Indian Journal of Chemistry

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

 

VOLUME 42A

NUMBER 3

MARCH 2003

 

CONTENTS

Papers

 

Theoretical study of the variation of first hyperpolarizability in a number of push-pull benzene, thiophene and trans butadiene molecules

K Mandal, T Chattopadhyay, P K Nandi* & S P Bhattacharyya

449

Studies of the dispersion state of CuO on TiO2 and CeO2-TiO2 and activity for NO+CO reaction

Y X Chen*, L P Lou, X Y Jiang, R X Zhou & X M Zheng 

460

Enthalpy of mixing of 1:1 electrolytic solutions at varying ionic strength at 298.15 K in water + 1,4-dioxane mixed solvent system

B R Deshwal & K C Singh* 

467

Kinetics of substitution of aqua ligands from cis-diaqua(cis-1,2-diaminocyclo-hexane)-platinum(II) perchlorate by glutathione in aqueous medium

Ramanath Sinha, A K Choudhury & Gauri S De*

473

Stabilisation of two Cu(I)-amino N bonds in presence of imino N’s

Michael G B Drew, Shubhamoy Chowdhury, Goutam K Patra & Dipankar Datta*

478

 

Mixed ligand binuclear copper(I) complexes containing CuI2N8 chromophores. Observation of emissions from MLCT excited states involving two different ligands

Derek A Tocher, Michael G B Drew, Shubhamoy Chowdhury,  Pradipta Purkayastha & Dipankar Datta*

484

Synthesis, characterization, and spectroscopic properties of heterobimetallic isopropoxides of Co, Ni and Cu containing diethanolaminate moiety

Kanupriya Sharma, Malti Sharma, Anirudh Singh* & Ram C Mehrotra*

493

Synthesis and characterisation of polymer supported Schiff base metal chelates

K Sivadasan Chettiyar & K Sreekumar*

499

Notes

 

Thermal decomposition behaviour of zinc(II)bis(oxalato)cobaltate(II)pentahydrate

N Deb

506

Vapour phase decomposition of cyclohexanol over mixed metal oxide system.

Manish M Shinde & Manohar R Sawant* 

510

Photo-catalytic reduction of chromium in aqueous solution by Fe3+ doped TiO2nanoparticles

Sanjay R Thakare* & R N Jugele

513

Adsorption and absorption of hydrogen species on silver electrode in alkaline solution

M Jafarian*, M G Mahjani, O Azizi & F Gobal

516

Acoustic characteristics of sodium salt of N-chloro-p-toluene sulphonamide in aqueous and binary aqueous media at 303 K

J Ishwara Bhat* & N V Sabitha

520

Ultrasonic studies of Schiff's base and substituted-2-azetidinones in CC14-water, ethanol-water and acetone-water mixtures at 298.5+0.1 K

Mohd. Idrees Mohd. Siddique, Pratibha B Agrawal, A G Doshi, A W Raut* & M L Narwade

526

Kinetics of oxidation of iodide ion by trans-(cyclohexane-1,2-diamine N,N,N′,N′-tetra-acetato)manganate(III) in weakly acidic solution

Mahammad Ali*, Amitava Datta & Sumana Gangopadhyay

531

Metal-heterocyclic thione interactions-14. Synthesis and spectroscopic of ruthenium(II) complexes containing pyridine-2-thione and bis(tertiaryphosphines/phosphine sulphides)

Tarlok S Lobana* & Renu Verma

534

Synthesis and spectral properties of cobalt(III) complexes containing SCN dimethylglyoxime and heterocyclic N-donor ligands

S C Nayak , K K Sahoo & P K Das*

537

Synthesis and characterization of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 2-[2¢-hydroxy salicylidene 5¢-(4²-phenyl,2²-thiazolylazo)] benzoic acid and 2-[2¢-hydroxy salicylidene 5¢-(4²-phenyl, 2²-thiazolylazo)] phenol

P P Hankare* & S S Chavan

540

Synthesis and characterization of tetrachloroniobium(V)aryloxides and their lewis base adducts

Neeraj Sharma*, B Bose, Atul Kaistha, S S Bhatt & S C Chaudhry

545

Studies on stabilities of 6-(5¢-8¢-hydroxy- quinolinic)methylene- 1,4,8,11-tetraazacyclo tetradecane-5,7-dione, 5-substituted 1,10-phenanthroline-copper(II) with Cu2+ or Co2+ binuclear mixed-coordinated systems

Xiao-jun Zhao , Xun-cheng Su, En-cui Yang, Hua-kuan Lin*, Shou-rong Zhu, Hong-wei Sun & Yun-ti Chen

551

Synthesis, structural characterization and thermal behaviour of bis(1-phenyl-1,3-butane-dionato) non-oxovanadium(IV) aryloxides

Neeraj Sharma*, Ritu, Atul Kaistha, Sarvjeet S Bhatt & Subhash C Chaudhry

555

Synthesis, characterization and ion exchange behaviour of a new phase of tin tungstate

Alpana H Parikh & Uma V Chudasama* 

559

Spectrophotometric determination of nickel in alloys using 5-mercapto-3-methyl-4-[2-pyridy-lideneamino]-1,2,4-triazole (MMPT)

Ronald A Nazareth & B Narayana* 

564

Fluorimetric method for the determination of trace amounts of mercury using 2-hydroxy-
1-naphthaldehydene-hydrazinecarbothio-amide

Chongqiu Jiang*& Fang He 

568

Faujasitic zeolite as sorbent for copper removal

S S Rayalu*, A Agrawal, M A Bawase & J U Ugwuanyi

573

Spectrophotometric determination of iron(III) in ore, pharmaceutical formulations, plant material and foodstuff using piroxicam

M B Melwanki, J Seetharamappa* & S P Masti

576

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 449-459

 

 

Theoretical study of the variation of first hyperpolarizability in a number of push-pull benzene, thiophene and trans butadiene molecules

K Mandal, T Chattopadhyay, P K Nandi * & S P Bhattacharyya

 

The static linear () and quadratic hyperpolarizabilities (vec) of a number of push-pull benzene, thiophene and trans 1,3-butadiene molecules have been calculated by using the AM1 finite field method. The calculated vec has been found to vary linearly with the static first hyperpolarizability (0) obtained using two state model. The calculated first hyperpolarizability (vec) shows satisfactory correlations with the ground state BLA parameter (r) of conduit, dipole moment, changes of conduit-donor / acceptor bond indices (IC-D/A) and the amount of charge transfer from donor / to acceptor (qD/Act) (with respect to mono substituted conduits), respectively. For each conduit vec varies linearly (quadratically) with qDct (qAct). Among the chosen molecules the most regular trend of  can be found with the molecular hardness parameter (). It has been observed that push-pull thiophene and trans 1,3-butadiene molecules exhibit rather close similarity with regard to the ground state polarization and the pattern of variation of the first hyperpolarizability with r and qD/Act.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 460-466

 

 

Studies of the dispersion state of CuO on TiO2 and CeO2-TiO2 and activity for NO+CO reaction

Y X Chen, L P Lou, X Y Jiang, R X Zhou & X M Zheng

 

The activities of CuO supported on TiO2 and ceria-modified TiO2 in catalyzing the NO reduction by CO have been examined with a microreactor-GC NO+CO reaction system, and the catalysts characterized by physical adsorption, TPR, XRD and NO-TPD. The CuO/TiO2 and CuO/CeO2-TiO2 catalysts increase the NO reduction by CO, probably due to the surface dispersed CuO and fine CuO crystallites. Pore structure data show that the pore size distribution of TiO2 is mainly as micro-pores and meso-pores, and the adsorption-desorption isotherm is the type IV of BDDT classification. TPR profiles indicate that Cu-Ti has four TPR peaks, α peak from highly dispersed CuO species, β peak from oxide clusters with a structure similar to CuO, γ peak from CuO crystallites and δ peak from the interaction of CuO and TiO2, TiO2 surface oxygen reduction. In addition, the phase change of TiO2 dosen’t show negative influence in catalytic activities. Among the tested catalysts, the catalyst with 12% CuO loading has the highest activity for NO+CO reaction, but at CuO loading of 3%, a crystallite of CuO has already been formed, which means that besides highly dispersed CuO, the CuO crystallite also plays an important role in NO+CO reaction, and the catalytic activities have a close relation with the CuO crystallite size and its micro structure data. NO-TPD profile also shows that the catalytic activities are closely related to NO dissociation - a rate-determining step for the NO+CO reaction, but are not affected by the amount of adsorbed NO.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 467-472

 

 

Enthalpy of mixing of 1:1 electrolytic solutions at varying ionic strength at 298.15 K in water + 1,4-dioxane mixed solvent system

B R Deshwal & K C Singh*

 

Enthalpy of mixing for six possible combinations of solutions of NaCl, KCl, NaBr and KBr have been determined as a function of ionic strength. The experiments have been performed at constant ionic strengths of 1.0 and 2.0 mol kg1 at 298.15 K using LKB flow microcalorimeter in water +1,4-dioxane mixed solvent system. Data differ appreciably from corresponding data in water and even do not support Young’s Cross Square Rule. Pitzer ion-interaction model is utilized to obtain binary and triplet interaction parameters i.e. and The data suggest that deviation from Young Cross Square Rule may arise from preferential solvation of the ions and ion clusters, as organic cosolvent is also incorporated in the solvation shell.

 

 

 

Indian Journal of Chemistry 

Vol. 42A, March 2003, pp. 473-477

 

 

Kinetics of substitution of aqua ligands from cis-diaqua(cis-1,2-diaminocyclohexane)platinum(II) perchlorate by glutathione in aqueous medium

Ramanath Sinha, A K Choudhury & Gauri S De*

 

The kinetics of the interaction of glutathione (reduced) (GSH) with [Pt(DACH)(H2O)2]2+ (DACH = cis-1,2-diaminocyclohexane) have been studied spectrophotometrically as a function of [Pt(DACH)(H2O)22+], [glutathione] and temperature at a particular pH (4.0). The reaction has been found to proceed via rapid outersphere association complex formation followed by two slow consecutive steps.The first step involves the transformation of the outersphere complex into the innersphere complex containing Pt-S bond and one aqua ligand while the second step involves chelation when the second aqua ligand is displaced. The association equlibrium constant (KE) and the two rate constants k1 and k2 have been evaluated. Activation parameters for both the steps have been calculated using Eyring equation (H1 = 32.87  1.31 kJ mol-1 , S1 = 187.24  4.2 JK-1 mol-1 , H2 = 30.50  0.09 kJ mol-1 , S2 = 223.05  0.28 JK-1 mol-1). The low enthalpy of activation and large negative values of entropy of activation indicate an associative mode of activation for both steps.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 478-483

 

 

Stabilisation of two Cu(I)-amino N bonds in presence of imino N’s

Michael G B Drew, Shubhamoy Chowdhury, Goutam K. Patra & Dipankar Datta*

 

Two structurally characterised examples of air stable CuI(amino N)2(imino N)2 chromophores having a Cu(II/I) potential of 0.01-0.19 V vs SCE in CH2Cl2 are provided using two tetradentate N-donor ligands.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 484-492

 

Mixed ligand binuclear copper(I) complexes containing CuI2N8 chromophores. Observation of emissions from MLCT excited states involving two different ligands

Derek A Tocher, Michael G B Drew, Shubhamoy Chowdhury, Pradipta Purkayastha & Dipankar Datta*

 

Using the 1:2 condensate (L) of diethylenetriamine and benzaldehyde as the main ligand, binuclear copper(I) complexes [Cu2L2(4,4-bipyridine)](ClO4)2.0.5H2O (1a) and [Cu2L2(1,2-bis(4-pyridyl)ethane)](ClO4)2 (1b) are synthesised. The two metal ions in 1a are bridged by 4,4-bipyridine and those in 1b by 1,2-bis(4-pyridyl)ethane. From the X-ray crystal structure of 1a, each metal ion is found to be bound to three N atoms of L and one of the two N atoms of the bridging ligand in a distorted tetrahedral fashion. The Cu(I)-N bond lengths in 1a lie in the range of 1.998(5)-2.229(6) Å. Electrochemical studies in dichloromethane (DCM) show that the CuI2N8 moieties in 1a and 1b are composed of two essentially non-interacting CuIN4 cores with CuII/I potential of 0.44 V vs. SCE. While 1a displays metal induced quenching of the inherent emission of 4,4-bipyridine in DCM solution, 1b exhibits two weak emission bands in DCM solution at 425 and 477 nm (total quantum yield = 3.59 x 10-5) originating from MLCT excited states. With the help of Extended Hückel calculations it is established that the higher energy emission in 1b is from Cu(I)  bridging-ligand charge transfer excited state and the lower energy one in 1b from Cu(I)  L charge transfer excited state.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 493-498

 

 

Synthesis, characterization, and spectroscopic properties of heterobimetallic isopropoxides of Co, Ni and Cu containing diethanolaminate moiety

Kanupriya Sharma, Malti Sharma, Anirudh Singh* & Ram C. Mehrotra*

 

Hydrocarbon-insoluble derivatives of the type M(deaH)2 (M = Co, Ni, Cu(II); deaH2 = diethanolamine) on reactions with Al(OPri)3 in 1:2 molar ratio yield hydrocarbon-soluble, monomeric heterobimetallic derivatives [{Al(OPri)2}2M(dea)2]. A different type of soluble heteroleptic derivatives has been prepared by the reactions of M{Al(OPri)4}2 with deaH2 in 1:1, 1:2 and 1:3 molar ratios. The reaction of M{Al(OPri)4}2 with four equivalents of diethanolamine yields a benzene insoluble product of composition M{Al(dea)2}2. All these new derivatives have been characterized by elemental analyses, molecular weight measurements and spectroscopic (Electronic and IR) studies.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 499-505

 

 

Synthesis and characterisation of polymer supported
Schiff base metal chelates

K Sivadasan Chettiyar & K Sreekumar*

 

Divinyl benzene (DVB)-crosslinked polystyrene has been functionalised to introduce thiosemicarbazone ligand function. This Schiff base thiosemicarbazone ligand is used to prepare chelates of Fe(III), Co(II), Ni(II), Cu(II) and Zn(II). The factors influencing metal complexation like temperature, pH, influence of solvent etc are examined. The polymeric metal complexes are well characterised by spectral techniques and assigned a proper geometry on the basis of analytical, magnetic measurement and spectral data.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 506-509

 

 

Thermal decomposition behaviour of zinc(II)bis(oxalato)cobaltate(II)pentahydrate

N Deb

 

Zinc(II)bis(oxalato)cobaltate(II)pentahydrate, Zn[Co(C2O4)2]5H2O, has been synthesized and characterized by elemental analysis, IR spectral, reflectance and X-ray powder diffraction studies. Thermal decomposition studies (TG, DTG and DTA) in air show that at ca.1000oC, generation of a mixture of ZnO and CoO is attributed through the formation of zinc cobalt oxide, ZnCo2O4 at 420oC. DSC study in nitrogen upto 600oC show the endothermic decomposition and a mixture of zinc oxide and cobalt oxide is formed at the end.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 510-512

 

 

Vapour phase decomposition of cyclohexanol
over mixed metal oxide system.

Manish M Shinde & Manohar R Sawant*

 

Mixed metal oxides viz. ferrites have been investigated for their catalytic activity for vapour phase decomposition of cyclohexanol. A good correlation between electronic activation energy and catalytic activity has been observed. The ferrites have been prepared by co-precipitation technique and characterized by XRD, IR and electrical conductivity measurements. The kinetics of the reaction has been studied. The reaction follows typical first order kinetics. The activation energy for cyclohexanol decomposition has been found to be 29.45 kJ/mol.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 513-515

 

 

Photo-catalytic reduction of chromium in aqueous solution by
Fe3+ doped TiO2 nanoparticles

Sanjay R Thakare* & R N Jugele

 

The present study deals with the photo-catalytic reduction of Cr (VI) by TiO2 nanoparticles. A detailed adsorption study of Cr (VI) by Fe3+ doped TiO2 at different pH shows that the adsorption of chromium by TiO2 nanoparticles is governed by charge of TiO2 nanoparticles, which depends on the pH of solution. Kinetic studies show that reduction and adsorption of Cr (VI) by Fe3+doped TiO2 are not similar. Photocatalytic reduction of Cr (VI) by Fe3+ doped TiO2 is more feasible at low pH. Fe3+doped TiO2 nanoparticles accelerate the reduction rate of Cr (VI) to Cr (III) than commercially available TiO2 particles.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 516-519

 

 

Adsorption and absorption of hydrogen species on silver electrode
in alkaline solution

M Jafarian, M G Mahjani , O Azizi & F Gobal

 

The processes of adsorption and absorption of H atoms on silver electrode in alkaline media has been studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The potential range in the CV studies has been between -0.1 and -1.6 V /Ag-AgCl. In the first cycle, two cathodic and three anodic peaks have been observed. The H atom electrosorption current peak at ca. -0.6 V / Ag-AgCl, which appears at second cycle, is assigned to hydrogen absorption states. Nyquist plots consist of two overlapping semi-circles of variable diameters depending on the extent of the cathodic dc-potential offset. Hydrogen absorption occurs simultaneously with the hydrogen evolution reaction and competes with it. The H atoms are converted to H2 rather than being sorbed into the polycrystalline Ag when the potential is more negative. These H atoms in the bulk of Ag electrode can be removed only by heating the electrode on flame.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 520-525

 

 

Acoustic characteristics of sodium salt of N-chloro-p-toluene sulphonamide in aqueous and binary aqueous media at 303 K.

J Ishwara Bhat* & N V Sabitha

 

Acoustic investigation of the sodium salt of N-chloro-p-toluene sulphonamide in water + propan –2-ol, water +propan-1-ol and water +dioxan (upto 80% v/v) has been carried out at 303 K. Various parameters such as adiabatic compressibility, intermolecular free length, specific acoustic impedance, relative association, apparent molar adiabatic compressibility, and solvation number have been computed . Ultrasonic velocity has increased with increase in concentration of N-chloro-p-toluene sulphonamide for a given composition. Adiabatic compressibility and inter molecular free length increase from one composition to another. All these observations have been made use of in establishing the nature of ion-solvent interaction present under existing conditions.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 526-530

 

 

Ultrasonic studies of Schiff's base and substituted-2-azetidinones in CC14-water, ethanol-water and acetone-water mixtures at 298.5+0.1 K

Mohd. Idrees Mohd. Siddique, Pratibha B Agrawal, A G Doshi, A W Raut* & M L Narwade

 

Ultrasonic velocity and density measurements on 2-thienylidine-4'-methyl aniline, 2- thienylidine-4'-nitroaniline and N-(4'-methyl phenyl)-4-(2"- thienyl)-2-azetidinones in 70% as well as in different percentages(v/v) of CC14-water, ethanol-water and acetone-water mixtures have been carried out at 298.5+0.1 K. Various thermodynamic data such as apparent molal volume, apparent molal compressibility, specific acoustic impedance and relative associaiton have been computed and these parameters have been interpreted in terms of solute-solvent and solute-solute interactions.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 531-533

 

 

Kinetics of oxidation of iodide ion by
trans-(cyclohexane-1,2-diamine N,N,N′,N′-tetraacetato) manganate(III) in weakly acidic solution

Mahammad Ali*, Amitava Datta & Sumana Gangopadhyay

 

Kinetics of redox reaction between I- and [MnIII(cdta)]- has been investigated in aqueous solution by a stopped–flow technique at pH 3.26 (acetate buffer) and at 30, 35 40 and 45 oC. The overall reaction is third order  first order in [MnIII(cdta)-] and second order in [I-]. Though no direct evidence has been obtained, an inner-sphere mechanism has been proposed based on the lability of the complex and is supported by the large negative value of S# (-168  6) JK-1 mol-1.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 534-536

 

Metal-heterocyclic thione interactions-14. Synthesis and spectroscopic of ruthenium(II) complexes containing pyridine-2-thione and bis(tertiaryphosphines/phosphine sulphides)

Tarlok S Lobana* & Renu Verma

 

A series of ruthenium(II) complexes containing pyridine-2-thione (C5H5NS) and bis(tertiary phosphine/ phosphine chalcogenide) are described. The complexes of stoichiometry, Ru(C5H4NS)2(L-L) {where L-L = Ph2P-CH=CH-PPh2 (dppen-PP) (1) Ph2P-CH2-P(S)Ph2 (dppm-PS) (2), Ph2P-CH2-CH2-P(S)Ph2 (dppe-PS) (3) and Ph2P(S)-CH2-CH2-P(S)Ph2 (dppe-SS (dppe-SS) (4)) are formed by the replacement of PPh3 from Ru(C5H4NS)2(PPh3)2 using a bis(tertiary phosphine) ligand in the presence of Et3N base in dry toluene under dry nitrogen. All these compounds have been characterised by analytical data, IR and NMR (lH and 13C) spectroscopy. Octahedral structures are suggested for the complexes in which diphosphines and pyridine-2-thiolate are chelating.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 537-539

 

 

Synthesis and spectral properties of cobalt(III) complexes containing SCN dimethylglyoxime and heterocyclic N-donor ligands

S C Nayak , K K Sahoo, P K Das*

 

Different nitrogen donor ligands (pyridine, piperidine, quinoline, iso-quinoline, triazole, indole, benzimidazole, benzotriazole, carbazole) react with Co(SCN)2 and dimethylglyoxime (DH2) in ethanolic medium in presence of air to form a number of new Co(III) complexes of the type trans- [Co(DH)2(L)(SCN)], which are characterised on the basis of electronic and IR spectra NMR, (1H and 13C) spectra, thermogravimetric (TG-DT) analysis and conductance measurements. The thiocyanate group is S-bonded. The NMR observation suggests that in solution, these compounds exist as mixtures of neutral species [Co(DH)2(L)(SCN)] and the salt [Co(DH)2(SCN)2]. TG and DT analysis show that these complexes proceed through polymeric intermediate, and give Co3O4 as the end product.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 540-544

 

Synthesis and characterization of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 2-[2-hydroxy salicylidene 5-(4-phenyl,2-thiazolylazo)]benzoic acid and 2-[2-hydroxy salicylidene 5-(4-phenyl, 2-thiazolylazo)] phenol

P P Hankare* & S S Chavan

 

Metal complexes of the type [M(L).2H2O]2 [L=2-[2-hydroxy salicylidene 5-(4-phenyl 2-thiazolylazo)]benzoic acid (L1) and 2-[2-hydroxysalicylidene 5-(4-phenyl 2-thiazolylazo)] phenol (L2)]; M= Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized and characterized by elemental analysis, magnetic susceptibility, molar conductance, TGA, X-ray diffraction and spectral studies. L1 and L2 acts as dibasic tetradentate ligands and the complexes appear to be octahedral. Antibacterial activities of ligands and their metal complexes have been determined against Escherichia coli, Bacillus substilis, Klebsiella Pneumoniae, Pseudomonas aerogens, Salmonella paratyphi B, Staphylococcus aureus and Proteus vulgaris.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 545-550

 

 

Synthesis and characterization of tetrachloroniobium(V)aryloxides and their lewis base adducts

Neeraj Sharma*, B Bose, Atul Kaistha, S S Bhatt &  S C Chaudhry

 

Tetrachloroniobium(V) aryloxides of composition [NbCl4(OAr1,2)]2 (OAr1 = OC6H4But-4 and OAr2=OC6H4OMe-4) have been synthesized by the reaction of NbCl5 with 4-t-butyl and 4-methoxyphenols in CCl4. The characterization of the complexes has been accomplished by elemental analyses, conductivity measurements, molecular weight determinations, IR, 1H NMR, UV-VIS and MS techniques. Thermal behaviour of the complexes has also been studied by TGA-DTA techniques. From non-isothermal TG data, the kinetic and thermodynamic parameters have been calculated using Coats-Redfern equation and the most probable mechanism for thermal decomposition of these complexes is ascertained. The reactions of complexes with a variety of nitrogenous and oxygenous bases have yielded 1:1 adducts authenticated by usual physicochemical and IR spectral studies.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 551-558

 

 

Studies on stabilities of 6-(5-8-hydroxyquinolinic)
methylene- 1,4,8,11-tetraazacyclo tetradecane-5,7-dione,
5-substituted 1,10-phenanthroline-copper(II) with Cu2+ or Co2+ binuclear mixed-coordinated systems

Xiao-jun Zhao , Xun-cheng Su, En-cui Yang, Hua-kuan Lin*, Shou-rong Zhu, Hong-wei Sun & Yun-ti Chen

 

C-functionalized dioxotetraamine 6-(5-8-hydroxyquinolinic)methylene-1,4,8,11-tetraazacyclo tetradecane-5,7-dione ligand, containing two independent chelating groups, L has been synthesized and characterized by elemental analysis, IR, mass spectra and 1H NMR spectra. The pH titration has been performed to study the stabilities of L-5-R-1,10-phenanthroline-Cu(II) with proton, copper(II) and cobalt(II). The results show that for Cu2+ and Co2+, 8-hydroxyquinoline is a stronger chelating reagent than dioxotetraamine macrocycles. Using molecular mechanics (MM+) calculation, the stability of ternary mixed system on Co(II)-L-5-substituted-1,10-phenanthroline-Cu() and Cu(II)-L-5-substituted-1,10 -phenanthroline Cu(II), compared with the coordination ability for different coordination sites and for different metal ions [Co(II) and Cu(II)] at same coordination site have been studied.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 555-558

 

 

Synthesis, structural characterization and thermal behaviour of bis
(1-phenyl-1,3-butanedionato) non-oxovanadium(IV) aryloxides

Neeraj Sharma*, Ritu, Atul Kaistha, Sarvjeet S Bhatt & Subhash C Chaudhry

 

The non-oxo vanadium(IV) aryloxides of composition [VCl(bzac)2(OAr)1,2] {where OAr1= -OC6H4But-4 and OAr2= -OC6H4OMe-4; bzac= 1-phenyl-1,3-butane-dionato ion (C6H5COCHCOCH3)-} have been synthesized by the direct reaction of VCl2(bzac)2 with 4-tert-butyl and 4-methoxy phenols in CCl4 while [V(bzac)2(OAr)21,2] have been prepared from VCl2(bzac)2 and trimethylsilyl derivatives of these phenols. The complexes have been characterized by elemental analyses, molar conductance, molecular mass determinations, FT- infrared, UV-vis, ESR spectroscopy and magnetic susceptibility measurements. Thermal behaviour of the complexes is consistent with the proposed formulations.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 559-563

 

 

Synthesis, characterization and ion exchange behaviour of a new phase of tin tungstate

Alpana H Parikh & Uma V Chudasama*

 

A new phase of tin tungstate, an inorganic ion exchanger of the class of tetravalent metal acid (tma) salt has been synthesized with good ion exchange properties. The material has been characterized for elemental analysis, thermal analysis (TGA, DSC), FTIR spectroscopy, X-ray analysis and surface area measurements (BET method). Ion exchange capacity has been determined and effect of heating on ion exchange capacity studied. The distribution behaviour towards several metal ions in different electrolyte media/concentrations has also been studied. The utility of this material has been demonstrated by carrying out some binary metal ion separations. Further, as a case study, the separation/recovery of lead from an effluent containing lead has been demonstrated.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 564-567

 

Spectrophotometric determination of nickel in alloys using 5-mercapto-3-methyl-4-[2-pyridylideneamino]-1,2,4-triazole (MMPT)

Ronald A Nazareth & B Narayana*

 

A simple and rapid spectrophotometric method for the determination of nickel has been developed using 5-mercapto-3-methyl-4-[2-pyridylideneamino]-1,2,4-triazole (MMPT). The green coloured 1:2 complex formed shows the absorption maximum at 400 nm. The method is free from interference from many of the associated metal ions. It obeys the Beer’s law in the range of 3 ppm to 11.5 ppm of Ni(II) with molar absorptivity and sandell sensitivity of 8.51103dm3/mol/cm-1 and 0.03 µg/cm2 respectively. Analyses of various alloys have been carried out with satisfactory and reproducible results.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 568-572

 

Fluorimetric method for the determination of
trace amounts of mercury using
2-hydroxy-1-naphthaldehydene-hydrazinecarbothio-amide

Chongqiu Jiang*& Fang He

 

A fluorescent reagent, 2-hydroxy-1-naphthaldehydene-hydrazinecarbothioamide (HNHTA) has been synthesized and the fluorescent quenching reaction of this reagent with mercury is studied. Based on this chelation, a highly sensitive spectrofluorimetric method has been developed for the determination of trace amounts of mercury. The interference of other mental ions has also been studied. This method has been successfully applied to the determination of mercury in waste water and prawn.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 573-575

 

 

Faujasitic zeolite as sorbent for copper removal

S S Rayalu*, A Agrawal, M A Bawase & J U Ugwuanyi

 

Detailed studies have been conducted for removal of copper ions from its aqueous solution by flyash based faujasitic zeolites. Studies conducted on FAZ-Y and Cu systems reveal that low adsorbate concentration; neutral pH and higher temperatures favour the sorption of Cu ions. Almost 100% removal of the Cu ions has been achieved at a dose of 7 g/l for 500 mgl-1 for a contact time of 4 h at neutral pH using FAZ-Y. The equilibrium data fits well in the Freundlich and Langmuir adsorption model. Effect of temperature is explained on the basis of the solubility and chemical potential of the adsorbate. The rate of sorption is observed to increase with increase in temperature.

 

 

 

Indian Journal of Chemistry

Vol. 42A, March 2003, pp. 576-578

 

 

Spectrophotometric determination of iron(III) in ore, pharmaceutical formulations, plant material and foodstuff using piroxicam

M B Melwanki, J Seetharamappa* & S P Masti

 

Piroxicam (PR) has been proposed as a sensitive and selective reagent for the spectrophotometric determination of Fe(III) in ore, pharmaceutical formulations, plant material and foodstuff. The method is based on the formation of a chloroform-soluble red coloured 1:1 complex by the reaction of Fe(III) with PR in Walpole buffer. Beer’s law is valid over the concentration range of 0.46.4 ppm. The coloured complex exhibits an absorption maximum at 510 nm with molar absorptivity of 1.82104 l mol-1 cm-1 and Sandell’s sensitivity of 17.32 ng cm-2. The absorbances are found to increase linearly with increase in concentration of iron, which are corroborated by the calculated correlation coefficient value (0.9992). The effects of foreign ions in the determination of Fe(III) have been studied. Statistical comparison of the results with those of direct AAS method shows good agreement and indicates no significant difference in precision.