Indian Journal of Chemistry

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

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VOLUME 48A

NUMBER 2

February 2009

CONTENTS

 

161

 

Structural, optical, photoluminescence and photocatalytic characteristics of sol-gel derived CeO2-TiO2 films

 

 

 

 

 

 

 

 

 

 

 

 

 

Amita Verma* & Amish G Joshi

 

 

 

 

CeO2-TiO2 films with different Ce/Ti mole ratios have been obtained by a sol-gel process. The films (1:0.25 and 1:0.5) containing more than 50% CeO2 content show nanocrystalline characteristics. The 1:0.5 film exhibits the best photoluminescence response, while the best photocatalytic activity is shown by the 1:3 film.

 

 

 

168

 

Influence of rare earths on activity and selectivity of hydrogenation of chloronitrobenzene over PtM/C
(M = La, Ce, Pr, Nd and Sm) catalysts

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Xiaoxiang Han

 

 

 

 

Hydrogenation of chloronitrobenzene has been studied over Pt/C and PtM/C catalysts (M = Sm, Pr, Ce, Nd and La) in ethanol at 303 K and normal pressure. The conversion of chloronitrobenzene over the catalysts is >99% and chloroaniline is the main product. PtCe/C exhibits the best catalytic activity (TOF = 0.47 s-1) and gives the highest yield of p-CAN (96.6 mol%), while PtLa/C gives the best yield for m-chloroaniline (95.8 mol%) and
o-chloroaniline (96.5 mol%).

 

 

 

173

 

Synthesis, characterization and superoxide dismutase activity of a series of copper(II) complexes containing NNO donor Schiff base and benzimidazole ligands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R N Patel

 

 

 

 

Synthesis and characterization of some mixed
ligand copper(II) complexes, viz., [Cu(BPS)(ImH)](ClO4), [Cu(BPS)(MeImH)](ClO4), [Cu(BPS)(EtImH)](ClO4), [Cu(BPS)(BenzImH)]ClO4.0.5H2O and [Cu(BPS)(MeBenzImH)]ClO4, (where BPS = benzoylpyridine 4-phenylsemicarbazone and
ImH = imidazole) are reported. The complexes show the presence of a distorted square planar CuN2O2 coordination geometry. Superoxide dismutase activity of these complexes has also been studied.

 

[Cu(BPS)(BenzImH)]ClO4.0.5H2O

 

 

181

 

On the distorted {NiN6} octahedron in hexakis(imidazole)nickel(II) bis(4-nitrobenzoate) dihydrate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bikshandarkoil R Srinivasan*, Jyoti V Sawant & Pallepogu Raghavaiah

 

 

 

 

The reaction of [Ni(H2O)6]Cl2 with the sodium salt of
4-nitrobenzoic acid in the presence of imidazole results in the formation of hexakis(imidazole)nickel(II) bis(4-nitrobenzoate) dihydrate. The complex crystallizes in the centrosymmetric triclinic space group Pī with the Ni(II) situated on an inversion center with a distorted octahedral hexakis(imidazole)nickel(II) cation. The distortion of the {NiN6} octahedron is discussed in terms of the difference between the longest and shortest Ni-N bonds.

 

 

 

 

189

 

Kinetics of permanganate oxidation of synthetic macromolecule poly(vinyl alcohol)

 

 

 

 

 

 

 

Maqsood Ahmad Malik, Mohammad Ilyas &
Zaheer Khan*

 

 

 

 

Oxidation of poly(vinyl alcohol) by MnO4- follows complex and fractional order kinetics with respect to [H2SO4] and [PVA] respectively. Water soluble colloidal MnO2 is formed as an intermediate. The overall rate law is given by:

 

 

Notes

 

194

 

Energetic properties of fluoranthenes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ivan Gutman*, Jelena Đurđević,
Slavko Radenković & Adrijana Burmudžija

 

 

 

 

The structure dependence of the total p-electron energy of fluoranthenes has been established. The joinder energy, i. e., the difference between the total p-electron energy of a fluoranthene and its two benzenoid units is discussed.

 

 

 

198

 

Electrochemical fabrication and characterization of poly(o-phenylenediamine) nanotubes by template method

 

 

 

 

 

 

 

 

 

 

 

 

T Maiyalagan & B Viswanathan*

 

 

 

 

The fabrication of conducting poly(o-phenylenediamine) nanotubes by electropolymerisation on alumina wafers is described. The polymer nanotubes have uniform and well-aligned arrays and their diameter and length match with the aspect ratios of the anodisc aluminium oxide membrane.

 

 

 

202

 

Preparation of La0.95Ce0.05CoO3 with large surface area

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yuehui Wu* & Laitao Luo

 

 

 

 

Perovskite-type complex oxides, La0.95Ce0.05CoO3, have been prepared by glycine polyacrylamide sol-gel combustion method, glycine sol-gel method and solid state reaction method. La0.95Ce0.05CoO3 prepared by glycine polyacrylamide sol-gel combustion method shows the highest catalytic activity for combustion of methane.

 

 

206

 

Numerical modelling and simulation of Koutecky-Levich equation for NADH electrocatalytic oxidation at graphite electrodes modified with a new polymeric phenothiazine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mihaela Ligia Unguresan* & Delia Maria Gligor

 

 

 

A mathematical model has been developed for the electrocatalytic NADH oxidation process at graphite electrodes modified with a polymer of phenothiazine formaldehyde. Numerical simulation of the kinetic parameters corresponding to electrocatalytic oxidation of NADH, using the modified graphite electrode has been obtained. The experimental data overlap almost perfectly with the mathematical and numerical simulated data.

 

 

 

211

 

A comparative study on the oscillatory behaviour of isomers of hydroxybenzoic acid with and without methyl ketones

 

 

 

 

 

 

 


Masood A Nath*, R P Rastogi & G M Peerzada

 

 

 

 

The oscillatory behaviour of isomers of hydroxybenzoic acid has been studied in 1.0 M H2SO4 with and without methyl ketones as mixed substrates. The presence of Br- and the critical bromide ion concentration play a key role. Ketones such as acetone, butanone and pentanone affect the oscillatory characteristics such as induction period, time period, frequency and number of oscillations. The oscillations arise in such systems provided the inhibitory reaction and autocatalysis balance each other.

 

 

 

 

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 161-167

 

 

Structural, optical, photoluminescence and photocatalytic characteristics of
sol-gel derived CeO2-TiO2 films

Amita Verma* & Amish G Joshi

Electronic Materials Division, National Physical Laboratory, New Delhi 110 012, India

Email: amitaverma75@gmail.com

Received 23 June 2008; revised and accepted 12 January 2009

CeO2-TiO2 films with different Ce/Ti mole ratios have been obtained using a simple sol-gel process. The films (1:0.25 and 1:0.5) containing more than 50% CeO2 content show nanocrystalline characteristics. X-ray photoelectron spectroscopic study shows the variation of Ce4+/Ce3+ ratio with increasing TiO2 content. Films with greater CeO2 content exhibit higher porosity. The observed photoluminescence in the films is attributed to various defects resulting from crystallization and also to the relative amount of Ce3+ in the mixed oxide matrix. The transparency in the films appears to be inversely related to their photoluminescence activity, since the 1:0.5 film, which exhibits the best photoluminescence response, is incidentally also the least transparent film. The presence of photocatalytic activity in these films shows their potential use as an efficient photocatalyst.

Keywords: Photochemistry, Photoluminescence, Photocatalysis; Luminescence, Thin films, Films, Sol-gel process, Ceria, Titania

IPC Code: Int. Cl.8 B01J21/00; C01F17/00; C09K11/78; C01G23/00

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 168-172

 

 

Influence of rare earths on activity and selectivity of hydrogenation of chloronitrobenzene over PtM/C (M=La, Ce, Pr, Nd and Sm) catalysts

Xiaoxiang Han

Department of Applied Chemistry, College of Food Science & Biotechnology Engineering,
Zhejiang Gongshang University, Hangzhou, 310035, PR China

Received 12 June 2008: revised and accepted 12 January 2009

Hydrogenation of chloronitrobenzene has been studied over Pt/C and PtM/C catalysts (M= Sm, Pr, Ce, Nd and La) in ethanol at 303 K and normal pressure. The effect of substrate concentration and reaction temperature has also been investigated over PtCe/C catalyst. The hydrogenation has been carried out over Pt/C catalyst. The order of the hydrogenation of choloronitrobenzene is p>o>m, and that of the yield of chloroaniline is: p>o>m. The conversion of chloronitrobenzene is >99% and chloroaniline is the main product on hydrogenation over PtM/C catalysts. PtCe/C catalyst exhibits the best catalytic activity (TOF = 0.47 s-1) and the highest yield of p-CAN (96.6 mol%). PtLa/C catalyst gives the best yield for m-chloroaniline (95.8 mol%) and o-chloroaniline (96.5 mol%). PtCe/C (0.1 wt%) catalyst exhibits good catalytic activity and stability on the hydrogenation of p-chloronitrobenzene.

Keywords: Catalysts, Hydrogenation, Haloamines, Chloronitrobenzene, Rare earths, Cerium, Lanthanum, Neodymium, Praseodymium, Samarium

IPC Code: Int. Cl.8 B01J23/10; B01J23/63; C07B35/00

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 173-180

 

 

Synthesis, characterization and superoxide dismutase activity of a series of copper(II) complexes containing NNO donor Schiff base and benzimidazole ligands

R N Patel

Department of Chemistry, A P S University, Rewa (M P) 486 003, India

Email: rnp64@yahoo.co.uk

Received 22 October 2008; revised and accepted 9 January 2009

Several mixed ligand copper(II) complexes, viz., [Cu(BPS)(ImH)](ClO4) (1), [Cu(BPS)(MeImH)](ClO4) (2), [Cu(BPS) (EtImH)](ClO4) (3), [Cu(BPS)(BenzImH)]ClO4.0.5H2O (4) and [Cu(BPS)(MeBenzImH)]ClO4 (5), where BPS = benzoylpyridine 4-phenylsemicarbazone, ImH = imidazole, MeImH = 2-methylimidazole, EtImH = 2-ethylimidazole, BenzImH = benzimidazole, MeBenzImH = 2-methylbenzimidazole have been synthesized and characterized by the elemental analysis, molar conductance measurements, magnetic susceptibility measurements, FAB mass, IR, electronic, EPR spectral and cyclic voltammetric studies. The BenzImH complex (4) is structurally characterized by single crystal X-ray crystallography. Complex (4) crystallizes in the triclinic space group P-1 with unit cell parameters: a = 10.104(3, b = 10.924(3)Ǻ, c = 13.128(3)Ǻ, α = 80.21(2) , β = 70.63(3), γ = 89.61(2) and Z = 2. The one electron paramagnetic complexes show a d-d band near 700nm in DMSO and a cyclic voltammetric response due to Cu(II)/Cu(I) couple. The complexes show the presence of a distorted square planar CuN2O2 coordination geometry. Superoxide dismutase activity of the present complexes has also been studied.

Keywords: Coordination chemistry, Schiff bases, Imidazoles, Benzimidazoles, Copper

IPC Code: Int. Cl.8 C07C251/02; C07F1/08

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 181-188

 

 

On the distorted {NiN6} octahedron in hexakis(imidazole)nickel(II)

bis(4-nitrobenzoate) dihydrate

Bikshandarkoil R Srinivasana, *, Jyoti V Sawanta & Pallepogu Raghavaiahb

aDepartment of Chemistry, Goa University, Goa 403 206 India

Email: srini@unigoa.ac.in

bSchool of Chemistry, University of Hyderabad, Hyderabad 500 046, India

Received 21 May 2008; revised and accepted 22 December 2008

The reaction of [Ni(H2O)6]Cl2 with the sodium salt of 4-nitrobenzoic acid (4-nbaH) in the presence of imidazole results in the formation of the title compound hexakis(imidazole)nickel(II) bis(4-nitrobenzoate) dihydrate (1). Compound (1) is dehydrated to hexakis(imidazole)nickel(II) bis(4-nitrobenzoate) (2) by heating at 100oC. Both compounds are characterized by elemental analysis, infrared spectra, X-ray powder pattern and thermal studies. The title compound [Ni(Im)6](4-nba)2.2H2O (1) crystallizes in the centrosymmetric triclinic space group Pī with the Ni(II) situated on an inversion center. The structure of (1) consists of a distorted octahedral hexakis(imidazole)nickel(II) cation, a free uncoordinated 4-nba anion and a lattice water with half of the molecule accounting for the asymmetric unit. In the complex cation the central metal is bonded to six neutral terminal Im ligands. The distortion of the {NiN6}octahedron in (1) is discussed in terms of the difference between the longest and shortest Ni-N bonds. A comparative study of several [Ni(Im)6]2+ compounds in different structural environments is described. In the crystal structure, the cation, anion and lattice water are linked by three types of H-bonding interactions comprising two O-HO, three N-HO and three C-HO interactions. Each hexacoordinated Ni(II) complex cation is linked to eight symmetry related 4-nba anions and four different lattice water molecules via N-HO and C-HO interactions, while each 4-nba anion is H-bonded to four complex cations and two symmetry related lattice water molecules. Pairs of [Ni(Im)6]2+ cations and 4-nba anions are linked to lattice water molecules via O-HO and C-HO interactions. As a result of the hydrogen bonding interactions, the cations and anions are organized into alternating layers.

Keywords: Coordination chemistry, Hydrogen bonding interactions; Crystal structure, Imidazoles, Nitrobenzoates, Nickel

IPC Code: Int. Cl.8: C07F15/04

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 189-193

 

 

Kinetics of permanganate oxidation of synthetic macromolecule poly(vinyl alcohol)

 

Maqsood Ahmad Malik, Mohammad Ilyas & Zaheer Khan*

aDepartment of Chemistry, Jamia Millia Islamia (Central University), Jamia Nagar, New Delhi, 110 025, India

Email: drkhanchem@yahoo.co.in

Received 22 July 2008; re-revised and accepted 27 December 2008

Oxidation of poly(vinyl alcohol) (PVA) by permanganate has been studied spectrophotometrically at 525 and 420nm. Under pseudo-first order conditions ([PVA] >> [MnO4-]), the reaction rate increases with [PVA] and the kinetics reveals complex order dependence on [PVA]. The second-order kinetics with respect to [H2SO4] at low concentration shifts to first-order at higher concentration. Water soluble colloidal MnO2 has been identified as an intermediate in the reduction of MnO4- by PVA. The hydrogen ions decrease the stability of colloidal MnO2. Poly(vinyl ketone) is found to be the final oxidation product of PVA. Inorganic electrolytes like NaF, Na4P2O7 and MnCl2 (a product of the reaction), have inhibitory and composite effects (inhibition and catalysis) on the reaction rate. Arrhenius and Eyring equations have been used to evaluate the activation parameters. The observed results are discussed in terms of Michaelis-Menten kinetic model. A mechanism has been proposed on the basis of experimental findings.

Keywords: Kinetics, Reaction mechanisms, Oxidations, Poly(vinyl alcohol), Permanganate oxidations

 

IPC Code: Int Cl.8 C07B33/00

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 194-197

 

 

Energetic properties of fluoranthenes

 

Ivan Gutman*, Jelena Đurđević, Slavko Radenković & Adrijana Burmudžija

Faculty of Science, P.O. Box 60, 34000 Kragujevac, Serbia

Email: gutman@kg.ac.yu

Received 3 October 2008; accepted 5 January 2009

Fluoranthenes form a class of polycyclic conjugated molecules, structurally very similar to benzenoid systems. They consist of two benzenoid units joined through a five-membered ring. The basic features of the structure dependence of the total π-electron energy of fluoranthenes have been established. The focus of the studies is on the joinder energy, i.e., the difference between the total π-electron energy of a fluoranthene and of its two benzenoid units.

KeywordsTheoretical chemistry, Graph theory, Topological studies, Hydrocarbons, Benzenoids, Fluoranthenes,

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 198-201

 

 

Electrochemical fabrication and characterization of poly(o- poly(o-phenylenediamine) nanotubes by template method

T Maiyalagan & B Viswanathan*

National Centre for Catalysis Research, Department of Chemistry,

Indian Institute of Technology Madras, Chennai 600 036, India

Email: bvnathan@iitm.ac.in

Received 20 October 2008; revised 9 January 2009

The fabrication of conducting poly (o-phenylenediamine) nanotube by electropolymerisation on alumina wafers (Whatman Anodisc 47 filter disk) is described. The nanotubes have been characterized by FTIR, UV-vis, SEM, TEM and AFM studies. SEM and TEM results reveal that the polymer nanotubes have uniform and well-aligned arrays and their diameter and length match with the aspect ratios of the anodisc aluminium oxide (AAO) membrane.

Keywords:Conductingpolymers,Electropolymerization, Nanomaterials, Nanotube arrays, Template method, Poly o- phenylenediamine

IPC Code: Int. Cl.8 B82B1/00; C08G73/00; C25B3/02

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 202-205

 

 

 Preparation of La0.95Ce0.05CoO3 with large surface area

Yuehui Wua,* & Laitao Luob

aDepartment of Materials Chemistry,
Nanchang Hangkong University,
NanChang 330063, PR China
bInstitute of Applied Chemistry, Nanchang University,
NanChang 330069, PR China

Email: wuyuehui_c@ sina.com

Received 29 July 2008; revised and accepted 13 January 2009

The perovskite-type complex oxides, La0.95Ce0.05CoO3, have been prepared by glycine polyacrylamide sol-gel combustion method, glycine sol-gel method and solid state reaction method. These oxides have been used successfully for combustion of methane. The La0.95Ce0.05CoO3 samples have been investigated by XRD, BET,O2-TPD and H2-TPR. The effect of preparation method on the structure and performance of the catalysts has been studied. La0.95Ce0.05CoO3 prepared by glycine polyacrylamide sol-gel combustion method shows the highest catalytic activity for combustion of methane.

Keywords:Oxides, Perovskites, Catalysts, Methane combustion, Lanthanum, Cerium, Cobalt

IPC code: Int. Cl.8 B01J23/75; C01G51/04; C01G57/00; C01J23/75

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 206-210

 

 

Numerical modelling and simulation of Koutecky-Levich equation for NADH electrocatalytic oxidation at graphite electrodes modified with a
new polymeric phenothiazine

Mihaela Ligia Unguresana, * & Delia Maria Gligorb

aChemical Department, Technical University of Cluj-Napoca, 400641 Cluj-Napoca, Romania

Email: Mihaela.Unguresan@chem.utcluj.ro

bPhysical Chemistry Department, Babes Bolyai University, 400028 Cluj-Napoca, Romania

Received 27 August 2008; revised 26 December 2008

A mathematical model has been developed for the electrocatalytic NADH oxidation process taking place at graphite electrodes modified with a polymer of phenothiazine formaldehyde. The electrocatalytic rate constants (kobs) have been obtained from rotating disk electrode experiments, at various concentrations of NADH and pH values of the supporting electrolyte. Using the method of linear regression, the kinetic parameters kobs[NADH]=0, k+2 and KM have been determined. Based on the results obtained, the numerical simulation of these parameters corresponding to electrocatalytic oxidation of NADH, using the modified graphite electrode, has been obtained. The experimental data overlap almost perfectly with the mathematical and numerical simulated data, proving the validity of the model.

Keywords: Electrochemistry, Modified electrodes, Polymers, Electrocatalytic oxidations, Oxidations, Koutecky-Levich approach, Polyphenothiazine, formaldehyde

IPC Code: Int. Cl.8 C07B33/00; C25B3/00; H01M4/96

 

 

Indian Journal of Chemistry

Vol. 48A, February 2009, pp. 211-214

 

 

A comparative study on the oscillatory behaviour of isomers of hydroxybenzoic acid with and without methyl ketones

Masood A Natha,*, R P Rastogib G M Peerzadaa

aDepartment of Chemistry, University of Kashmir,
Srinagar 190 006, India

bBanaras Hindu University, Varanasi 221 005, India

Email: nath_masood@yahoo.co.in/peerzada_gmp@yahoo.co.in

Received 5 March 2008; revised and accepted 9 January 2009

The oscillatory behaviour of isomers of hydroxybenzoic acid has been studied in 1.0 M H2SO4 with and without methyl ketones as mixed substrates. The presence of Br and the critical bromide ion concentration have been found to have a key role in the present study. Moreover, the effect of ketones such as acetone, butanone and pentanone has also been found to affect the oscillatory characteristics such as induction period, time period, frequency and number of oscillations. The oscillations arise in such systems provided the inhibitory reaction and autocatalysis balance each other.

Keywords: Oscillatory reactions, Hydroxybenzoic acids, Methyl ketones