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)

 

 

 

 

VOLUME 52A

NUMBER 7

JULY 2013

 

CONTENTS

 

 

835

 

DNA cleavage activity and cytotoxicity of mononuclear and trinuclear Cu(II) complexes containing 1H-pyrazole-3,5-dicarboxylic acid as ligand

 

 

 

 

 

 

 

 

 

 

 

Ashish Kumar Srivastava, Niraj Kumari ,
Rais Ahmad Khan, Richa Rai, Geeta Rai,
Sartaj Tabassum & Lallan Mishra
*

 

 

 

Mononuclear and trinuclear Cu(II) complexes with 1H-pyrazole-3,5-dicarboxylic acid  and bpy cleave supercoiled plasmid DNA into nicked circular DNA, while the  trinuclear Cu(II) complex  also shows significant cytotoxicity against CaSki, HL-60 and THP-1 cell lines.

 

 

 

 

 

845

 

Synthesis, spectral characterization and DNA interactions of copper(II) and nickel(II) complexes with unsymmetrical Schiff base ligands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M Pragathi  & K Hussain Reddy*

 

 

 

Mononuclear copper(II) and nickel(II) complexes with unsymmetrical Schiff base ligands obtained from equimolar condensation of salicylaldehyde/2-hydroxyacetophenone, acetylacetone and 1,2-diaminoethane/1,3-diaminopropane are synthesized and characterized. These complexes show good binding affinity towards DNA and also significant oxidative cleavage activity towards double strand pBR 322 plasmid DNA.

 

 

 

 

854

 

Kinetics of iodate oxidation of lactose in presence of [IrCl3(H2O)2OH]- as homogeneous catalyst

 

 

 

 

 

 

 

 

 

 

 

 

Ashok Kumar Singh*, Rashmi Srivastava,
Shahla Rahmani & Priyanka Singh

 

 

 

Mechanistic studies have been carried out on the oxidation of lactose by potassium iodate in the presence of Ir(III) chloride as catalyst at 40 °C. The most probable mechanism shows the formation of the most reactive activated complex by interaction of a charged complex species and a reactive species IO3-.

 

 

 

Notes

 

863

 

Synthesis, structure and catalytic aspects of the palladium(II) complex [PdLCl] (where LH = 2-formyl-4-methyl-6-N-ethylpiperidineiminomethylphenol)

 

 

 

 

 

 

Debasis Das *, Pali Maiti, Avik Kr Bagdi,
Totan Ghosh, Tanmay Chattopadhay,
Sudhanshu Das, Alakananda Hajra,
Adinath Majee  & Ennio Zangrando

 

 

 

A Pd(II) Schiff base complex has been exploited for the first time as an efficient catalyst  for coupling of acyl chlorides with terminal alkynes under copper- and solvent-free conditions at room temperature to synthesize ynones.

 

 

 

 

 

 

 

868

 

Preparation of Pt/CeO2-ZrO2/carbon nanotubes hybrid catalysts for methanol electrooxidation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Jinxue Guo, Yanfang Sun, Xiao Zhang*,
Hongtao Zhu & Lin Tang

 

 

 

Pt/CeO2-ZrO2/MWCNT catalysts synthesized by an ultrasonic method exhibit good catalytic activity and long term stability for methanol oxidation, which is attributed to the high OSC and good catalytic activity for CO oxidation of CeO2-ZrO2.

 

 

 

 

 

873

 

Composition of n-dedocyl polyglucoside based middle phase microemulsions in surfactant-enhanced aquifer remediation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Xiaodeng Yang*, Tianduo Li, Lei Shi, Junying Li & Jinling Chai

 

 

 

 

The e-b fishlike phase diagram for the APG/n-butanol/NAPLs/water quaternary system shows that the plot of volume fraction of the middle phase at the mid-point region versus β is linear.

 

 

 

 

879

 

Effect of surfactants on polyvinyl alcohol-borax hydrogel: Rheology and thermal aspects

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Naorem Shubhaschandra Singh

 

 

 

The addition of sodium dodecyl sulphate well below the critical micelle concentration facilitates cross-linked networks in polyvinyl alcohol-borax hydrogel, which shows Maxwellian fluid behavior to some extent. Addition of TX-100 even below the CMC or SDS beyond CMC, on the other hand, destabilizes the cross-linked gel network.

 

G′ (Pa)

 

 

Authors for correspondence are indicated by (*)

 

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 835-844

 

 

DNA cleavage activity and cytotoxicity of mononuclear and trinuclear Cu(II) complexes containing 1H-pyrazole-3,5-dicarboxylic acid as ligand

Ashish Kumar Srivastavaa, Niraj Kumari a, Rais Ahmad Khanb, Richa Raic, Geeta Raic,
Sartaj Tabassumb & Lallan Mishraa, *

aDepartment of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi, India

Email: lmishrabhu@yahoo.co.in

bDepartment of Chemistry, Aligarh Muslim University, Aligarh, India

cMolecular and Human Genetics, Banaras Hindu University, Varanasi, India

Received 18 February 2013; re-revised and accepted 12 June 2013

UV-vis titrations of complexes [Cu(H2pdc)2(H2O)2] (1) and [Cu3(pdc)2(bpy)2(H2O)4] (2) (H3pdc=1H-pyrazole-
3,5-dicarboxylic acid, bpy=2,2' bipyridine)
with calf thymus DNA demonstrate their moderate binding with DNA. Fluorescence titrations show significant displacement of ethidium bromide bound to DNA by the complexes. Agarose gel electrophoretic mobility assay indicates that the complexes are able to cause concentration-dependent nicking of supercoiled DNA under physiological conditions. Ligation experiments with T4 DNA ligase enzyme show that the nicked DNA cleavage products generated by complexes (1) and (2) is religated to a large extent in the presence of T4 ligase enzyme. Complex (2) shows potential cytotoxicity against CaSki cervical cancer, HL-60 leukemic cell lines and THP-1 human monocytic cell lines with IC50 value of 1.5 µM, 2.5 µM and 10 µM respectively. A redox inactive Zn(II) complex of type [Zn(H2pdc)2(H2O)2]· H2O (3) was also synthesized and characterized but owing to its poor solubility, further studies could not be carried out.

Keywords: Coordination chemistry, Bioinorganic chemistry, Cytotoxic activity, DNA cleavage, DNA binding,     Chemical nuclease activity, Copper

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 845-853

 

Synthesis, spectral characterization and DNA interactions of copper(II) and nickel(II) complexes with unsymmetrical Schiff base ligands

M Pragathia & K Hussain Reddyb, *

aDepartment of Chemistry, Government Degree College (Men), Anantapur 515 001, Andhra Pradesh, India

Email: khussainreddy@yahoo.co.in

bDepartment of Chemistry, Sri Krishnadevaraya University, Anantapur 515 003, Andhra Pradesh, India

Received 18 July 2012; revised and accepted 18 June 2013

Salen-type of Schiff base ligands incorporating two different carbonyl moieties, viz., acetylacetone and salicylaldehyde and a diamine (1,2-ethylenediamine and 1,3-propylenediamine) as backbone have been synthesized via stepwise approach and characterized. Mononuclear complexes of copper(II) and nickel(II) have been synthesized with these ligands and characterized based on molar conductance, magnetic moments, electronic, IR and ESR spectral data. The copper complex undergoes quasi-reversible one electron reduction (CuII/CuI) in the potential range 0.357 to 0.410 V while the nickel complexes show two active response in the potential range -1.151 to -1.288 and
-1.371 to -1.680, assigned to NiII/NiIII oxidation couple and NiII/NiI reduction couple respectively against Ag/AgCl reference electrode. Copper(II) complexes bind with CT-DNA very strongly when compared with nickel(II) complexes. Copper(II) complexes exhibit DNA cleavage activity even in the absence of an oxidant, but this activity becomes more pronounced in the presence of an oxidant. The nuclease activity of copper(II) complexes is found to be more when compared with that of nickel(II) complexes both in the absence and in the presence of an oxidant.

Keywords: Coordination chemistry, Schiff bases, DNA binding, DNA cleavage, Nuclease activity, Copper, Nickel

 

 

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 854-862

 

 

Kinetics of iodate oxidation of lactose in presence of [IrCl3(H2O)2OH]-
as homogeneous catalyst

Ashok Kumar Singh*, Rashmi Srivastava, Shahla Rahmani & Priyanka Singh

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

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

Received 22 August 2012; revised and accepted 19 June 2013

The kinetics and mechanism of oxidation of lactose by potassium iodate in the presence of Ir(III) chloride as homogeneous catalyst in aqueous alkaline medium has been investigated. The reaction is found to be first order with respect to sugar, iodate and hydroxyl ions at their low concentrations (sugar from 1.00×10-2 to 3.00×10-2 M , iodate from 2.50×10-4 to 15.00×10-4 M and hydroxyl ions from 8.00×10-2 to 24.00×10-2 M) and zero order with respect to sugar, iodate and hydroxyl ions at their high concentrations (sugar from 3.50×10-2 to 10.00×10-2 M, iodate from 17.50×10-4 to 25.00×10-4 M and hydroxyl ions from 32.00×10-2 to 80.00×10-2 M). Rate of oxidation is directly proportional to [Ir(III)] throughout its variation. Ionic strength of the medium and [Cl] have no effect on the rate of oxidation. From the values of observed  rate constants at four different temperatures, the activation parameters have been calculated. Lyxonic acid, arabinonic acid and formic acid have been identified as the main oxidation products of the reaction. The results are in accord with the proposed mechanism in which the most reactive activated complex, [C6H11O9I.IrCl3(H2O)2]2- in the rate determining step, decomposes into an intermediate, which finally forms the products through fast steps with regeneration of the effective species of catalyst.

 

Keywords: Kinetics, Reaction mechanisms, Oxidations, Copper-bipyridyl complex, Ruthenium, Lactose

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 863-867

 

 

Synthesis, structure and catalytic aspects of the palladium(II) complex [PdLCl] (where LH = 2-formyl-4-methyl-6-N- ethylpiperidineiminomethylphenol)

Debasis Dasa, *, Pali Maitia, †, Avik Kr Bagdib, Totan Ghosha,
Tanmay Chattopadhayc, Sudhanshu Dasa, Alakananda Hajrab,
Adinath Majeeb & Ennio Zangrandod

aDepartment of Chemistry, University of Calcutta, 92, APC Road, Kolkata 700 009, India

Email: dasdebasis2001@yahoo.com.

bDepartment of Chemistry, Visva-Bharati University,  Santiniketan 731 235, India

cDepartment of Chemistry, Panchakot Mahavidyalay, Sarbari, Purulia, India

dDipartimento di Scienze Chimiche e Farmaceutiche, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy

Received 11 June 2012; revised and accepted 17 June 2013

A square planar neutral Pd(II) complex, [PdLCl], of the Schiff base ligand, 2-formyl-4-methyl-6-N-ethylpiperidineimino methylphenol, has been synthesized and structurally characterized. The complex has been employed as catalyst precursor for the synthesis of ynones by coupling acyl chlorides with terminal alkynes under copper- and solvent-free conditions at room temperature.

 

Keywords: Coordination Chemistry, Ynones, Coupling reaction, Palladium, Schiff bases

 

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 868-872

 

Preparation of Pt/CeO2-ZrO2/carbon nanotubes hybrid catalysts
for methanol electrooxidation

Jinxue Guo, Yanfang Sun, Xiao Zhang*, Hongtao Zhu & Lin Tang

State Key Laboratory Base of Eco-chemical Engineering, College of Chemistry and Molecular Engineering,
Qingdao University of Science and Technology, Qingdao 266042, PR China

Email: zhx1213@126.com

Received 15 April 2013; accepted 20 June 2013

Pt/CeO2-ZrO2/multi-walled carbon nanotubes composites have been synthesized for the application of catalyst in direct methanol fuel cells. The introduction of CeO2-ZrO2, which has high surface area and oxygen storage capacity, can eliminate the toxic gases at low temperature. Electrocatalytic activity and stability of Pt/CeO2-ZrO2/MWCNT catalysts for methanol oxidation have been investigated with cyclic voltammetric and chronoamperometric techniques. Electrochemical measurements demonstrate that the Pt/CeO2-ZrO2/MWCNT catalysts exhibit superior electrocatalytic activities as compared with Pt/CeO2/MWCNT and Pt/MWCNT catalysts. The peak current density of Pt/CeO2-ZrO2/MWCNT catalysts for methanol electrooxidation is 3.9 times as high as that of Pt/MWCNT catalysts. The outstanding performance is likely to be due to the co-catalytic effect of CeO2-ZrO2 and the deposition manner of Pt nanoparticles.

Keywords: Catalysts, Electrocatalysts, Electrooxidation, Fuel cells, Methanol electrooxidation,
Electrochemical deposition, Platinum, Ceria, Zirconia, Carbon nanotubes

 

 

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 873-878

 

Composition of n-dedocyl polyglucoside based middle phase microemulsions in surfactant-enhanced aquifer remediation

Xiaodeng Yanga, *, Tianduo Lia, Lei Shia, Junying Lia & Jinling Chaib

aShandong Provincial Key Laboratory of Fine Chemicals, Shandong Polytechnic University,
Ji’nan, 250353, PR China

Email: yangxiaodeng@spu.edu.cn

bDepartment of Chemistry, Shandong Normal University,
Ji’nan, 250014, PR China

Received 12 September 2012; revised and accepted 20 June 2013

The composition and solubilization power of the middle phase microemulsion formed by n-dodecyl polyglucoside (APG)/n-butanol/water/non-aqueous phase liquids (NAPLs) quaternary system have been studied. The hydrophile-lipophile balanced (HLB) plane equation for the quaternary system has been deduced. Some physicochemical parameter, such as the mass fraction of n-butanol in the HLB interfacial layer, the coordinates of the start and end points of the middle phase microemulsion, the mass fractions of APG and n-butanol in the total system, and the solubilities of APG and n-butanol in oil phase are calculated. The washing liquids prepared according to the physicochemical parameters of the n-dodecyl polyglucoside based middle-phase microemulsion have been used to wash the NAPLs adsorbed on soil. The results indicate that the APG based middle phase microemulsion is suitable in surfactant-enhanced aquifer remediation.

Keywords: Microemulsions, Polyglucoside  microemulsions, Middle phase microemulsions, Solubilization power, Surfactant enhanced aquifer remediation

Indian Journal of Chemistry

Vol. 52A, July 2013, pp. 879-883

 

 

Effect of surfactants on polyvinyl alcohol-borax hydrogel: Rheology and
thermal aspects

Naorem Shubhaschandra Singh

Department of Chemistry Churachandpur Govt College, Churachandpur 795 128, Manipur, India

Email: shubhasnaorem@yahoo.com

Received 10 July 2012; revised and accepted 10 June 2013

Addition of the surfactant, sodium dodecyl sulphate well below the critical micelle concentration facilitates cross-linked networks in the polyvinyl alcohol-borax hydrogel, while at a concentration higher than the CMC, surfactant micelles start destabilizing the cross-linking in the gel network. The PVA-borax hydrogel shows an increased elastic behavior, in particular at lower SDS concentration and Maxwellian fluid behaviour at lower concentration of both SDS and TX-100. Inclusion of SDS in the hydrogel also significantly lowers the gel-sol transition temperature.

Keywords: Surfactants, Gel network, Crosslinking, PVA-borax hydrogels, Rheology, Swelling ratio, Sol-gel transition, Surfactants