Indian Journal of Chemistry

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

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

http://www.niscair.res.in; http://nopr.niscair.res.in 

Total visitors: 7608 since 29-7-2011

 

 

 

VOLUME 50A

NUMBER 8

AUGUST 2011

CONTENTS

 

1017

 

Lanthanum and zinc incorporated hydrotalcites as solid base catalysts for biodiesel and biolubricants production

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R Rahul, Jitendra K Satyarthi & D Srinivas*

 

 

 

Calcined hydrotalcites doped with varying amounts of La3+ and Zn2+ ions exhibit high catalytic activity for biodiesel and biolubricants production. Catalytic activity varies with the basicity of the catalysts.

 

 

 

fig 5

 

1026

 

Electrochemical sensor for the simultaneous voltammetric determination of adenosine and adenine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rajendra N Goyal*, Sunita Bishnoi & Rakesh K Singh

 

 

 

Sensor based on bare and single walled carbon nanotubes modified edge plane pyrolytic graphite electrode is reported for the simultaneous determination of adenine and adenosine in phosphate buffer of pH 7.2. The modified electrode exhibits enhanced electrocatalytic properties towards adenosine and adenine with a peak potential of ~ 1190 mV and ~ 856 mV, respectively.

 

IC 3172_GA

 

 

 

1035

 

Reactivity of tricine in the presence of Cu(ClO4)2.6H2O and 2,2'-bipyridine: Synthesis, characterization and magnetic property of the complexes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Vinod Kumar Yadav, Niraj Kumari & Lallan Mishra*

 

 

 

Tricine  in  the presence of  Cu(ClO4)2.6H2O and  2,2'-bipyridine in alkaline medium gives mononuclear, dinuclear and hexanuclear Cu(II) complexes.

 

Graphical abstract_Corr

 

 

1043

 

Organized media as redox catalysts on the reaction rate of  CoIII-FeII redox couple

 

 

 

 

 

 

 

 

 

 

 

 

Mousumi Mukherjee & Ambikesh Mahapatra*

 

 

 

The presence of various organized media (micelles/ reverse micelles/ Cu nanoparticles/ different salts or urea in presence of surfactant) affects the reaction rate of the CoIII–FeII redox couple. Coulombic and non-coulombic forces bear a profound influence on the encounter probability.

 

[CoIII(NH3)5(Cl)]2+ + [FeII(H2O)6]2+

 

                                               

 

 

[CoII(H2O)6]2+ + [FeIII(H2O)6]3+ + 5NH4+ + HCl

 

Notes

 

1050

 

Surface acidic properties of sulphated Fe2O3-TiO2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

K Joseph Antony Raj, M G Prakash, R Shanmugam,
K R Krishnamurthy & B Viswanathan
*

 

 

 

The possible structure for pyridine adsorbed sulphated Fe2O3-TiO2 has been investigated employing DFT and DRIFT spectra.

 

 

Description: C:\Users\shanmugam\Desktop\New folder (2)\Untitled-6 n.jpg

 

1056

 

Enhanced activity of Au catalysts from extra-high surface area CeO2 for CO oxidation

 

 

 

 

 

 

 

 

 

 

 

 

 

Ling-Yun Jin, Cun-Xia Guo, Yue-Juan Wang,
Ji-Qing Lu & Meng-Fei Luo
*

 

 

 

CO adsorbed on Au particles reacts with active oxygen species provided by oxygen vacancies in AuxCe1-xO2-d solid solutions.

 

 

IC 3116_GA

 

 

 

 

 

1061

 

BaCrO4 assisted visible light induced advanced oxidation process for mineralizing Azur B

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Brijesh Pare*, Vijendra Singh & S B Jonnalagadda

 

 

 

The photocatalyst BaCrO4 has been utilized to photocatalytically degrade Azur B in presence of visible light. Electron acceptors like NaCl and Na2CO3 retard the rate of photocatalytic degradation, whereas oxidants such as H2O2 and K2S2O8 increase the degradation rate. The degradation efficiency was found to be substantially high at around neutral pH. Complete degradation of the dye has been confirmed using UV spectrum analysis.

 

 

 

01

 

 

Authors for correspondence are indicated by (*)

 

 

 

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1017-1025

 

Lanthanum and zinc incorporated hydrotalcites as solid base catalysts for
biodiesel and biolubricants production

 

R Rahul, Jitendra K Satyarthi & D Srinivas*

Catalysis Division, National Chemical Laboratory, Pune 411 008, India

Email: d.srinivas@ncl.res.in

Received 24 June 2011; revised and accepted 15 July 2011

Mg-Al hydrotalcites doped with varying amounts of lanthanum and zinc ions (10 – 30 mol %) have been prepared by
co-precipitation method and used, after calcination at 873 K, as solid base catalysts for transesterification of soybean oil with methanol (producing biodiesel) and n-octanol (producing biolubricants). The catalyst with 20 mol % of lanthanum shows the highest transesterification activity (soybean oil conversion = 100 % and biodiesel yield = 95 %) at 423 K in
 4 h. Catalytic activity varies in proportion with the basicity of the catalysts.

Keywords:   Catalysis, Solid base catalysts, Hydrotalcites, Doped hydrotalcites, Lanthanum, Zinc, Transesterification, Vegetable oils, Biodiesel, Biolubricants

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1026-1034

 

Electrochemical sensor for the simultaneous voltammetric determination of adenosine and adenine

Rajendra N Goyal*, Sunita Bishnoi & Rakesh K Singh

Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667, India

Email: rngcyfcy@iitr.ernet.in

Received 9 June 2011; revised and accepted 15 July 2011

Electrochemical method based on voltammetry using bare and single walled carbon nanotubes (SWNT) modified edge plane pyrolytic graphite electrode (EPPGE) is proposed for the simultaneous determination of adenosine and adenine in phosphate buffer medium of pH 7.2. The oxidation peak current of both the analytes increases significantly along with the negative shift of peak potentials using SWNT/EPPGE as compared to bare EPPGE. The modified electrode exhibits enhanced electrocatalytic properties towards adenosine and adenine with a peak potential of ~ 1190 mV and ~ 856 mV, respectively. Oxidation of both the compounds occurs in a pH-dependent process, and the electrode reaction follows diffusion controlled pathway. The concentration versus peak current plots are linear for both the analytes. The detection limit (3σ/slope) observed for adenine and adenosine are 1.1 and 2.9 µM, respectively. The developed protocol has been implemented for the simultaneous determination of adenosine and adenine in human urine samples of normal subjects with good results.

Keywords: Electrochemistry, Electroxidation, Nanotubes, Carbon nanotubes, Single walled carbon nanotubes, Adenine, Adenosine, Square wave voltammetry

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1035-1042

 

Reactivity of tricine in the presence of Cu(ClO4)2.6H2O and 2,2'-bipyridine: Synthesis, characterization and magnetic property of the complexes

Vinod Kumar Yadav, Niraj Kumari & Lallan Mishra*

Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221 005, India

Email: lmishrabhu@yahoo.co.in

Received 1 June 2011, revised and accepted 14 July 2011

Three complexes, [Cu(bpy)(μ-OH)]2·2ClO4 (1) [Cu(H4TRI)(bpy)]ClO4 (2) and [Cu3(bpy)5(μ-O)(NO3)]2·6ClO4 (3) {H4TRI= tricine, bpy= 2,2'-bipyridine} have been synthesized and characterized using their IR, UV-vis and ESR spectroscopic data , elemental analysis and single crystal X-ray diffraction studies. The π-π interaction along the a-axis in complex (1) provides a channel- type structure while similar interaction in complex (2) generates a channel with floating ClO4- anions. Complex (3) comprises a pair of Cu(II) centers connected via (μ2-O) oxo bridges. These are further linked to Cu3 and Cu3#1 centers via oxygen atoms of the nitrate anion. The assembled structure of this complex along the c- axis displays a zig-zag chain formation. The variable temperature magnetic measurement of a representative complex (3), [Cu3(bpy)5(μ-O)(NO3)]2·6ClO4, shows that two of the Cu(II) centers couple ferromagnetically.

Keywords: Coordination chemistry, Polynuclear complexes, Tricine, Copper, Ferromagnetic interactions

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1043-1049

 

Organized media as redox catalysts on the reaction rate of
CoIII-FeII redox couple

Mousumi Mukherjee & Ambikesh Mahapatra*

Department of Chemistry, Jadavpur University, Kolkata 700 032, India

Email: ambikesh_ju@yahoo.com/amahapatra@chemistry.jdvu.ac.in

Received 1 March 2011; revised and accepted 14 July 2011

Micelles catalyze the [Co(NH3)5Cl](NO3)2 - Mohr’s salt redox reaction due to the binding of the substrates onto the micellar surface by non-coulombic and coulombic interactions. This binding increases the encounter probability, leading to a substantially accelerated reaction. The kinetic studies of the same redox reaction have also been carried out in the water pools of non-ionic reverse micelles of Triton X-100/1-butanol in n-heptane. The findings indicate that probably substrate solubilization sites in micelles and reverse micelles are the interfacial and Stern regions. The reaction rates decrease with the water-to-surfactant mole ratio. The correct selection of surfactant for micelle, size of reverse micellar water pool cavity, different additives and the catalyst connecting nanoparticles control the electron transfer reaction rate in solution. Copper-sol induced catalysis occurs due to the availability of a suitable surface which acts as a mediator for the electron-transfer reaction between [Co(NH3)5Cl](NO3)2 and Mohr’s salt.

Keywords: Solution chemistry, Kinetics, Electron transfer, Surfactants, Micelles, Reverse micelles, Organized media, Cobalt-Iron redox reaction

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1050-1055

 

Surface acidic properties of sulphated Fe2O3-TiO2

K Joseph Antony Raj, M G Prakash, R Shanmugam,
K R Krishnamurthy & B Viswanathan*

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

Email: bvnathan@iitm.ac.in

Received 5 May 2011; revised and accepted 11 July 2011

Mixed iron and titanium oxides with varying quantities of sulphate species have been prepared by sulphation of ilmenite followed by calcination. A combined approach involving DFT and DRIFT spectroscopy has been adopted to determine the appropriate structure for adsorption of pyridine on sulphated Fe2O3-TiO2 (SFT). The DRIFT spectra obtained for pyridine adsorbed SFT samples show equal number of Brønsted and Lewis acid sites. The TG-DTG analysis reveals the greater affinity for water and hydroxyl groups on SFT. Evaluation of IR frequencies for various structures based on DFT demonstrates that the adsorption of water/hydroxyl groups on S and/or Fe leads to the conversion of Lewis acid sites into Brønsted acid sites. Investigation of Mulliken charges for Fe, Ti, S and N for the pyridine adsorbed SFT structures demonstrates the preferable adsorption of pyridine on sulphur rather than on Fe.

Keywords: Catalysis, Acidity, Density functional calculations, Sulphated iron oxide, Iron oxide, Titania

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1056-1060

 

Enhanced activity of Au catalysts from extra-high surface area CeO2
for CO oxidation

Ling-Yun Jin, Cun-Xia Guo, Yue-Juan Wang, Ji-Qing Lu & Meng-Fei Luo*

Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, PR China

Email: mengfeiluo@zjnu.cn

Received 30 March 2011; revised and accepted 15 July 2011

A series of Au/CeO2 catalysts has been prepared with CeO2 of varying surface areas and tested for low-temperature CO oxidation. With a higher surface area support, the Au/CeO2 catalysts show a higher catalytic activity for CO oxidation (0.175 molCO gAu-1 h-1 at 0 °C). Higher oxygen vacancies provided by the formation of solid solution of AuxCe1-xO2-δ and higher CO chemisorption sites related to Au species are responsible for the enhanced activity.

Keywords: Catalysts, Solid catalysts, Oxidation, CO oxidation, Solid solutions, Oxygen vacancies, Gold, Ceria

 

 

Indian Journal of Chemistry

Vol. 50A, August 2011, pp. 1061-1065

 

BaCrO4 assisted visible light induced advanced oxidation process for
mineralizing Azur B

Brijesh Parea, *, Vijendra Singha & S B Jonnalagaddab

aLaboratory of Photocatalysis, Madhav Science P G College, Ujjain 456 010, India

bDepartment of Chemistry, University of KwaZulu- Natal, Westville, Durban, South Africa

Email: brijeshpare2009@hotmail.com/

   vijendrasingh2010@hotmail.com

Received 27 October 2010; re-revised and accepted 26 June 2011

The photocatalyst BaCrO4 has been utilized to photocatalytically degrade Azur B in presence of visible light. The disappearance of the dye has been monitored spectrophotometrically, followed pseudo-first order kinetics, according to the Langmuir–Hinshelwood model. The total degradation of dye was tested by determining the chemical oxygen demand. To optimize the reaction condition, the effects of various parameters like amount of semiconductor, pH, light intensity, dye concentration, oxidants such as H2O2 and K2S2O8, electron acceptors like NaCl and Na2CO3, on the rate of photodegradation have been investigated. Both NaCl and Na2CO3 are found to retard the rate of photocatalytic degradation, whereas increase in the initial concentration of both H2O2 and K2S2O8, increases the degradation rate. The degradation efficiency was found to be the substantially high at around neutral pH values. The complete degradation of the dye has been confirmed using UV spectrum analysis. A pertinent mechanism for the photocatalytic degradation has also been proposed.

Keywords: Photochemistry, Photocatalysis, Degradation, Advanced oxidation process