), magnetic susceptibility measurements and fab-mass studies. On the basis of these results, a dimeric square planar geometry around copper(II) for the complexes 1, 2, 5 and 6 has been suggested.

IPC Code: Int.Cl.7 C07F1/08

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1165-1170

 

Solid acids in liquid phase esterification

N Nagaraju* & S Z Mohamed Shamshuddin

Received 29 June 2004; revised 29 March 2005

Catalytic activity of different protonated zeolites such as HY, Hβ, HZSM5 and sulfated oxides such as SO42-/Al2O3, SO42-/SiO2­, SO42-/ZrO2 in the esterification of propionic acid with various alcohols (C1-C5) over solid acids as catalysts has been investigated. The catalysts have been characterized for their total surface acidity, BET surface area and sulfur content in sulfated catalysts. Catalytic activity studies have been conducted in liquid phase under refluxing conditions. A systematic study has been made to find out the effects of nature of alcohols, amount of the catalyst and the duration of reaction in the synthesis of propionate esters. Product analysis has been done quantitatively by gas chromatography and qualitatively by GC-MS. All the catalysts have been found to be active towards the formation of propionate esters as the major reaction product. A good correlation between the concentration of acid sites and the catalytic activity of the catalysts has been observed.

IPC Code: Int. Cl7. C07C67/00, B01J20/16

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1171-1175

 

Theoretical estimation of heat capacity, density and thermal expansivity
of liquid metal alloys

J D Pandey*, N K Soni, R K Mishra, K K Tiwari & D K Dwivedia

Received 18 February 2005; revised 16 March 2005

Theoretical formulation has been made for estimating heat capacity, density and thermal expansivity of liquid metal alloys of Na+Cs and K+Rb at three different temperatures and at various compositions. The entire formulation has been based on Florys statistical theory. Theoretically estimated values have been compared with the observed values from literature, and good agreement has been found.

 

Indian Journal of Chemistry

Vol. 43A, June 2005, pp. 1176-1182

 

Electrosynthesis, photoelectrochemical and corrosion studies on (CdIn) Se, (CdGa) Se thin films

R K Pathak* & Sandhya Sankwa

Received 31 December 2003; revised 16 March 2005

Electrosynthesis of indium and gallium containing CdSe thin films on titanium substrate by electrochemical co-deposition method has been studied using aquous electrolytic bath at room temperature. The stoichiometry of electrodeposited films could be varied using different concentrations of indium and gallium in the electroplating solution. Photoelectrochemical properties of the electrosynthesised films have been reported. Charge carrier densities and flat-band potentials of the film electrodes have been determined from the capacitance measurements. Current-voltage behaviour of the electrodeposited films has been studied for the estimation of corrosion characteristics in the I2/I3 redox solution. Possibility of containment of corrosion using inhibitor has also been explored. The incorporation of indium and gallium during deposition of CdSe thin films enhances photoactivity and reduces corrosion rate. EDAX and SEM analyses have been used for compositional and surface characterisation of the films.

IPC Code: Int. Cl.7C23F13/00

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1183-1185

 

Acoustical study of substituted azoles in N,N-dimethylformamide at different temperatures

 

Deepali P Gulwade*, M L Narwade & S A Wadhal

Received 19 October 2004; revised 22 March 2005

Ultrasonic velocity and density measurements of 2-(5-amino-[1,3,4]thiadiazol-2-yl)-phenol) (L1), 2-(5-mercapto-[1,3,4] oxadiazol-2-yl)-phenol) (L2), 2-(5-mercapto-[1,3,4]thiadiazol-2-yl)-phenol) (L3), 2-[1-(H-benzimidazol-2-yl]-5-phenyl-1H-pyrazol-3-yl]-4-methyl phenol (L4) and 3-(2-hydroxy-5-methyl-phenyl-pyrazol-1-yl]-pyridin-4-yl-methanone (L5) in N,N-dimethylformamide (DMF) have been carried out at 303, 308, 313, 318 and 323 K in the solute concentration of 110-2 moldm-3. The experimental data have been used to calculate various acoustical parameters such as apparent molal volume (fv), apparent molal compressibility (fk(s)), intermolecular free length (Lf), specific acoustic impedance (Zs) and relative association (RA). The results suggest the presence of molecular interactions. The effect of temperature variation on the strength of molecular interactions has been studied and the data have been quantitatively explained in terms of solute-solute and solute-solvent interactions.

IPC Code: Int.Cl.7 B01J19/10

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1186-1190

Studies on optical and electrical properties of synthesized polycrystalline CdMoO4 and PbMoO4

P K Pandey*, N S Bhave & R B Kharat

Received 16 November 2004; revised 5 April 2005

Molybdates of Cd(II) and Pb(II) were synthesized by chemical route. The formation of CdMoO4 and PbMoO4 was confirmed by chemical analysis and powder X-ray diffraction (XRD) studies. Single-phase nature and purity of the molybdates was ascertained by matching their XRD data with the JCPDS data file. The powdered form of these molybdates was transformed into pellets under desired pressure using polyvinyl alcohol (PVA) as a binder. The polycrystalline pellets of these materials were then sintered at 900C for 30 h. These molybdates in polycrystalline pellet form were characterized with respect to diffused reflectance studies, D.C. electrical conductivity and thermoelectric power measurements. The optical band gap values for CdMoO4 and PbMoO4 were calculated from their reflectance measurements and found to be 2.14 eV and 2.94 eV, respectively. The D.C. electrical conductivity for the pellets of these molybdates was studied over the temperature range 300-600 K. Plot of log(σ) vs. (1/T) showed the semiconducting nature of these materials and clearly indicate a break corresponding to temperatures 408 K and 465 K, respectively, for CdMoO4 and PbMoO4. The activation energies below and above this break temperature have been estimated as 1.84 eV and 4.00 eV for CdMoO4 and 2.46 eV and 8.63 eV for PbMoO4.

IPC Code: Int. Cl.7 C01G11/00, C01G21/00

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1191-1196

 

Kinetics and mechanism of the interaction of N donor ligands with iodomethyl(aquo)cobaloxime

N Navaneetha & S Satyanarayana*

Received 9 February 2005; revised 8 April 2005

The equilibrium constants, rate constants and activation parameters for axial ligation of alkyl(aquo)cobaloximes by N donor ligands in the presence of 0.2 M buffer (to maintain pH) and 1.0 M KCl (to maintain ionic strength) have been determined spectrophotometrically at 442 nm. The rates and activation parameters (DH and DS) for the reactions have been estimated from the effect of concentration of ligand and temperature on the kinetics of these reactions. From the results of experimentally determined rates and activation parameters of cobaloximes, it can be concluded that the reactivity of metal complexes is greatly influenced by the ligand field effect of the co-ordinated groups and the presence of pi acceptor ligand, which provides a low energy pathway for electron transfer from a pi donor ligand anion leading to rate enhancement. The small negative DS and low DH values suggest the operation of a dissociative interchange (Id) substitution mechanism at the Co(III) center.

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1197-1202

 

Enrichment of indium from aqueous solution using functionalized sorbent

 

Saima Q Memon*, Najma Memon, M I Bhanger &  M Y Khuhawar

Received 10 August 2004; revised 29 March 2005

The present method utilizes styrene-divinylbenzene-based polymeric material containing phthalic acid as chelating agent to concentrate ultra trace amounts of indium ions in aqueous solutions. Sorption behaviour of In(III) ions under static and dynamic conditions onto the new synthetic resin is reported here. Maximum sorption has been achieved from solution with 8 min of agitation time in the pH range 5-8. The lowest concentration for quantitative recovery is 5 ppb with the preconcentration factor 666. The kinetics and thermodynamics of sorption have been studied in detail. The kinetics follows the first order rate equation with the rate constant k, equal to 0.645 0.05 min-1. The variation of equilibrium constant kc with temperature between 10C to 50C yields values of DH 33.71.96 kJmol-1, DS 136.96.4 Jmol-1K-1 and DG303K 7690 200 Jmol-1K-1. The sorption data in the concentration range 5.2610-6 to 2.1910-4 M L-1 In(III) ions follow Langmuir, Freundlich, and Dubinin-Radushkevich isotherms at all the temperatures investigated. The sorption of In(III) ions onto the synthesized resin in the presence of common anions and cations has also been measured.

IPC Code: Int.Cl.7 C22B58/00

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1203-1205

 

Ultrasonic studies of substituted isoxazoles and pyrazolines in dioxane and dioxane-water mixtures at different temperatures

 

Shashikant A Ikhe* & M L Narwade

Received 7 December 2004; revised 10 March 2005

Ultrasonic velocities and densities of 3-(2-hydroxy-3-bromo-5-methylphenyl)-5-phenyl isoxazole (L1), 1-phenyl-3-(2-hydroxy-3-bromo-5-methylphenyl)-5-(4-methoxyphenyl) pyrazoline (L2), in dioxane and different percentages of dioxane-water mixtures at different temperatures (303, 308, 313, 318, 323 K 0.1 K) have been evaluated at 0.01 M concentration. Different acoustic properties like partial molal volume (fv), adiabatic compressibility (bS), apparent molal compressibility (fk(s)), intermolecular free length (Lf), relative association (RA) and specific acoustic impedance (Z) have been determined by using single crystal interferometer at 1 MHz frequency. The obtained results have been interpreted in terms of solute solvent interactions.

IPC Code: Int.Cl.7 B01J19/10

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1206-1210

 

Chelation ion-exchange properties of 2,2-dihydroxybiphenyl-urea-formaldehyde (2:1:3) resin

 

Manjusha M Jadhao, L J Paliwal & NS Bhave

Received 19 January 2004; revised 3 March 2005

The resin 2,2-dihydroxybiphenyl-urea-formaldehyde [BPhUF], has been synthesized by the condensation of 2,2-dihydroxybiphenyl [BPh] and urea [U] with formaldehyde [F] in 2:1:3 molar ratio in presence of 2M HCl as a catalyst. UV-Vis, IR and NMR spectral studies have been carried out to elucidate the structure of resin. Ion exchange properties of this resin have been studied by batch equilibrium method for Fe3+, Cu2+, Ni2+, Co2+, Zn2+, Cd2+ and Pb2+ ions over the pH range, 1.5 to 6.5 and in media of various ionic strengths. In presence of chloride and nitrate ions, the uptake of Fe3+, Cu2+ and Ni2+ ions increases with increasing concentration of electrolyte while for Co2+, Zn2+, Cd2+ and Pb2+ ions, it decreases with increasing concentration of chloride, nitrate and sulphate ions. The resin shows a higher selectivity for Fe3+ ion over any other ion. Study of distribution ratio as a function of pH indicates that the amount of metal
ion taken up by resin increases with the increasing pH of the medium.

IPC Code: Int.Cl.7 B01J39/04

 

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1211-1214

 

Determination of cadmium(II), copper(II) and zinc(II) in water samples by flame atomic absorption spectrometry after cloud point extraction

 

Farzaneh Shemirani*, Shiva Dehghan Abkenar & Mohammad Reza Jamali

Received 20 May 2003; revised 28 February 2005

A preconcentration method for determination of low concentrations of Cd(II), Cu(II), and Zn(II) in water, using cloud point extraction is proposed. The analytes in the initial aqueous solution have been complexed with 8-hydroxyquinoline, with 0.06% (w/v) Triton X-114 added as surfactant. The complexation allows the separation of the analytes from other elements, which are not complexed. After phase separation, based on the cloud point of the mixture and dilution of the surfactant-rich phase with acidified methanolic solution, the enriched analytes have been determined by flame atomic absorption spectrometry. After optimization of complexation and extraction conditions, good enrichment factors have been obtained. The detection limits are 0.15 ng ml-1 for Cd(II), 0.72 ng ml-1 for Cu(II) and 0.03 ng ml-1 for Zn(II) in the initial solution. The relative standard deviations are lower than 3.1%. The method has been applied for analysis of the studied ions in tap water and river water samples. The method has been validated by the analysis of standard reference material.

Indian Journal of Chemistry

Vol. 44A, June 2005, pp. 1215-1218

 

Catalytic kinetic spectrophotometric determination of palladium(II) and its application to the determination of traces of propylthiouracil

A Jabbari, M Barzegar* & M Mohammadi

Received 19 September 2003; revised 3 March 2005

The catalytic-kinetic method has been proposed for the determination of palladium(II) based on its catalytic effect on the reaction of crystal violet with hypophosphite. The reaction has been monitored spectrophotometrically at 590 nm over the range 0.071-2.850 ppm of Pd(II). The influence of reaction variables and the effect of interfering ions have been studied. The limit of detection and relative standard deviation are 0.071 ppm and 2.76%, respectively. The developed method has been applied to the determination of Pd(II) in river water and Pd-C catalyst. The proposed method has also been applied for the determination of propylthiouracil in pharmaceutical samples based on its inhibitory effect on the palladium(II)catalyzed reaction between crystal violet and hypophosphite ions. The decrease in absorbance of crystal violet at 590 nm is proportional to 1.7-248.0 ppb of PTU. The limit of detection and RSD are 1.7 ppb and 2.53%, respectively.

IPC Code: Int. Cl.7 C07F15/00