Indian Journal of Chemistry

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

 

VOLUME 46A

NUMBER 9

September 2007

 

CONTENTS

 

Advances in Contemporary Research

 

1373

 

Analytical applications of thiacalixarenes: A Review

 

 

 

 

 

 

 

 

 

 

Y K Agrawal* & J P Pancholi

 

 

 

 

Thiacalixarenes have a wide range of functions, conformational flexibility and chemical behaviour, which increases the importance of these compounds in supramolecular chemistry. Analytical applications of various thiacalixarenes with their derivatives have been discussed. The metal binding affinities of such thiacalixarenes have been summarized.

 

Papers

 

1383

 

Highly accurate Gaussian basis sets for low-lying excited states of some positive and negative ions

 

 

 

 

 

 

 

 

 

P J P de Oliveira & F E Jorge*

 

 

 

 

The improved generator coordinate Hartree-Fock method has been used to generate highly accurate Gaussian basis sets for low-lying excited states of some mono positive and negative ions. From these basis sets, total HF energies have been calculated and compared with results reported in the literature.

 

1388

 

A new approach to predicting the carbonyl stretching frequencies of Co2(CO)8 with
D3d symmetry

 

 

 

 

 

 

 

 

 

 

 

 

 

Cemal Kaya*, Duran Karakaş & Elvan Üstün

 

 

 

 

A method for determining C-O stretching frequencies of dicobalt octacarbonyl belonging to D3d point group has been described. The method is based on the variation of fundamental C-O stretching frequencies and C-O stretching force constants of axially substituted X3MCo(CO)4 (M=Si, Ge, Sn and Pb; X=Cl, Ph and Et) molecules with the dipole moment of X3M-Co(CO)4 bond. The study shows that there exists a linear correlation between
C-O stretching force constants of X3MCo(CO)4 complexes and dipole moment of X3M-Co(CO)4 bond, which allows the calculation of C-O stretching force constants (k1 and k2) and frequencies of a1g(2) and eg modes of Co2(CO)8.

 

1393

 

Synthesis, structure and luminescence behaviour of copper(II)cyanato complexes containing bidentate N-donor Schiff bases

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Habibar Chowdhury, Rajarshi Ghosh*,
Bhola Nath Sarkar , Sankar Prasad Banerjee & Barindra Kumar Ghosh*

 

 

 

 

Two Schiff bases, N-((pyridin-2-yl)formylidene)benzylamine  and N-((pyridin-2-yl)benzylidene)benzylamine have been prepared and used to synthesize four pentacoordinated copper(II)cyanato complexes of the type, [Cu(L)2(NCO)]X
[X = ClO4
-, PF6-].

 

1401

 

Synthesis, structure and properties of
(4,4'-H2bipy)[ZnBr4]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yiming Xie* & Jihuai Wu

 

 

 

 

[4,4¢-H2bipy][ZnBr4], exhibits an isolated structure based on discrete 4,4¢-H2bipy moieties and tetrahedral metal(II) centre terminally coordinated by four bromide ions. The organic moieties and the inorganic complex dianions are linked via hydrogen bonds forming a sheet structure.

 

 

1406

 

Spectral and structural studies of S-methyl and
S-benzyl dithiocarbazate azomethine complexes of lanthanum

 

 

 

 

 

 

 

 

 

 

Ritu Singh, S P Mittal, Sachin Malik  & R V Singh*

 

 

 

 

Bibasic tridentate azomethine ligands, namely, S-methyl dithiocarbazate and S-benzyl dithiocarbazate react with lanthanum isopropoxide in anhydrous benzene liberating different amounts of isopropanol depending on the stoichiometry (1:1, 2:3 and 1:2).

 

 

Notes

 

1414

 

Free radical graft polymerization of methyl methacrylate from polyvinyl alcohol using FeCl3/K2S2O5 redox pair

 

 

 

 

 

 

 

 

P Chowdhury*, Md A Ali & K Roy

 

 

 

 

Ferric chloride/potassium metabisulfite redox pair initiated free radical polymerization of methyl methacrylate has been carried out in aqueous medium, both in the presence and absence of polyvinyl alcohol. The presence of polyvinyl alcohol (0.1%) gives more than 70 % yield of polymethyl methacrylate homopolymer. About 60 % graft copolymer (PVOH-g-PMMA) is obtained at 0O C using 1.0 % PVOH.

 

1419

 

Refractometric study of polymers and their blends in solution

 

 

 

 

 

 

 

 

R J Sengwa*, Sonu Sankhla & Shobha Sharma

 

 

 

 

Refractive indices of poly(vinyl pyrrolidone), poly(vinyl alcohol) and poly(ethylene glycol) in solution at 298 K are reported. High frequency limiting dielectric constant, taken as the square of the measured refractive index, shows concentration dependent linear behaviour.

 

 

1423

 

Synthesis and characterization of dinuclear molybdenum(VI) peroxo complexes with aroyl hydrazones

 

 

 

 

 

 

 

 

 

 

 

 

Mohd Saleem, Mohita Sharma, H N Sheikh* & B L Kalsotra

 

 

 

 

The reaction of ammonium molybdate with hydrogen peroxide and ethanolic solutions of aroylhydrazones, results in  precipitation of the dinuclear complexes, Mo2O4(O2)2L-L(H2O)4. The dinuclear complexes have been found to preserve the individuality of the molybdenum oxo peroxo core.

 

 

1427

 

Oxidation of aspartic acid by water soluble colloidal MnO2 in absence and presence of ionic and nonionic surfactants

 

 

 

 

 

 

 

Mohd. Akram, Mohammad Altaf & Kabir-ud-Din*

 

 

 

 

Kinetics of oxidation of aspartic acid by water-soluble form of colloidal manganese dioxide has been studied in acidic perchlorate media. The reaction is first-order in both [MnO2] and [aspartic acid] but fractional order in [HClO­4]. The results suggest the formation of an adsorption complex between aspartic acid and MnO, which decomposes in a rate-determining step, leading to the formation of a free radical, which again reacts with the colloidal MnO2 in a subsequent fast step to yield the product.

 

1432

 

Derivative spectrophotometry for determination of zinc(II) and cadmium(II) using diphenylcarbazone in presence of Triton X-100

 

 

 

 

 

Varinder Kaur, Ashok Kumar Malik*,
Neelam Verma & A L J Rao

 

 

 

 

Diphenylcarbazone has been used for the simultaneous and individual determination of zinc(II) and cadmium(II) at trace levels. A zero crossing method using fourth derivative at 493.5 nm and 448.5 nm has been used for simultaneous determination of Zn(II) and Cd(II) respectively.

 

 

1437

 

Synthesis and anion recognition of acetate ions using 1-(a-pyrrolyl)-2,4-dinitrophenyl hydrazone

 

 

 

 

 

 

 

Ming Yu, Hai Lin & Huakuan Lin*

 

 

 

 

A pyrrol based anion receptor with high selectivity for acetate ions has been synthesized. Anion binding studies have been carried out using 1H NMR and UV-vis spectra. The results indicate that deprotonation takes place after the receptor binds to      CH3COO-.

 

 

1440

 

Photochemistry of 6-chloro-3-hydroxy-2-(2¢-thienyl)-4-oxo-4H-1-benzopyran

 

 

 

 

 

 

Ritu Bala, Rupesh Kumar, Mohamad Yusuf & W R Bansal*

 

 

 

 

On photolysis of 6-chloro-3-hydroxy-2-(2¢-thienyl)-4-oxo-4H-1-benzopyran around its λmax (360 nm), it rearranges to 6-chloro-3-hydroxy-3-(2¢-thienyl)-1,2-indandione as analysed by IR, NMR and by coupling with o-phenylenediamine. Quantum yield of the product is low (~0.05), which is not affected by the polarity of the solvent.

 

 

Authors for correspondence are indicated by (*)


 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1373-1382

 

Analytical applications of thiacalixarenes: A Review

Y K Agrawal* & J P Pancholi

Received 2 July 2007; revised 27 July 2007

Analytical applications of various thiacalixarenes with their derivatives have been discussed. The metal binding affinities of such thiacalixarenes have been summarized.

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1383-1387

 

Highly accurate Gaussian basis sets for low-lying excited states of some positive and negative ions

P J P de Oliveira & F E Jorge*

Received 18 January 2007; revised 7 August 2007

The improved generator coordinate Hartree-Fock (HF) method has been used to generate highly accurate Gaussian basis sets for low-lying excited states of some mono-positive and -negative ions. From these basis sets, total HF energies have been calculated and compared with results reported in the literature. The accuracy of HF energy achieved herein is the best so far obtained with finite basis set expansion of Gaussian-type functions (GTFs). Using GTFs, difference between corresponding energies calculated with our sets and those reported in the literature is achieved up to 13.8 mhartree.

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1388-1392

 

A new approach to predicting the carbonyl stretching frequencies ofCo2(CO)8 with D3d symmetry

Cemal Kaya*, Duran Karakaş & Elvan Üstün

Received 2 March 2007; revised 29 July 2007

This paper describes a method for determining C-O stretching frequencies of dicobalt octacarbonyl belonging to D3d point group. The method is based on the variation of fundamental C-O stretching frequencies and C-O stretching force constants of axially substituted X3MCo(CO)4 (M=Si, Ge, Sn and Pb; X=Cl, Ph and Et) molecules with the dipole moment of X3M-Co(CO)4 bond. Frequencies of a1g(1), a2u(2)  and eu modes have been evaluated from the graph of frequency versus dipole moment, and the frequencies of a1g(2) and eg modes determined from the equations derived by using the CO-factored force field. The calculated frequencies have been found to be consistent with the experimental values. With the use of the calculated frequencies, the C-O factored force constants of Co2(CO)8 with D3d symmetry have been calculated. In addition, frequencies of mono-13CO substituted species of Co2(CO)8 have been estimated and compared with observed frequencies of the species.

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1393-1400

 

Synthesis, structure and luminescence behaviour of copper(II)cyanato complexes containing bidentate N-donor Schiff bases

Habibar Chowdhury, Rajarshi Ghosh*, Bhola Nath Sarkar , Sankar Prasad Banerjee & Barindra Kumar Ghosh*

Received 18 June 2007; accepted 1 August 2007

Two Schiff bases, N-[(pyridin-2-yl)formylidene]benzylamine (pfba) and N-[(pyridin-2-yl)benzylidene]benzylamine (pbba) have been prepared and used to synthesize four pentacoordinated copper(II)cyanato complexes of type [Cu(L)2(NCO)]X (1-4) [L = pfba, X = ClO4-, 1; L = pfba, X = PF6-, 2; L = pbba, X = ClO4-, 3; L = pbba, X = PF6-, 4]. The complexes have been characterized on the basis of microanalytical, spectroscopic, magnetic, electrochemical and other physicochemical properties. Structure of [Cu(pbba)2(NCO)]ClO4 (3) has been solved by X-ray diffraction measurement. Structural analysis reveals that the copper(II) centre in 3 has a distorted trigonal bipyramidal geometry with a CuN5 chromophore coordinated through four N atoms of two bidentate pbba units and one N atom of terminal cyanate. 3 forms a one-dimensional chain through C-H…O hydrogen bond, pp and C-H…p interactions. The complexes 1-4 exhibit d-d transition and n-p*/p-p* charge transfer transition. Electrochemical electron transfer study reveals copper(II)-copper(I) reduction in methanolic solutions. High-energy intraligand 1(p-p*) fluorescence at room temperature and intraligand 3(p-p*) phosphorescence in glassy solutions (MeOH at 77 K) and in solid states are seen in all the complexes.

IPC Code: Int. Cl.8 C07C25/02; C07F1/08

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1401-1405

 

Synthesis, structure and properties of (4,4'-H2bipy)[ZnBr4]

Yiming Xie* & Jihuai Wu

Received 16 April 2007; revised 7 August 2007

The compound [4,4¢-H2bipy][ZnBr4] (1) has been synthesized via hydrothermal reaction and exhibits an isolated structure based on discrete 4,4¢-H2bipy moieties and tetrahedral metal(II) centre terminally coordinated by four bromide ions. The organic moieties and the inorganic complex dianions are linked via hydrogen bonds forming a sheet structure. Optical absorption spectrum shows a band gap of 3.13 eV, indicating 1 to be a wide gap semiconductor. Luminescent investigation reveals a strong emission in blue region, which may be originating from p®p* charge-transfer interaction of 4,4¢-H2bipy. IR, powder X-ray diffraction (PXRD) and thermogravimetry-differential thermal analyses (TG-DTA) are also reported.

IPC Code: Int. Cl.8 C07F3/06

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1406-1413

 

Spectral and structural studies of S-methyl and S-benzyl dithiocarbazate azomethine complexes of lanthanum

Ritu Singh, S P Mittal, Sachin Malik & R V Singh*

Received  30 March 2007; revised 2 August 2007

Synthesis and characterization of different types of lanthanum(III) complexes with azomethines are reported here. Bibasic tridentate azomethine ligands namely S-methyl dithiocarbazate (DTCZ1H2) and S-benzyl dithiocarbazate (DTCZ2H2) react with lanthanum isopropoxide in anhydrous benzene liberating different amounts of moles of isopropanol depending on the stoichiometry (1:1, 2:3 and 1:2). The derivatives have been characterized by the elemental analyses, magnetic susceptibility and spectral studies including IR, 1H NMR and electronic spectra. The X-ray diffraction studies of these complexes have also been carried out to establish their molecular symmetry and lattice constants. The complexes are highly hygroscopic and become sticky when exposed to the open atmosphere due to the presence of labile isopropoxy groups. The X-ray studies reveal that these complexes crystallize in orthorhombic molecular symmetry.

IPC Code: Int. Cl.8 C07F17/00

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1414-1418

 

Free radical graft polymerization of methyl methacrylate from polyvinyl alcohol using FeCl3/K2S2O5 redox pair

P Chowdhury*, Md A Ali & K Roy

Received 22 March 2006; revised 9 June 2007

Ferric chloride/potassium metabisulfite redox pair initiated free radical polymerization of methyl methacrylate has been carried out in aqueous medium both in presence and absence of polyvinyl alcohol (PVOH). The percentage of homopolymer formation is very low in absence of PVOH. However, the presence of PVOH (0.1%) gives rise to more than 70 % yield of polymethyl methacrylate homopolymer. About 60% graft copolymer (PVOH-g-PMMA) is achieved at 0°C using 1.0 % PVOH. Free radical polymerization (both homopolymer and graft copolymer) is decreased with the increase of temperature. Homopolymer formation and graft co-polymerization have been confirmed by FT-IR studies. A reaction scheme has been proposed to elucidate the role of ferric ion and metabisulfite ion.

IPC Code: Int Cl. 8 C08F4/40; C08F16/06; C08F265/00

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1419-1422

 

Refractometric study of polymers and their blends in solution

R J Sengwa,*, Sonu Sankhla & Shobha Sharma

Received 22 March 2007; revised 18 July 2007

Measurement of refractive index (nD) of poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG) in solution at 298 K is presented here. PVP has been investigated in nine different polar solvents including liquid PEG200 and PEG400, whereas PVA, PEG, and PVP+PVA and PVP+PEG blend have been investigated in water solution. High frequency limiting dielectric constant (e¥) has been taken as the square of the measured refractive index (). It is observed that the concentration dependent e¥ values of these systems exhibit linear behaviour. The e¥ values of the pure polymers have been determined from the measured e¥ values of their polymeric solutions. The effect of molecular weight of the polymers on the electronic polarization is discussed by considering comparative e¥ values of different molecular weight polymers. Results reveal that these polymers and their blends have high solubility in the used solvents, which is mainly due to the polymer-solvent hydrogen bond interactions.

IPC Code: Int. Cl.8 G01N21/00

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1423-1426

 

Synthesis and characterization of dinuclear molybdenum(VI) peroxo complexes with aroyl hydrazones

Mohd Saleem, Mohita Sharma, H N Sheikh* & B L Kalsotra

Received 13 April 2007; revised 6 August 2007

The reactions of ammonium molybdate with hydrogen peroxide and ethanolic solutions of aroylhydrazones, viz. benzoic acid [1-(Furan-2-yl) methylene] hydrazide (BFMH), benzoic acid [(thiophen-2-yl)methylene] hydrazide (BTMH), benzoic acid [1-(thiophen-2-yl) ethylidene] hydrazide (BTEH), benzoic acid (phenyl methylene) hydrazide (BPMH) and benzoic acid [1-(anisol-3-yl) methylene] hydrazide (BAMH), result in the precipitation of the dinuclear complexes, Mo2O4(O2)2L-L(H2O)4 (where L-L = BFMH, BTMH, BTEH, BPMH and BAMH). The complexes have been characterized by elemental analysis, and studies on conductivity and magnetic susceptibility, IR and electronic spectra, 1H NMR spectra, and TGA/DTA. The dinuclear complexes have been found to preserve the individuality of the molybdenum oxo peroxo core. The complexes exhibit significant in vitro antifungal effects against the Keretolytic fungus as compared to ligands.

IPC Code: Int. Cl.8 C07F11/00

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1427-1431

 

Oxidation of aspartic acid by water soluble colloidal MnO2 in absence and presence of ionic and nonionic surfactants

Mohd. Akram, Mohammad Altaf & Kabir-ud-Din*

Received  20 March 2007; revised 12  August 2007

The kinetics of the oxidation of aspartic acid by water-soluble form of colloidal manganese dioxide has been studied in acidic perchlorate media. Monitoring the disappearance of the colloidal MnO2 spectrophotometrically at 390 nm has been used to follow the kinetics. The reaction is first-order in both [MnO2] and [aspartic acid] but fractional-order in [HClO­4]. The results suggest formation of an adsorption complex between aspartic acid and MnO2. The complex decomposes in a rate-determining step, leading to the formation of a free radical, which again reacts with the colloidal MnO2 in a subsequent fast step to yield the product. The anionic micelles of sodium dodecyl sulfate have no effect on the oxidation rate whereas the rate constant increased with increase in [TX-100] which has been explained in terms of mathematical model proposed by Tuncay et al. A mechanism in agreement with the observed kinetic results is proposed and discussed. Freundlich isotherm is used to explain the adsorption of aspartic acid on colloidal MnO. Different activation parameters (Ea, ∆H#, ∆S#) have been evaluated and discussed.

 

IPC Code: Int. Cl.8 C07B33/00

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1432-1436

 

Derivative spectrophotometry for determination of zinc(II) and cadmium(II) using diphenylcarbazone in presence of Triton X-100

Varinder Kaur, Ashok Kumar Malik*, Neelam Verma & A L J Rao

Received 10 May 2006; rerevised 3 August 2007

Diphenylcarbazone has been used for the simultaneous and individual determination of zinc(II) and cadmium(II) at trace levels. The carbazone complexes of zinc(II) and cadmium(II) at pH 7–10 are pink in color, and are soluble in TX-100 micellar media. Under optimum conditions, calibration graphs for individual and simultaneous determination by first, second, third and fourth derivative spectrophotometry has been obtained. A zero crossing method using fourth derivative at 493.5 nm and 448.5 nm has been used for simultaneous determination of Zn(II) and Cd(II) respectively. To investigate the selectivity of the method, the effects of diverse ions on the determination of zinc and cadmium have also been studied. The recommended procedure has been applied to synthetic binary alloys and pharmaceutical samples.

IPC Code: Int. Cl.8 G01N21/25

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1437-1439

 

Synthesis and anion recognition of acetate ions using pyrrole-α-carboxaldehyde 2, 4-dinitrophenyl hydrazone

Ming Yu, Hai Lin & Huakuan Lin*

Received 8 January 2007; revised 14 August 2007

A pyrrol-based anion receptor (1) for acetate ions has been designed and synthesized. The receptor has been characterized by various chemical methods. Anion binding studies have been carried out using 1H NMR and UV-vis spectra. The results indicate that deprotonation takes place after receptor 1 binds CH3COO-. 1 exhibits high selectivity for acetate ions for complementarity between the receptor and anion. The compound may be useful in the field of sensor materials.

 

Indian Journal of Chemistry

Vol. 46A, September 2007, pp. 1440-1444

 

Photochemistry of 6-chloro-3-hydroxy-2-(2¢-thienyl)-4-oxo-4H-1-benzopyran

Ritu Bala, Rupesh Kumar, Mohamad Yusuf & W R Bansal*

Received 26 February 2007; revised 23 July 2007

On photolysis of the titled compound around its λmax (360 nm), it rearranges to 6-chloro-3-hydroxy-3-(2¢-thienyl)-1,2-indandione as analysed by IR, NMR and by coupling with o-phenylenediamine. Quantitative analysis of the photolysed mixture by spectral measurements also confirms it. Quantum yield of the product is low (~0.05), which is not affected by the polarity of the solvent.