Indian Journal of Chemistry

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

 

VOLUME 46A

NUMBER 10

October 2007

 

CONTENTS

 

 

1565

 

Prediction of new organo-noble gas compounds by ab initio quantum chemical calculations

 

 

 

 

 

 

Astha Sethi & B M Deb*

 

 

 

 

Three new linear organo-noble gas molecules, HArCCH, HKrCCKrH and HKrCCXeH, incorporating one or two noble gas atoms into the acetylene framework, is predicted by ab initio quantum chemical calculations. The bonding in HArCCH is different from that in the other molecules. For molecules containing two noble gas atoms, a 90° dihedral mode involving the atoms and the HCCH internuclear axis, is the preferred stereochemical approach. However, a noble gas atom could not be inserted into the biphenyl molecule as well as between two benzene molecules.

 

1573

 

Synthesis, structure and properties of a monomeric copper(II) complex with a multidentate pyridylpyrazole ligand

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Vibha Mishra, Shubha Singh &
Rabindranath Mukherjee*

 

 

 

 

A new monomeric Cu(II) complex is reported which reveals hitherto unknown coordination mode of the pyridylpyrazole ligand. X-ray data reveal trigonal bipyramidal geometry around Cu(II), which is retained in solution. Crystal packing diagram of this complex reveals a rare class of bifurcated C-Hp interactions. Notably, pp  interactions lead to the formation of 2D network structure.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1579

 

Bromide mediated oxidation of antimony(III) by cerium(IV) in aqueous sulphuric acid medium

 

 

 

 

 

 

 

 

 

 

D S Munavalli, K A Thabaj, S A Chimatadar & S T Nandibewoor*

 

 

 

 

Micro quantities (10-3 mol dm-3) of bromide mediated oxidation of Sb(III) by Ce(IV) in aqueous sulphuric acid has been studied at 25°C and I = 3.10 mol dm-3.

 

 

1585

 

Synthesis and physicochemical studies of a new molybdenum(IV)pterin complex undergoing reaction with trimethylamine N-oxide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Baidyanath Ghosh & Parag S Roy*

 

 

 

 

A new compound, [MoIVL2].3CH3OH, has been synthesized using a redox reaction between Na2MoO4.2H2O and 2-pivaloylamino-6-phenacyl-isoxanthopterin. The optimized bond length and bond angle data tally with the literature X-ray structural data. The kinetic and stoichiometric aspects of its reaction with Me3N→O have been studied. The negative ∆S# value (– 282.8J K-1 mol-1) is consistent with an associative mechanism for this process. The product of this reaction, a μ-oxo binuclear Mo(V) complex, indicates oxygen atom transfer nature of this reaction.1H-NMR, fluorescence spectra and CV data indicate the redox “non-innocent” behavior of the pterin ligand.

 

 

1594

 

Synthesis, characterization and 3D molecular modeling of some ternary complexes of Cu(II), Ni(II), Co(II), Zn(II), Sm(III), Th(IV) and UO2(VI) with Schiff base derived from the sulfa drug sulfabenzamide and 1,10-phenanthroline

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R C Maurya*, J Chourasia & P Sharma

 

 

 

 

New mixed-ligand ternary complexes of cu(II), ni(II), co(II), zn(II), sm(III), th(IV) and uo2(VI) with 1,10-phenanthroline and the Schiff base derived from salicylaldehyde and the sulfa drug sulfabenzamide, have been synthesized.

 

 

Notes

 

 

1605

 

Estimation of cohesive force, energy of vaporization, heat of vaporization, cohesive energy density, solubility parameter and van der Waals constant of binary liquid mixtures using generalized hole theory

 

 

 

 

 

 

 

 

 

 

J D Pandey*, Tanu Srivastava, Prakash Chandra, Rajput Prashant & D K Dwivedi

 

 

 

 

Using the recently proposed generalized hole theory, the internal pressure, energy of vaporization, heat of vaporization, cohesive energy density, solubility parameter and van der Waals constant have been calculated for seven binary liquid mixtures, viz., cyclohexane + cyclohexanol, n-heptane + toluene,
n-heptane + n-hexane, cyclohexane + n-hexane, acetonitrile + benzene, benzene + dimethylformamide, and acetonitrile + dimethylformamide.

 

 

1611

 

Synthesis, structural characterization and antibacterial studies of some biosensitive mixed ligand copper(II) complexes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

N Raman* & J Dhaveethu Raja

 

 

 

 

A series of copper(II) complexes of mixed ligands with Schiff bases derived from 2-aminophenol/2-aminobenzoic acid with substituted benzaldehydes and 1,10-phenonthroline have been synthesized.

 

 

 

1615

 

Liquid-liquid extraction of ultra trace amounts of technetium produced by 100Mo (p, 2n) 99mTc nuclear reaction in cyclotron

 

 

 

 

 

 

 

 

Nasser Dallali, Manoochehr Ghanbari,
Yadollah Yamini, Behrooz Fateh & Y K Agrawal*

 

 

 

 

A simple, rapid and reliable method using cetyl trimethyl ammonium bromide salt is described for the selective extraction of ultra trace amounts of Tc produced by 100Mo (p, 2n) 99mTc nuclear reaction in cyclotron. The extraction of Tc is found to be quantitative after 5 min upon equilibration, from 0.1 mol L-1 HCl solution in presence of milligrams of various diverse ions. However, I- and Cr2O72- interfere in the extraction of Tc.

 

 

1618

 

Rapid analysis of americium and plutonium in environmental samples by alpha-spectrometry

 

 

 

 

 

 

 

 

 

 

H Salar Amoli* & J Barker

 

 

 

 

A new method by which a uniform and thin layer of the sample is formed on the alpha-spectrometer disc by electroplating is reported to assay americium and plutonium in soil samples. Prior to electrodeposition, the sample is separated by short column chromatography. Current of 900 mA and plating time of 90 min in the pH range 2–2.5 is found to be optimum for the deposition of americium. Optimum conditions for separation and electrodeposition of plutonium from soil samples have also been obtained. The modified procedure has been successfully applied for the simultaneous determination of Am and Pu.

 

 

1621

 

Spectrophotometric determination of hydrazine using bromine and methyl red

 

 

 

 

 

 

 

 

 

Mary George, K S Nagaraja* & N Balasubramanian

 

 

 

 

A known excess of bromine when treated with hydrazine is reduced to bromide and the unreacted bromine is determined using methyl red. The molar absorptivity is calculated to be
9.95 x104 L mol-1cm-1. Beer’s law is obeyed in the range 0-6 mg of hydrazine in an overall aqueous volume of 25 mL with a correlation coefficient of 0.999 and detection limit of 0.25 mg. The proposed method has been successfully applied for the estimation of hydrazine in boiler feed water samples.

 

 

1625

 

Spectrophotometric determination of nickel(II)
with 2-hydroxy-3-methoxy benzaldehyde thiosemi-carbazone

 

 

 

 

 

 

 

 

 

A Praveen Kumar, P Raveendra Reddy* &
V Krishna Reddy

 

 

 

 

2-Hydroxy-3-methoxy benzaldehyde thiosemicarbazone reacts with nickel(II) in aqueous solution at pH 4.0-8.0 and at room temperature to form a yellow coloured 1:1 complex with absorption maximum at 410 nm and molar absorptivity 2.05´104 l mol-1 cm-1. Beer’s law is obeyed in the range of 0.058-2.347 μg ml-1 of Ni(II). A method for the determination of Ni(II) by second order derivative spectrophotometry is also  proposed. The proposed methods have been successfully applied for determination of Ni(II) in aluminium-based steels, drinking water, plant samples and vegetable oil.

 

 

1630

 

Determination of pKa’s of hydroxamic acids by nucleophilic substitution reaction

 

 

 

 

 

 

 

 

Ashish  Shrivastava & Kallol K. Ghosh*

 

 

 

 

Acid dissociation constants of some para-substituted benzohydroxamic (4-XC6H4CONHOH) and N-methyl para-substituted benzohydroxamic acids [4-XC6H4CON(OH)CH3], where X = H, CH3, CH3O, NO2, Cl have been determined spectrophotometrically  by nucleophilic substitution reactions of
p-nitrophenyl acetate with hydroxamate ions at 27 ± 0.1 °C. All reactions follow pseudo-first order kinetics under the condition of excess nucleophile.

 

 

Authors for correspondence are indicated by (*)


 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1565-1572

 

Prediction of new organo-noble gas compounds by ab initio quantumchemical calculations

Astha Sethi & B M Deb*

Received 14 June 2007; revised 28 August 2007

The existence of three new, linear organo-noble gas molecules, HArCCH, HKrCCKrH and HKrCCXeH, incorporating one or two noble gas atoms into the acetylene framework, is predicted by ab initio quantum chemical calculations using different methods and basis sets. Their optimized bond lengths, stability, nature of bonding and the role of correlation energy, preferred dissociation channel as well as propensity to attack by electrophiles have been reported. The bonding in HArCCH is different from that in the other molecules. For molecules containing two noble gas atoms, a 90° dihedral mode involving the atoms and the HCCH internuclear axis, is the preferred stereochemical approach. However, a noble gas atom could not be inserted into the biphenyl molecule as well as between two benzene molecules.

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1573-1578

 

Synthesis, structure and properties of a monomeric copper(II) complex with a multidentate pyridylpyrazole ligand

Vibha Mishra, Shubha Singh & Rabindranath Mukherjee*

Received 30 May 2007; revised 14 August 2007

Using a potentially multidentate ligand, L6(2,6-bis[3-(2'-pyridyl)pyrazol-1-ylmethyl]pyridine), having five N donor sites, a new mononuclear copper(II) compound, [Cu(L6)][ClO4]2, has been synthesized. X-ray crystallographic analysis reveals that it is in the monoclinic space group C2/c with all five donor sites coordinating with copper(II) to provide a distorted trigonal bipyramidal coordination environment around copper. Closer inspection of crystal packing diagram reveals the formation of 2D network structure, assembled via two types of noncovalent interactions. Notably, p p interactions between p electron cloud of pyridine rings of pyridylpyrazole unit lead to the formation of a linear chain, which is then connected to another chain via C–H p interactions involving pyridyl C–H (4-position) of central pyridine ring of L6 and p electron cloud of pyridine ring of pyridylpyrazole unit in a bifurcated fashion. Coordination geometry in solution (MeCN) state has been assessed by absorption and EPR spectroscopy. Cyclic voltammetry reveals inherent flexibility of the ligand system to allow stabilization of copper(I) oxidation state.

IPC Code: Int. Cl.8 C07F1/08

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1579-1584

 

Bromide mediated oxidation of antimony(III) by cerium(IV) in aqueous sulphuric acid medium

D S Munavalli, K A Thabaj, S A Chimatadar & S T Nandibewoor*

Received 18 May 2007; revised 9 August 2007

The micro amount (10-3 mol dm-3) of bromide mediated oxidation of antimony(III) by cerium(IV) in an aqueous sulphuric acid medium has been studied spectrophotometrically at 25°C and I = 3.10 mol dm-3. In the presence of bromide, one mole of antimony(III) requires two moles of cerium(IV). The reaction is first order with respect to [cerium(IV)] and [bromide], whereas the order with respect to [antimony(III)] is less than unity. Increase in [sulphuric acid] accelerates the reaction rate. The order with respect to [H+ ion] is less than unity. Added products, cerium(III) and antimony(V) do not have any significant effect on the rate of reaction. The active species of oxidant is identified as H3Ce(SO4)4-, whereas that of reductant as SbBr2+. The possible reaction mechanism is proposed and the activation parameters determined and discussed.

IPC Code: Int. Cl.8 C07B33/00

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1585-1593

 

Synthesis and physicochemical studies of a new molybdenum (IV)-pterin complex undergoing reaction with trimethylamine N-oxide

Baidyanath Ghosh & Parag S Roy*

Received 27 September 2006; revised 17 August 2007

A new compound, [MoIVL2].3CH3OH (2), has been synthesized using a redox reaction between Na2MoO4.2H2O and 2-pivaloylamino-6-phenacyl-isoxanthopterin, and characterized by elemental analysis, electrospray ionization mass spectrometry, various spectroscopic methods and cyclic voltammetry. Its optimized geometry (with lowest steric energy) has been obtained by molecular mechanics method; the optimized bond lengths and bond angles data tally with the literature X-ray structural data. Both the kinetic and stoichiometric aspects of its reaction with Me3N→O have been studied. The negative ∆S# (J K-1 mol-1) value (-282.8) is consistent with an associative mechanism for this process. The product of this reaction has been isolated and characterized to be a μ-oxo binuclear Mo(V) complex, indicating oxygen atom transfer nature of this reaction.1H-NMR, fluorescence spectra and CV data indicate the redox “non-innocent” behavior of the pterin ligand in the present case.

IPC Code: Int. Cl.8 C07F11/00

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1594-1604

 

Synthesis, characterization and 3D molecular modeling of some ternary complexes of Cu(II), Ni(II), Co(II), Zn(II), Sm(III), Th(IV) and UO2(VI) with Schiff base derived from the sulfa drug sulfabenzamide and 1,10-phenanthroline

R C Maurya *, J Chourasia & P Sharma

Received 23 February 2006; rerevised 21 July 2007

Some new mixed-ligand ternary complexes of cu(II), ni(II), co(II), zn(II), sm(III), th(IV) and uo2(VI) with the Schiff base derived from salicylaldehyde and the sulfa drug sulfabenzamide, [N-(salicylidene)sulfabenzamide] (LH) and the heterocyclic base 1,10-phenanthroline (phen) have been synthesized and characterized by IR, NMR, diffuse reflectance spectra, and thermal, magnetic and molar conductance measurements. Thermal analyses indicate the presence of lattice and coordinated water molecules in the complexes, which is also supported by the IR spectral data. The coordination by the azomethine nitrogen is inferred by the upfield shifting of the –CH=N– signal in the NMR spectra and the shift of n(C=N) to lower wave numbers in the IR spectra upon complexation. The Schiff base ligand (LH) acts as a monobasic bidentate ligand in complex formation. The presence of anion, viz., CH3COO- or NO3-  in the coordination sphere is also inferred by the IR spectral data and conductance measurements. The general compositions of the complexes are found to be [M(L)(phen)(OAc)(H2O)], where M = Cu(II), Ni(II), Co(II), Zn(II) or UO2(VI), [Sm(L)(phen)(OAc)2(H2O)2]×H2O and [Th(L)(phen)(NO3)3(H2O)]×4H2O, where AcOH = acetic acid and LH = [N-(salicylidene)sulfabenzamide].

IPC Code: Int. C8 C07F1/08; C07F3/06; C07F5/00; C07F15/04; C07F15/06; C07F17/00; C07F251/02

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1605-1610

 

Estimation of cohesive force, energy of vaporization, heat of vaporization, cohesive energy density, solubility parameter and van der Waals constant of binary liquid mixtures using generalized hole theory

J D Pandey, Tanu Srivastava, Prakash Chandra, Rajput Prashant & D K Dwivedi

Received 16 April 2007; revised 30 August 2007

Using the recently proposed generalized hole theory, the internal pressure, energy of vaporization, heat of vaporization, cohesive energy density, solubility parameter and van der Waals constant have been calculated for seven binary liquid mixtures, namely cyclohexane + cyclohexanol, n-heptane + toluene, n-heptane + n-hexane, cyclohexane + n-hexane, acetonitrile + benzene, benzene + dimethylformamide, and acetonitrile + dimethylformamide. Satisfactory results have been obtained for the studied systems.

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1611-1614

 

Synthesis, structural characterization and antibacterial studies of some biosensitive mixed ligand copper(II) complexes

N Raman* &  J Dhaveethu Raja

Received 8 September 2006; revised 16 August 2007

A series of copper(II) complexes of mixed ligands with Schiff bases derived from 2-aminophenol/2-aminobenzoic acid with substituted benzaldehydes and 1,10-phenonthroline have been synthesized. Microanalytical, magnetic susceptibility, IR, UV-vis, CV, ESR and mass spectral techniques have been used to confirm the structure of these complexes. Their low electrical conductance values indicate that all the complexes are non-electrolytes. The monomeric nature of the complexes is evidenced from their magnetic susceptibility values. Electronic and EPR spectra of the complexes suggest that they have distorted octahedral geometry. The electrochemical behavior, the anodic and cathodic potential and the number of electron transfer have been calculated using cyclic voltammogram. The synthesized compounds have been tested against microorganisms such as Escherichia coli, Bacillus subtilis, Micrococcus luteus and Proteus vulgaris. A comparative study of the MIC values of the ligands and the complexes indicate that the complexes exhibit higher antibacterial activity than the free ligand and control.

IPC Code: Int. Cl.8 C07F1/08

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1615-1617

 

Liquid-liquid extraction of ultra trace amounts of technetium produced by 100Mo (p, 2n) 99mTc nuclear reaction in cyclotron

Nasser Dallali, Manoochehr Ghanbari, Yadollah Yamini, Behrooz Fateh & Y K Agrawal*

Received 22 June 2007; revised 21 August 2007

A simple, rapid and reliable method for the selective extraction of ultra trace amounts of Tc produced by 100Mo (p, 2n) 99mTc nuclear reaction in cyclotron, using cetyl trimethyl ammonium bromide salt, CTAB (a quaternary ammonium salt) is described here. Effect of various experimental parameters, viz., equilibration time, sample matrix, type of organic solvent and diverse ions on the extraction efficiency and selectivity has been investigated. The extraction of Tc has been found to be quantitative after 5 min, upon equilibration from 0.1 mol L-1 HCl solution in presence of milligrams of various diverse ions. However, I- and  interfere in the extraction of Tc. The extracted Tc has been stripped into aqueous phase in presence of HClO4 or sodium dodecyl sulphate and then analyzed for 99mTc by g-ray spectrometry. The 99m Tc has been measured by ICP-MS in the range from 0.15–5.5 Bq L-1 with detection limit 0.03 m Bq ml-1.

IPC Code: Int. Cl.8 B01D11/00

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1618-1620

 

Rapid analysis of americium and plutonium in environmental samples by alpha-spectrometry

H Salar Amoli* & J Barker

Received 23 April 2007; revised 17 August 2007

A new method to assay americium and plutonium in soil samples is reported here. Using the method, it is possible to have a uniform and thin layer of the sample on alpha-spectrometer disc by electroplating. Prior to electrodeposition, the sample is separated by short column chromatography. A current of 900 mA and a plating time of 90 min in the pH range 2–2.5 have been found to be the best conditions for the deposition of americium. Optimum conditions for separation and electrodeposition of plutonium from soil samples have also been obtained. The modified procedures have been successfully applied for the simultaneous determination of Am and Pu.

IPC Code: Int.Cl.8 G01N21/00

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1621-1624

 

Spectrophotometric determination of hydrazine using bromine and methyl red

Mary George, K S, Nagaraja ,* & N Balasubramanian

Received 13 November 2006; revised 17 August 2007

Hydrazine has been determined by its oxidation to nitrogen with a known excess of bromine. Bromine in acidic medium bleaches the dye methyl red. A known excess of bromine when treated with hydrazine is reduced to bromide and the unreacted bromine is determined using methyl red. The molar absorptivity is calculated to be 9.95 x104 L mol-1cm-1. The method obeys Beer’s law in the range 0-6 mg of hydrazine in an overall aqueous volume of 25 mL with a correlation coefficient of 0.999.The detection limit is 0.25mg of sample. The relative standard deviation is 2.7% (n=10) at 3 mg of hydrazine. Interferences due to various foreign ions have been studied. The proposed method has been successfully applied for the estimation of hydrazine in boiler feed water samples. The results obtained in the developed method compare well with the p-dimethylaminobenzaldehyde (p-DAB) method and by the recovery studies of added hydrazine.

IPC Code: Int. Cl.8 G01N21/25

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1625-1629

 

Spectrophotometric determination of nickel(II) with 2-hydroxy-3-methoxy-benzaldehyde thiosemicarbazone

A Praveen Kumar, P Raveendra Reddy* & V Krishna Reddy

Received 7 March 2007, revised 31 August 2007

2-Hydroxy-3-methoxy benzaldehyde thiosemicarbazone has been synthesized, characterized and its analytical application investigated. It reacts with nickel(II) in aqueous solution at pH 4.0-8.0 and at room temperature to form a yellow coloured ML (1:1) complex with absorption maximum at 410 nm and molar absorptivity 2.05´104 l mol-1 cm-1. Beer’s law is obeyed in the range of 0.058-2.347 μg ml-1 of Ni(II). A method for the deter­mination of nickel(II) by second order derivative spectrophoto­metry has also been proposed. Interference of various diverse ions has been studied. The proposed methods have been successfully applied to determination of nickel in aluminium-based steels, drinking water, plant samples and in vegetable oil.

IPC Code: Int. Cl.8 G01N21/25

 

Indian Journal of Chemistry

Vol. 46A, October 2007, pp. 1630-1634

 

Determination of pKa’s of hydroxamic acids by nucleophilic substitution reaction

Ashish  Shrivastava, Kallol K. Ghosh & D. K. Dubey

Received 10 April 2007; Revised 27 August 2007

Acid dissociation constant (pKa) of some para-substituted benzohydroxamic4-XC6H4CONHOH, and N-methyl para-substituted benzohydroxamic acids, 4- XC6H4CON(OH)CH3, where X = H, CH3, CH3O, NO2, Cl, have been determined spectrophotometrically by nucleophilic substitution reactions of p-nitrophenyl acetate with hydroxamate ions at 27± 0.1oC. All reactions in this study follow pseudo-first order kinetics under condition of excess nucleophile. Good correlation has been observed between pKa and substitutent constants pointing out the validity of the Hammett equation. The kinetics results have been discussed on the basis of pKa and a-effect of hydroxamic acids.