Indian Journal of Chemistry

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

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CODEN: ICACEC; ISSN: 0376-4710 (Print), 0975-0975 (Online)

 

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VOLUME 51A

NUMBER 5

MAY 2012

 

CONTENTS

 

 

669

 

Gas phase reactions of La+ with acetone: A density functional theory investigation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gui-hua Chen* & Danxia Liang

 

 

 

The singlet PES can provide a low energy reaction pathway towards the η2-CH3COCH3-metal complex 1IM1. The reaction is most likely to proceed through the following steps: 3La++CH3COCH33IM0→CP→1IM1.

 

 

 

 

676

 

Single-step synthesis and structural study of phosphate modified titania through seeding method

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K Joseph Antony Raj, T Elangovan & B Viswanathan*

 

 

 

A single-step organic-free process has been developed to prepare phosphate-modified titania from titanium oxysulphate solution at a temperature of about 98 °C using a seed. Spectral evidences show strong adsorption of phosphate as Ti-O-P on the titania surface.

 

 

 
681
 

Kinetic and mechanistic studies of oxidation of glycine and valine by N-bromosuccinimide using chloro complex of Rh(III) in its nano-concentration range as homogeneous catalyst

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ashok Kumar Singh*, Rajesh Kumar Singh,
Jaya Srivastava, Shahla Rahmani & Sarita Yadav

 

 

 

Kinetics of oxidation of glycine and valine by
N-bromosuccinimide using chloro complex of Rh(III) in its
nano-concentration range as homogeneous catalyst has been investigated at 35
oC . The reaction shows first order kinetics with respect to NBS and Rh(III) in the oxidation of both the
amino acids. The first order kinetics with respect to amino acid obtained at its lower concentration changes to zero order at
its higher concentration.

 

 

 

 

Notes

 

690

 

On atom-bond connectivity index and its
chemical applicability

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ivan Gutman*, Jelena Tošović, Slavko Radenković
& Svetlana Marković

 

 

 

The simple empirical formula DH°f = – (a+b·ABC) with a = 65.98, b = 20.37, reproduces the heat of formation with an accuracy comparable to that of high level ab initio and DFT (MP2, B3LYP) quantum chemical calculations

 

 

 

 

695

 

A global model to predict density of non-aqueous binary solvent mixtures at various temperatures

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Abolghasem Jouyban*, Seyed Hamed Maljaei,
Maryam Khoubnasabjafari & Anahita Fathi-Azarbayjani

 

 

 

The combined form of the Jouyban-Acree model and the calculated Abraham solute parameters have been used to predict the density of 290 binary solvent mixtures in the temperature range of 278.15 – 353.15 K.  The mean relative deviation of 1.2±1.9 % indicates that the proposed model, together with the calculated Abraham parameters, accurately reproduces the concentration and temperature dependence of density values of binary solvent mixtures.

 

 

 

 

 

 

699

 

In situ bismuth film modified carbon fiber microelectrode for nanomolar detection of cadmium and lead

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S Anandhakumar, J Mathiyarasu* & K L N Phani

 

 

 

The in situ bismuth film modified carbon fiber microelectrode proposed for sensitive detection of Cd(II) and Pb(II) in
0.1 M acetate buffer solution of pH 4.5 shows enhanced detection limits at nanomolar level for individual as well as simultaneous detection of the analytes.

 

 

 

 

 

 

704

 

Study of sulphonic acid functionalization of Vulcan XC-72 carbon black support of Pt/Vulcan XC-72 catalyst for methanol electrooxidation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sundar Chandravathanam, B Kavitha,
Balasubramanian Viswanathan* & Y Yesu Thangam

 

 

 

Sulphonic acid groups have been incorporated onto the carbon support of the Pt/VulcanXC-72 catalyst by reaction with formaldehyde and sodium sulphite. The increase in activity of the modified catalyst is attributed to better dispersion of the
Pt nanopaticles and increased protonic conductivity due to incorporation of sulphonic acid groups inside the
Vulcan XC-72 support.

 

 

 

 

 

 

 

708

 

Hydrothermal synthesis and characterization of lanthanide oxalates: In situ oxalate formation from tartaric acid in presence of KI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Muhammad Athar* & Ashfaq Mahmood Qureshi

 

 

 

Two new three-dimensional lanthanide oxalates [Pr2(C2O4)3(H2O)4]·2H2O and [Nd2(C2O4)3(H2O)4]·2H2O and a two-dimensional oxalate [Pr2(C2O4)3(H2O)6]·3H2O have been prepared by hydrothermal process and characterized by single crystal X-ray analysis. The two-dimensional oxalate is produced by the in situ hydrothermal degradation of tartaric acid to oxalate ions in presence of KI.

 

 

 

 

715

 

Guide to Authors

 

 

 

 

 

Authors for correspondence are indicated by (*)

 

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 669-675

 

Gas phase reactions of La+ with acetone: A density functional theory investigation

Gui-hua Chen* & Danxia Liang

School of Pharmaceutical and Chemical Engineering, Taizhou University, Linhai, 317000, PR China

Email: chenguihua518@hotmail.com

Received 20 September 2011; revised and accepted 10 April 2012

The gas phase reaction of La+ cation with acetone is investigated using density functional theory. Both ground and excited state potential energy surfaces are investigated in detail. The present results show that the title reaction starts with the formation of an O-attached complex (IM0). All possible pathways starting with C−O, C−H, and C−C activation have been searched. These reactions can lead to four different products, (1LaO++C3H6, 2LaCH2COCH3++H, 1LaCOCH2++CH4 and 1LaCH2++CH3CHO). The minimum energy reaction path is found to involve spin inversion after IM0 formation, and this potential energy curve-crossing dramatically affects the reaction exothermic. As all the triplet intermediates, transition states and products involved in the reaction lie below the ground reactants (3La++ CH3COCH3) after IM0 formation, the reaction is expected to occur spontaneously over the singlet potential energy surface. The present results may be helpful in understanding the mechanism of the title reaction and further experimental investigation of the reaction.

Keywords:   Theoretical chemistry, Density functional calculations, Gas phase reactions, Potential energy surfaces, Acetone, Lanthanum

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 676-680

Single-step synthesis and structural study of phosphate modified titania
through seeding method

K Joseph Antony Raj, T Elangovan & B Viswanathan*

National Centre for Catalysis Research, Indian Institute of Technology Madras, Chennai 600 036, India

Email: bvnathan@iitm.ac.in

Received 3 December 2011; revised and accepted 3 March 2012

A single-step organic-free process has been evolved to prepare phosphate-modified titania, a nanomaterial, from titanium oxysulphate solution. The adsorption of phosphate ions from aqueous solution onto titania has been studied by XRD, XPS, and DRIFT which show strong adsorption of phosphate, as Ti-O-P on the surface of titania. An increase in crystallinity and decrease in surface area are observed with calcination temperature. XPS results reveal a pentavalent oxidation state for P and the substitution of P for oxygen. The phosphate modified titania displays good thermal stability, an essential property required for the application as catalyst and active support.

Keywords: Catalyst, Mesoporous phosphated titania, Phosphated titania, Titania, Titanium oxysulphate, Seeding method

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 681-689

Kinetic and mechanistic studies of oxidation of glycine and valine by
N-bromosuccinimide using chloro complex of Rh(III) in its
nano-concentration range as homogeneous catalyst

Ashok Kumar Singh*, Rajesh Kumar Singh, Jaya Srivastava, Shahla Rahmani & Sarita Yadav

Department of Chemistry, University of Allahabad, Allahabad 211 002, Uttar Pradesh, India

Email: ashokeks@rediffmail.com/ ashok_au2@yahoo.co.in

Received 26 July 2011; revised and accepted: 18 April 2012

Kinetics of oxidation of glycine (gly) and valine (val) by N-bromosuccinimide (NBS) using chloro complex of Rh(III) in its nano-concentration range as homogeneous catalyst have been investigated at 35 oC . The reaction shows first order kinetics with respect to NBS and Rh(III) in the oxidation of both the amino acids. The first order kinetics with respect to amino acid obtained at its lower concentration changes to zero order at its higher concentration. Inverse fractional order with respect to [H+] was obtained in Rh(III)-catalysed oxidation of gly and val. Variation in [Hg(II)], [NHS], [Cl-], ionic strength and dielectric constant of the medium has no effect on the rate of oxidation of both the amino acids. NBS itself and [RhCl5(H2O)]2- have been postulated as the reactive species of NBS and Rh(III) chloride in acidic medium, respectively. Various activation parameters have been calculated with the pseudo-first-order rate constant values observed at four different temperatures. The main oxidation products of the reactions have been identified as formaldehyde and ammonia in the case of gly and isobutaldehyde and ammonia in the case of val. The proposed reaction mechanism is well supported by kinetic data, spectrophotometric evidence and positive entropy of activation.

Keywords: Kinetics, Reaction mechanisms, Rhodium, Oxidation, Amino acids

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 690-694

On atom-bond connectivity index and its chemical applicability

Ivan Gutman, Jelena Tošović, Slavko Radenković & Svetlana Marković

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

Email: gutman@kg.ac.rs

Received 1 December 2011; revised and accepted 17 April 2012

A critical re-examination confirms that the atom-bond connectivity index (ABC) is well reproducing the heats of formation of alkanes (DH°f). Moreover, the simple empirical formula DH°f  = – (a+b·ABC), with a = 65.98, b = 20.37, reproduces the heats of formation with an accuracy comparable to that of high-level ab initio and DFT (MP2, B3LYP) quantum chemical calculations.

Keywords: Theoretical chemistry, Atom-bond connectivity index, Heat of formation, Alkanes

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 695-698

A global model to predict density of non-aqueous binary solvent mixtures at various temperatures

Abolghasem Jouybana,*, Seyed Hamed Maljaeib,Maryam Khoubnasabjafaric & Anahita Fathi-Azarbayjanid

aDrug Applied Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz 51664, Iran

Email: ajouyban@hotmail.com

bLiver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz 51664, Iran

cTuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran

dDepartment of Pharmacology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran

Received 13 December 2011; revised and accepted 30 March 2012

The combined form of the Jouyban-Acree model and the calculated Abraham solute parameters has been used to predict the density of binary solvent mixtures at various temperatures. The proposed model has been trained using 290 binary solvent systems at different temperatures (278.15 to 353.15 K) and concentration ranges. The results are discussed in terms of mean relative deviations (MRDs) between computed and experimental densities as an accuracy criterion. The MRD of the proposed model is 1.2 ± 1.9 %, indicating that the proposed model, together with the calculated Abraham parameters, is accureate to reproduce the concentration and temperature dependence of density values of binary solvent mixtures.

Keywords: Theoretical chemistry, Density, Jouyban-Acree model, Binary solvent mixtures, Abraham solute parameters.

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 699-703

 

In situ bismuth film modified carbon fiber microelectrode for nanomolar detection of cadmium and lead

S Anandhakumar, J Mathiyarasu* & K L N Phani

Nanoscale Electrocatalysis and Sensor Research Group, Electrodics and Electrocatalysis Division, CSIR-Central Electrochemical Research Institute,

Karaikudi 630 006, Tamilnadu, India

Email: almathi@cecri.res.in

Received 11 January 2012; revised and accepted 16 April 2012

In situ bismuth film modified carbon fiber microelectrode is reported for sensitive detection of Cd(II) and Pb(II) in 0.1 M acetate buffer solution of pH 4.5. As compared to the unmodified electrode, in situ bismuth modification improves the detection limit at nanomolar level for individual as well as simultaneous detection of Cd(II) and Pb(II). Electroanalysis carried out using square wave anodic stripping voltammetry shows linear response over the 50-500 nM range. The minimum detection limits are not affected for the individual and simultaneous metal detection. Using the standard addition method, cadmium and lead have been detected in tap water samples successfully.

Keywords:   Bismuth, Microelectrodes, Heavy metals, Cadmium, Lead, Square wave anodic stripping voltammetry

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp. 704-707

 

Study of sulphonic acid functionalization of Vulcan XC-72 carbon black support of Pt/Vulcan XC-72 catalyst for methanol electrooxidation

Sundar Chandravathanama, B Kavithaa, Balasubramanian Viswanathanb,* & Y Yesu Thangama

aDepartment of Chemistry, Jayaraj Annapackiam College for Women (Autonomous),
Periyakulam 625 601, Tamil Nadu, India

bNational Centre for Catalysis Research, Indian Institute of Technology Madras, Chennai 600 036, Tamil Nadu, India

Email: bvnathan@iitm.ac.in

Received 8 November 2011; revised and accepted 24 April 2012

Sulphonic acid groups have been grafted onto the surface of Vulcan XC-72 carbon of the Pt/Vulcan XC-72 catalyst to improve platinum utilization in methanol electrooxidation studies. The sulphonic acid modification has been carried out by reacting the Pt/Vulcan XC-72 catalyst with formaldehyde and sodium sulfite. The resultant sulphonated catalysts are characterized by X-ray diffraction, Fourier transform infrared spectroscopy and cyclic voltammetry. FT-IR spectra confirm the incorporation of the sulphonic acid group on the carbon black support of the catalyst. XRD shows better dispersion of the Pt nanoparticles upon sulphonic acid modification. The electrochemical measurement using cyclic voltammetry shows enhanced activity for methanol electrooxidation for the sulphonic acid modified catalyst as compared to the unmodified one.

Keywords: Catalysts, Sulphonated catalysts, Electrooxidation, Cyclic voltammetry, Methanol oxidation,
Sulphonic acid, Platinum

 

 

Indian Journal of Chemistry

Vol. 51A, May 2012, pp 708-713

 

Hydrothermal synthesis and characterization of lanthanide oxalates:
In situ oxalate formation from tartaric acid in presence of KI

Muhammad Athar* & Ashfaq Mahmood Qureshi

Department of Chemistry, Bahauddin Zakariya University, Multan, Pakistan

Email: athar.qr@gmail.com

and

Guanghua Li, Zhan Shi & Shouhua Feng

State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University,
Changchun,
PR China

Email: shfeng@mail.jlu.edu.cn

Received 21 December 2011; revised and accepted 18 April 2012

Two new three-dimensional lanthanide oxalates [Pr2(C2O4)3(H2O)4]·2H2O (1) and [Nd2(C2O4)3(H2O)4]·2H2O (2) and a two-dimensional oxalate [Pr2(C2O4)3(H2O)6]·3H2O (3) have been prepared by hydrothermal process and characterized by single crystal X-ray analysis. Compound (1) crystallizes in monoclinic crystal system with P21/c space group whereas (2) crystallizes in triclinic crystal system with
Pī space group. Although Pr and Nd are twin lanthanides, they have produced different crystal structures under the same reaction conditions. Compound (3) is produced by the in situ hydrothermal degradation of tartaric acid to oxalate ions in presence of KI. In this reaction, the iodide anion instead of metal cation, acts as the reducing agent during the degradation of tartaric acid to oxalate. Thermogravimetric, elemental analysis and
IR studies have also been carried out for these compounds.

Keywords: Hydrothermal synthesis, Lanthanides, Oxalates, Degradation, Tartaric acid, Potassium iodide