Indian Journal of Chemistry

 

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

 

VOLUME 40A NUMBER 4 APRIL 2001

 

CONTENTS

 

Papers

 

1,5- and 1,7-naphthalenediols in the excited singlet state: A study by electronic spectra

N Rajendiran, N Radha & M Swaminathan*

 

331

Solvatochromic parameters and linear solvation energy relationships for hydrolysis of hydroxamic acids

Kallol K Ghosh * Pankaj Tamrakar & Santosh Singh Thakur

 

340

A thermodynamic study of complex formation between dibenzo -18-crown-6 and dicyclohexano-18-crown-6 with La3+, Hg2+, Tl+ and Pb2+ in some binary mixed non-aqueous solvents using conductometric method

Gholamhossein Rounaghi*, Malihe Samadi Kazemi & Mohammad Hassan Soorgi

 

345

Micellar Effect on the reaction of chromium(VI) oxidation of formaldehyde in the presence and absence of picolinic acid in aqueous media : A kinetic study

S K Mondal, M Das, D Kar & A K Das*

 

352

Equilibrium studies on mixed-ligand mixed-metal complexes of copper(II), nickel(II) and zinc(II) with glycylvaline and imidazole

R N Patel*, R P Shrivastava, Nripendra Singh, Subodh Kumar & Krishna B. Pandeya

 

361

Synthesis and characterisation of platinum(II) complexes of 1-methyl-2-{(arylazo)imidazoles} and their dioxolene derivatives

Goutam Kumar Rauth, Sanjib Pal, ebasis Das & Chittaranjan Sinha*

368

Characterization and investigation of polycyclic aromatic compounds present in petrol, diesel, kerosene and 2T oil using excitation emission matrix fluorescence

Digambara Patra, Lakshmi Sireesha K. & K Mishra*

374

Notes

 

Molecular adducts of some phenylmercury(II) O,O'-alkylene dithiophosphates

S.K. Srivastava*, S.B. Saxena & S. Jain

 

380

 

Molar volume and apparent molar volume of copper(ii) soap+Methanol + benzene system at various temperatures

V P Mehta, P R Talesara & Rashmi Sharma*

 

383

 

Adsorption of dyes on rice husk ash

Sumanjit* & N Prasad

 

388

 

Carbon formation during volatile organic compound oxidation over a nickel catalyst

G D L P Jayathilaka, C Hettige, R R Mahanama & D P Dissanayake*

 

392

 

Dye-surfactant interaction near CMC: Phenazinium dyes sodium dodecylsulphate

P M Saikia , R K Dutta* & S N Bhat

 

396

 

Micellar characteristics of the copper (II) soap + methanol + benzene system at various temperatures

V P Mehta, P R Talesara & Rashmi Sharma*

 

399

 

Redox catalytic property of small mercury particle

Nikhil R. Jana & Tarasankar Pal*

 

403

 

Synthesis of dimethyl ether on supported Cu-Mn catalysts

Zhao-Yin Hou*, Jin-Hua Fei, Gong-Xin Qi & Xiao-Ming Zheng

 

406

 

Kinetics and mechanism of oxidation of chromium(III)-L-glutamic acid complex by periodate

Hassan A Ewais, Eman S H Khaled & Ahmed A Abdel-khalek*

410

 

Synthesis of the binuclear copper(I) complex containing bis(diphenylphosphino)ethane

Wang Dongmei, Yang Ruina*, Liu Yingfan & Jin Douman

 

415

 

Synthesis and characterization of monooxo-vanadium(V)aryloxides

Neeraj Sharma, Anoop K Sood, S S Bhatt & S C Chaudhry

 

419

 

Synthesis and characterization of manganese(IV) and manganese(II) complexes with bis(2-hydroxy-1-naphthaldehydehyde)- malonoyldihydrazone.

R. A Lal*, A Kumar & J Chakraborty

 

422

 

Synthesis, spectral and electrochemical studies of ruthenium(II)/(III) complexes of alicyclic b-ketamines

N Prasanna, S Srinivasan, G Rajagopal &P R Athappan*

 

426

 

Pre-concentration and determination of trace elements in natural waters by inductively coupled plasma-atomic emission spectrometry

A Ramesh, K Rama Mohan , K Seshaiah* &J Rajasekhar

 

430

 

Spectrophotometric determination of cadmium (ii) with 5-(2 - carbomethoxy phenyl) azo-8-quinolinol in presence of sodium dodecylsulphate as surfactant

R. Saran* & N.K. Baishya

 

433

 

Authors for correspondence are indicated by (*)

 

 

 

 


Indian Journal of Chemistry
Vol. 40A April 2001, pp. 331-339

 

 

Solvatochromism and proton transfer kinetics of 1,5- and 1,7-naphthalenediols in the excited singlet state: A study by electronic spectra

 

N Rajendiran, N Radha & M Swaminathan*

Department of Chemistry, Annamalai University, Annamalainagar 608 002, India

 

Received 28 January 2000; revised 2 January 2001

 

A study of solvent and pH effects on absorption and fluorescence of 1,7- and 1,5- naphthalenediols has been carried out. The life-times of neutral and monoanionic forms of both naphthalenediols have been determined. Solvatochromic shifts of 1,7-Naphthalenediol (1,7ND) is different from 1,5-naphthalenediol (1,5ND) both in ground and excited states. The difference is more in S1 state. In 1,5ND the -OH groups are a a ' and placed symmetrically, but in 1,7ND the -OH groups are a, b ' and their positions are not symmetrical. The large solvatochromic and Stoke's shifts are explained by the point group symmetry of naphthalenediols. The stretched sigmoidal fluorimetric titration curves obtained for the equilibrium between neutral form and monoanion of both NDs are analysed using Weller's Steady state kinetics and lifetimes of the species. These curves meet only at the ground state pKa values. The excited state equilibrium constants determined from rate constants and by other methods are compared.

 

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 340-344

 

Solvatochromic parameters and linear solvation energy relationships for hydrolysis of hydroxamic acids

 

Kallol K Ghosh * Pankaj Tamrakar & Santosh Singh Thakur

School of Studies in Chemistry,

Pt. Ravishankar Shukla University, Raipur, 492010

 

Received 17 April 2000; revised 6 November 2000

 

Kinetic solvent effects on hydrolysis of hydroxamic acids of the type R.N (OH). C = O.R/ [ R = H ; R/ = CH3 , C6H5 , C6H4 - OH; R=CH3 - C6H4 R/ = C6H5 ] in aqueous mixtures (1070% v/v) of some polar protic, polar aprotic and low polarity basic solvents have been studied. The  solvatochromic parameters a for the hydrogen-bond-donating ability, b, for the hydrogen-bond-accepting ability and, p*, for the dipolarity / polarizability and linear solvation energy relationships have been used to quantify solvent effects. Kamlet and Taft's triparametric equation explain the greater than 70% of the effect of solvent on the hydrolysis. The other parameters i.e., D, ET and Z have also been used.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 345-351

 

A thermodynamic study of complex formation between dibenzo -18-crown-6 anddicyclohexano-18-crown-6 with La,Hg,Tl and Pb in some binary mixed non-aqueous solvents using conductometric method

 

Gholamhossein Rounaghi*, Malihe Samadi Kazemi & Mohammad Hassan Soorgi

Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran

 

Received 19 July 2000; revised 22 November 2000

 

The complextion reactions between La , Tland Pb ions with the macrocyclicligand , dibenzo - 18 - crown - 6 (DB18C6) and of Hg and Tlions with dicyclohexa - 18 - crown - 6 (DC18C6) have been studied in dimethylformamide (DMF) - acetonitrile(AN) and methanol (MeOH) - acetonitrile (AN) binary systems at different temperature susing conductometric method . The conductance data show that the stoichiometry of allof the complexes is 1:1 . The values of thermodynamic parameters( and ) for complexation reactions have been determined from temperature dependence of formation constants . The obtained results show that the stability of complexes and thethermodynamic parameters ( , ) are sensitive to the nature and composition of the mixed solvents. The stability constants of all complexes (except for DB18C6 - Pb) increase with increasing concentration of solvent with the lower donocity ( based on Gutmann doncity scale ) in binary mixed systems. The selectivity order of DB18C6 for metal cations in different concentrations of AN in dimetylformamide-acetonitrile binary systems is : Tl>La> Pb. In addition , the obtained results show that the stability of DC18C6 - Tl complex at most temperatures is higher than that of DB18C6 - Tlcomplex which reflects the effect of substituents on the polyether ring .

 

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 352-360

 

Micellar Effect on the reaction of chromium(VI) oxidation of formaldehyde in the presence and absence of picolinic acid in aqueous media : A kinetic study

S.K. Mondal, M. Das, D. Kar & A.K. Das*

Department of Chemistry, Visva-Bharati University, Santiniketan 731 23, India

Received 29 August 2000; revised 9 January 2001

 

The kinetics and mechanism of Cr(VI) oxidation of formaldehyde in the presence and absence of picolinic acid (PA) in aqueous acid media have been carried out under the conditions, [formaldehyde]T >> [Cr(VI)]T at different temperatures. Under the kinetic conditions, the monomeric species of Cr(VI) has been found kinetically active in the absence of PA while in the PA catalysed path, Cr(VI)-PA complex has been suggested as the active oxidant. In the In the PA catalysed path, Cr(VI)-PA complex receives a nucleophilic attack by the substrate to form a ternary complex which subsequently experiences a redox decomposition (through 2e transfer) leading to formic acid and Cr(IV)-PA complex. Then Cr(IV)-PA complex participates further in the oxidation of formaldehyde and ultimately is converted into Cr(III)-PA complex. In the uncatalysed path, Cr(VI)-substrate ester experiences an acid catalysed redox decomposition (2e transfer) at the rate determining step. The uncatalysed path shows a second-order dependence on [H+] while the PA catalysed path shows a zeroth order dependence on [H+]. Both the uncatalysed and PA catalysed paths show first-order dependence on [formaldehyde]T and [Cr(VI)]T. The PA catalysed path is first order in [PA]T. All these observations (i.e. dependence patterns on the reactants) remain unaltered in the presence of externally added surfactants. Effect of cationic surfactant (i.e. cetylpyridinium chloride, CPC) and anionic surfactant (i.e. sodium dodecyl sulfate, SDS) has been studied both in the presence and absence of PA. CPC inhibits the reactions while SDS catalyses the reactions. The observed micellar effects have been explained by considering the partitioning of the reactants between the micellar and aqueous phase. Applicability of different kinetic models, e.g. pseudo-phase ion exchange (PIE) model, Menger-Portnoy model, Piszkiewicz cooperative model, has been tested to explain the observed micellar effects.

 

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 361-367

 

Equilibrium studies on mixed-ligand mixed-metal complexes of copper(II), nickel(II)
and zinc(II) with glycylvaline and imidazole

 

R N Patel*, R P Shrivastava, Nripendra Singh & Subodh Kumar

Department of Chemistry, A.P.S. University, Rewa (M.P.) 486003, India

and

Krishna B. Pandeya

Vice- chancellor, C.S.J.M. University, Kanpur 208024, India

 

Received 8 August 2000; revised 11 October 2000

 

Imidazolato bridged homo/hetero binuclear complexes of copper(II) nickel(II) and zinc(II) formed with glycylvalinate have been studied by pH-metry, EPR and visible absorption spectrometry in aqueous medium at 25 1o and I = 0.1 M NaClO4. The experimental data have been obtained for the following species (A- = glycylvalinate and B = imidazole) :M2+, AH2+, AH, A-, BH+, B, M(OH)+, M(OH)2, M(A)+, M(A)(OH), M(B)2+,M(A)(B)+, M2(A)2B2+, M2(A)2(B-H)+, M1M2(A)(B)2+ and M1M2(A)2(B-H)+. The anion (B-H)- provides (N1-, N3) bridging bidentate co-ordination in M2(A)2(B-H)+ and M1M2(A)2(B-H)+ complexes.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 368-373

 

Synthesis and characterisation of platinum(II) complexes of 1-methyl-2
-{(arylazo)imidazoles} and their dioxolene derivatives

 

Goutam Kumar Rauth, Sanjib Pal, Debasis Das & Chittaranjan Sinha*

Department of Chemistry, The University of Burdwan, Burdwan, 713104, India.

 

1-Methyl-2-(arylazo)imidazoles, p-R-C6H4-N=N-C3H2 N2-1-CH3, (RaaiMe (1); R = H(a), Me(b), Cl(c) have been treated with K2PtCl4 to synthesise brown-red Pt(RaaiMe)Cl2 (2) complexes. Addition of dioxolene in the presence of Et3N to CHCl3-MeOH solution of Pt(RaaiMe)Cl2 yield green coloured mixed complexes of the composition [Pt(RaaiMe)(O,O)] (O,O = catecholate (cat) (3); 4-tert-butylcatecholate (tbcat), (4); 3,5-di-tert-butylcatecholate (dtbcat), (5); tetracholorocatecholate (tccat), (6) ). The complexes have been characterised by elemental analyses, IR, UV-Vis-NIR and 1H NMR spectral data. The solution electronic spectra exhibit ligand-to-ligand charge transfer (LLCT) transition at red to NIR region; the position and symmetry of the band depend on the substituent type on the dioxolene and arylazoimidazole frames. This is qualitatively assigned as HOMO(dioxolene) LUMO(RaaiMe). Cyclic voltammogram shows consecutive oxidation of catechols to semiquinone and semiquinone to quinone and azo reductions. The difference in first oxidation and reduction potential is linearly related with LLCT transition energy. The comparison of the physical properties of present series of complexes with palladium(II)-analogues show the involvement of Pt(II)-dp orbitals to stabilise the complexes.

 

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 374-379

 

Characterization and investigation of polycyclic aromatic compounds present
in petrol, diesel, kerosene and 2T oil using excitation emission matrix fluorescence

Digambara Patra, Lakshmi Sireesha K. & A K Mishra*

Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India

 

Received 5 April 2000; revised 7 August 2000

 

Excitation emission matrix fluorescence fingerprint has been used for characterization of motor oils like diesel, petrol, kerosene and lubricant oil (2T oil). Heavy oil like diesel and 2T oil contain mostly higher membered polycyclic aromatic compounds, whereas lighter oils like petrol and kerosene contain intermediate polycyclic aromatic compounds along with their lower membered aromatics. Analysis of synthetic mixture of diesel and kerosene has been carried out to check contamination of diesel qualitatively by kerosene. A multivariate method to estimate kerosene and diesel in their mixture comprising their dilute solutions has been used, which gives a satisfactory result. Estimation of 2T oil (0-10 %, v/v) in petrol has been successfully carried out using this technique.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 380-382

 

Molecular adducts of some phenylmercury(II)O,O'-alkylene
dithiophosphates

 

S.K. Srivastava*, S.B. Saxena & S. Jain

School of Studies in Chemistry, Jiwaji University, Gwalior 474 011 (M.P.), India

 

The interactions of phenylmercury O,O'-alkylene dithiophosphates, [C6H5HgS(S)POGO] (G = -CH2C(H)-CH3 and -C(CH3)2(CH3)2C-) with various O- and S- donor Lewis bases have yielded new molecular adducts. The elemental analyses and spectral (IR and 1H NMR) data suggest the presence of three - coordinated mercury atom.

 

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 383-387

 

Molar volume and apparent molar volume of copper(II) soap+
Methanol + benzene system at various temperatures
.

 

V P Mehta, P R Talesara & Rashmi Sharma*;

Deptt. of Chemistry S.D.Govt. College, Beawar 305 901 India

 

Received 19 July 2000; revised 11 December 2000

 

Studies on density of copper(II) soaps in mixture of benzene + methanol at various temperatures (40,45,50,55C) have been made. The cmc values in higher volume percent of methanol are higher than those in higher volume percent of benzene. With regard to chain length of soaps cmc values follow the order C6>C8. Masson equation has been applied successfully to interpret apparent molar volume of copper soaps in benzene + methanol. The studies of temperature effect on various interactions suggest that interactions between soap-solvent molecules increase with the rise in temperature when non-polar hydrocarbon is predominant in the solvent mixture whereas soap-soap interactions increase with the rise in temperature when methanol is predominant at below and above cmc.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 388-391

 

Adsorption of dyes on rice husk ash

Sumanjit* & N. Prasad

Department of Pharmaceutical Science, Guru Nanak Dev University, Amritsar 143 005. India

 

Received 10 august 1998, revised 14 November 2000

 

Rice husk ash (RHA), a waste from rice mills has been used as an adsorbent for the removal of chemical oxygen demand (COD) from aqueous solutions of textile dyes. The adsorption capacity of RHA for five aqueous acid dye solutions has been determined by adsorption isotherm. The adsorption data have been fitted to Freundlich isotherm and Langmuir isotherm by the least square method and the values of the constants k, n, Cm and b have been obtained. The effect of contact time, pH, adsorbent concentrations and rate constants for each dye have been calculated.

 

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 392-395

 

Carbon formation during volatile organic compound oxidation
over a nickel catalyst

 

G D L P Jayathilaka, C Hettige, K R R Mahanama & D P Dissanayake*

Department of Chemistry, University of Colombo, Colombo 3, Sri Lanka

 

Effect of metal additives on carbon formation during volatile organic compound oxidation over Ni/Al2O3 catalysts has been investigated. Cyclohexane is used as the model volatile organic compound. Reaction is carried out under oxygen limited conditions with just sufficient oxygen to convert ~10% of cyclohexane into carbon dioxide and water. Presence of Ca, Ba, Sr or Zn (10% by weight) in oxide form in the Ni/Al2O3 catalyst (25% Ni by weight) does not improve the resistance to carbon formation. In contrast, a remarkable improvement in the resistance to carbon formation was observed when Mg (10% by weight) is present. To understand the effect of Mg, nickel catalysts have been synthesized over MgO and CaO supports. It is seen that the catalyst Ni/MgO was highly resistant to carbon formation. X-ray diffraction studies show that the NiO phase is highly stable over the MgO support but reduces to metallic nickel over the CaO support.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 396-398

 

Dye-surfactant interaction near CMC:
Phenazinium dyes sodium dodecylsulphate

 

P M Saikia & R K Dutta*

Department of Chemical Sciences, Tezpur University, Tezpur-784 028, Assam, India

E-mail: robind@agnigarh.tezu.ernet.in

 

and

 

S N Bhat

North Eastern Hill University, Shillong-793 027, Meghalaya, India

 

Received 24 February 2000; revised 27 September 2000

 

The interactions between phenazinium dyes and sodium dodecylsulphate, with concentrations of the surfactant near critical micelle concentration (CMC) in the sub-micellar concentration range, have been studied. It has been suggested that the spectral bands, which were hitherto attributed to self-aggregation of the dye, may actually be due to change in microenvironment of the dye chromophore on incorporation of the dye into pre-micelles.

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 399-402

 

Micellar characteristics of the copper (II) soap + methanol + benzene system at various temperatures

V P Mehta, P R Talesara & Rashmi Sharma*

Department of Chemistry, S D Govt. College, Beawar 305 901 India

Received 20 December 1999; revised 23 may 2000

 

The viscosity of copper (II) soaps in nonaqueous solvents of varying composition has been determined at four different temperatures (40, 45, 50, 55o C). The viscosity of the system increases with increasing soap concentration at all temperatures and decreases with rise in temperature. With increase in the number of carbon atoms in the hydrophobic chain, viscosity and cmc of the soaps increase and decrease respectively. The effect of soap concentration on viscosity of soap solution has been discussed in terms of Einstein, Thomas, Vand, Moulik and Jones-Dole equations. These studies suggest that there is an increase in the interaction between solute-solute molecules and a decrease in the interaction between solute-solvent molecules. Various parameters derived from viscometric equations confirm that two types of micelles are formed and the behaviour of the soap changes at about 50% methanol concentration.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 403-405

 

Redox catalytic property of small mercury particle

 

Nikhil R. Jana & Tarasankar Pal*

Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India

Department of Chemistry, R.R.R Mahavidyala, Radhanagar, Hooghly 721 406

 

Small mercury particles have been synthesized in aqueous media and their redox catalytic property investigated using methylene blue as a redox probe.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 406-409

 

Synthesis of dimethyl ether on supported Cu-Mn catalysts

 

Zhao-Yin Hou*, Jin-Hua Fei, Gong-Xin Qi & Xiao-Ming Zheng

Institute of Catalysis, Zhejiang University(Xixi Campus), Hangzhou, 310028, P.R.China

 

A new catalyst system Cu-Mn-(M)Ox supported on g-Al2O3 has been developed for the synthesis of dimethyl ether (DME) directly from synthesis gas in a fixed-bed reactor, (M = Zn, Cr, W, Mo, Fe, Co or Ni). The results show that the conversion of CO and the selectivity of DME change greatly with n(Cu)/n(Mn) ratio, while Zn and Cr show little effect on the reaction, W and Mo decreases the conversion of CO, increases the selectivity of CO2 and CH4. On introducing Fe to the catalyst, the main products are CH3OH and CH4. The optimum DME yield of obtained is 46.0% (at 63.5% conversion of CO) at 2.0 MPa, 275oC, 1500h-1 on Cu2Mn4Zn1.0Ox/g-Al2O3 catalyst.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 410-414

 

Kinetics and mechanism of oxidation of chromium(III)-L-glutamic acid complex by periodate

 

Hassan A Ewais, Eman S H Khaled & Ahmed A Abdel-khalek*

Chemistry Department, Faculty of Science at Beni-Suef, Cairo University, Beni-Suef City, Egypt

 

Received 13 April 2000; revised 12 December 2000

 

The kinetics of oxidation of the chromium(III)-L-glutamic acid complex, [CrIII(L)2(H2O)2]+, by periodate in aqueous solutions has been found to obey the following equation.:

d [CrVI] / dt = k2 K5 [CrIII]T [IVII]T / {1 + ( [H+] / K1 ) + K5 [IVII]T}

where k2 is the rate constant for the electron transfer process, K1 the equilibrium constant for dissociation of [CrIII(L)2(H2O)2+] to [CrIII(L)2(H2O)(OH)] + H+, and K5 the pre-equilibrium formation constant. Values of k2 = 2.93 10-3 s-1, K1 = 6.26 10-4 mol dm-3 and K5 = 88.41 dm3 mol-1 have been obtained at 30 oC and I = 0.2 mol dm-3. Thermodynamic activation parameters have been calculated. It is proposed that electron transfer proceeds through an inner-sphere mechanism via coordination of IO4- to chromium(III).

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 415-418

Synthesis of the binuclear copper(I) complex containing bis(diphenylphosphino)ethane

 

Wang Dongmei, Yang Ruina*, Liu Yingfan

Henan Institute of Chemistry, Zhengzhou 450002, P R China

 

and

 

Jin Douman

State Key Lab of Coordination Chemistry, Nanjing University 210093, P R China

 

Received 18 July 2000; revised 22 september 2000

 

At room temperature, the reaction of metallic copper powder with 2-thenoyltrifluoroacetone and bis(diphenylphosphino)ethane gives the binuclear copper(I) complex, [Cu(dppe)(tfac)]2. The complex has been characterized by physico-chemical and spectroscopic methods. X-Ray structure of the title complex shows that 2-thenoyltrifluoroacetone behaves as chelating ligand and dppe coordinates as bridging bidentate ligand to CuI atoms in the newly prepared copperI complex. The crystal is monoclinic, space group C2/c, with cell parameters a= 25.215(6); b= 15.304(9), c= 18.851(6) ,β= 107.20(3), Z= 4, V= 6949.0(2) 3, R=0.06682, Rw=0.07326.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 419-421

 

Synthesis and characterization of monooxovanadium(V)aryloxides.

 

Neeraj Sharma, Anoop K Sood, S S Bhatt & S C Chaudhry

Department of Chemistry, Himachal Pradesh University, SummerHill , Shimla 171005, India.

 

The monooxovanadium(V)aryloxides of composition VOCl3-n(OAr1,2)n (where n=1 to 3 ; OAr1 = - OC6H2But2-2,6-Me-4 and OAr2 = - OC6H4NO2-4) have been synthesized by the reaction of VOCl3 with 2,6-di-t.-butyl-4-methylphenol and trimethylsilyl derivative of 4-nitrophenol respectively in CCl4. The aryloxides have been characterized by IR,1NMR,UV-vis spectral and elemental analysis.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 422-425

 

Synthesis and characterization of manganese(IV) and manganese(II) complexes with
bis(2-hydroxy-1-naphthaldehydehyde)- malonoyldihydrazone
.

 

R A Lal*, A Kumar & J Chakraborty

Department of Chemistry, Tripura University, Agartala 799 004, Tripura, India.

 

Received 13 December 1999; revised 19 September 2000

 

The manganese complexes [MnIV(CH2L)(H2O)2](1) and [MnII (CH2LH2)(A)2] (where A = H2O (2), pyridine (py, 3), 3-picoline (3-pic,4) and 4-picoline (4-pic, 5)) have been synthesized from bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (CH2LH4) and characterized by elemental analyses, molecular weight and molar conductance data, magnetic moment, electronic, IR and ESR spectral data.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 426-429

 

Synthesis, spectral and electrochemical studies of ruthenium(II)/(III) complexes
of alicyclic
b-ketamines

 

N Prasanna, S Srinivasan, G rajagopal & P R Athappan*

Department of Inorganic Chemistry, Madurai Kamaraj University, Madurai 625 021

 

Received 1 September 1999; revised 9 January 2001

 

A series of ruthenium(II)/(III) complexes of alicyclic b-ketamines derived from 2-formylcyclohexanone and 4-X-substituted anilines, HFCA-X (where H is an ionisable enolic hydrogen and X=H, Cl, Br, OMe and NO2), have been prepared and characterized by spectroscopic techniques. The IR spectral data suggest the coordination of enolic oxygen and imino nitrogen to ruthenium. Ruthenium(II) complexes are diamagnetic (low spin d6, S=0 and in solutions show intense MLCT transition. The redox behaviours have been studied by cyclic voltammetry. The solid state low temperature ESR spectra of Ru(III) complexes show a low spin symmetry.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 430-432

 

Pre-concentration and determination of trace elements in natural waters
by inductively coupled plasma-atomic emission spectrometry

 

A Ramesh, K Rama Mohan & K Seshaiah*

Department of Chemistry, Sri Venkateswara University, Tirupati 517 502, India

 

and

 

J Rajasekhar

Research & Development, Amara Raja Batteries Limited, Karakambadi, Tirupati 517 520, India

 

Received 1 May 2000; revised 25 October 2000

 

A method has been developed for the determination of Cd (II), Cu (II), Mn (II), Ni (II), Pb (II) and Zn (II) in natural waters by inductively coupled plasma-atomic emission spectrometry after pre-concentration by solvent extraction with piperidine dithiocarbamate (pipDTC). The metals are complexed with pipDTC and the complexes extracted into isobutyl methyl ketone and subsequently back-extracted into nitric acid. Metals in nitric acid have been determined by aspirating into argon plasma of ICP-AES. The method has been applied for the determination of the tested metal ions in natural waters.

 

 

Indian Journal of Chemistry
Vol. 40A April 2001, pp. 433-436

Spectrophotometric determination of cadmium (ii) with 5-(2 - carbomethoxyphenyl)
azo-8-quinolinol in presence of sodium dodecylsulphate as surfactant

 

R. Saran*

Chemical Laboratory, Atomic Minerals Division, Department of Atomic Energy
Assam Rifles (P.O.), Shillong 793 011. India

 

and

 

N.K. Baishya

Department. Of Chemistry, Gauhati Univeristy, Gopinath Bardoloi Nagar, Guwahati 781 014, India.

 

Received 29 May 2000, revised 18 October 2000

 

The reaction between cadmium (II) and 5-(2-carbomethoxyphenyl) azo-8-quinolinol in aqueous medium at pH 4.0-4.8 results in an insoluble complex. Addition of sodium dodecylsulfate gives a vermillion red coloured solution which is stable for at least 8 hours. Beers law is obeyed in the range 0.04 - 0.88 ppm of cadmium (II) at 503 nm. The molar absorptivity and Sandells sensitivity at 503 nm are 1.05 x 105 1 mol -1 cm -1 and 1.0 ng cm-2, respectively. Alkali metals, alkaline earths, manganese (II) and chromium (VI) do not interfere. The interference of Cu(II), Pb(II), Ni(II), Fe(III), Co(II) and Mo(VI) is removed by extracting their complexes formed with the reagent at pH 5.5 - 6.5 in to methyl isobutyl ketone. However, Zn(II) and Hg(II) interfere. The method has been applied for the determination of cadmium (II) in borewell, tap and river and nallah (with suspected discharge of industrial waste) water samples. The results agree closely with the values obtained by atomic absorption spectrophotometry.

 

 

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