Indian Journal of Chemistry

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

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VOLUME 48A

NUMBER 6

June 2009

CONTENTS

 

761

 

Interaction of Ni(II)-ethylenediamine/histamine with histidylglycine and investigation of their DNA cleavage abilities

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pulimamidi R Reddy*, Nomula Raju,

Kandibanda S Rao & Addla Shilpa

 

 

 

 

The interaction of Ni(II)-ethylenediamine/histamine with histidylglycine is investigated and their DNA cleavage abilities probed. The intrinsic binding constants for the bound
complexes, Ni(II)-en-his-gly:DNA and Ni(II)-hist-his-gly:DNA, have been determined to be 280 and 420 M-1 respectively.
Gel-electrophoresis experiments reveal that both complexes cleave supercoiled DNA (type-I) to the nicked-circular (type-II) form hydrolytically at physiological pH.

 

 

 

 

769

 

Synthesis and structural characterization of
bis(n-propylammonium) tetrasulfidometalates

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bikshandarkoil R Srinivasan*, Ashish R Naik, Christian Näther & Wolfgang Bensch

 

 

 

 

The synthesis and structural characterization of two tetrasulfidometalates stabilized by n-propylammonium cation, (CH3-CH2-CH2-NH3)2[MS4] (M = W; Mo), are described. Both the compounds are isostructural and crystallize in the centrosymmetric orthorhombic space group, Pnma. The structure consists of discrete, slightly distorted tetrahedral tetrasulfidometalate [MS4]2- anions of m symmetry, separated by two crystallographically independent n-propylammonium cations located on mirror planes.

 

 

 

 

 

775

 

Surface potential and polarity at the micelle–solution interface in AOT + water system

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Snigdha Chanda & Kochi Ismail*

 

 

 

 

Surface potential of sodium dioctylsulfosuccinate micelles
(a double chained anionic surfactant with special properties),
in aqueous medium near the critical micelle concentration has been computed by solving the Poisson-Boltzmann equation and is found to be −117 mV, while the effective dielectric constant at the water–AOT micelle interface is estimated to be ~ 54 ± 4. The polarity determined at the micellar interfaces shows dependence on the probe used.

 

 

 

781

 

Kinetic assessment of relative counterion penetration into cationic micelles: Effects of inert salt on the rate of piperidinolysis of phenyl salicylate in alkaline cationic micelles

 

 

 

 

 

 

 

 

 

M Niyaz Khan* & Emran Ismail

 

 

 

 

Pseudo-first order rate constants for piperidinolysis of ionized phenyl salicylate, obtained at 0.1 M piperidine, at constant concentration of CTABr micelles and varying
[NaOC6H4CO2Na], follow the empirical relationship:
kobs = (k0 + q KX/S[MX]) / (1 + KX/S[MX]), where q and KX/S are empirical constants, MX = NaOC6H4CO2Na and k0 = kobs at
[MX] = 0. The q and KX/S are explained in terms of pseudophase micellar model coupled with an empirical relationship:
KS = KS0 /(1 + KX/S[MX]), where KX/S is an empirical constant and KS and KS0 are CTABr micellar binding constants of PS- in the presence and absence of MX respectively.

 

 

Notes

 

788

 

Gas-phase catalytic synthesis of MTBE from MeOH and ButOH over various microporous H-zeolites

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Q Zhang, Q-H Xia*, X-H Lu, X-T Ma & K-X Su

 

 

 

 

Several H-zeolites such as HZSM-5, HY, Hb, H-13X, H-K10 and HA have been used to catalyze the gas-phase synthesis of
methyl tert-butyl ether from methanol and tert-butanol in a continuous fixed-bed reactor. The ascending sequence of Brönsted acidity is: H-K10 (0.86) < Hb (2.04) < H-13X (2.83) < HY (3.93) < HZSM-5 (5.22), which is appreciably different from the order of Lewis acidity: H-K10 (0.87) < HZSM-5 (1.15) < H-13X (1.75) < HY (4.94) < Hb (6.10).

 

 

 

 

793

 

Preparation of a novel monolithic catalyst
CuO-CeO2 and its catalytic property in VOC oxidation

 

 

 

 

 

 

Zhu-nian Jin * & Yu-peng Song

 

 

 

 

A novel monolithic CuO-CeO2 catalyst has been prepared and tested for catalytic combustion of volatile organic compounds as a model reaction. The catalyst exhibits high catalytic activity in ethyl acetate and CO oxidation. The interaction between CeO2 and CuO may be responsible for the catalytic activity.

 

 

 

797

 

Kinetics and mechanism of oxidation of formic and oxalic acids by bis(pyridine) silver permanganate

 

 

 

 

 

 

 

 

 

 

Jayshree Banerji, Laszlo Kotai & Kalyan K Banerji*

 

 

 

 

Kinetics and mechanism of oxidation of formic and oxalic acids by bis(pyridine) silver permanganate in aqueous acetic acid have been studied.  The main product of oxidation is carbon dioxide. The reaction is first order each with respect to permanganate and the reductant. The reaction is catalyzed by hydrogen ions. The oxidation of adeuterioformic acid exhibits a substantial primary kinetic isotope effect (kH/kD = 3.69 at 298 K).

 

 

801

 

Linear solvation energy relationship in the reaction between phenacyl bromide and N-methyl aniline

 

 

 

 

 

 

 

 

B Ramesh, D Vijaya Bharathi, B Kavitha &

P Manikyamba*

 

 

 

 

The reaction between phenacyl bromide and N-methyl aniline has been studied conductometrically in 17 different protic and aprotic solvents. The reaction is overall second order, being first order with respect to each reactant.  Correlation of the second order rate constants with different solvent parameters indicates that the solvation of the reactants and the transition state is due to
non-specific polarity of the solvent, hydrogen bond donor ability, solvent nucleophilicity and electrophilicity of the solvent. By statistical analysis, a linear solvation energy relationship is derived and the percentage contribution of each type of solvation is estimated.

 

 

806

 

Partial molar volumes of oxalic acid and its salts in water-rich binary aqueous mixtures of methanol

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M L Parmar* & M K Guleria

 

 

 

Partial molar volumes of oxalic acid and its salts, viz., ammonium oxalate, sodium oxalate and potassium oxalate, have been determined in different compositions of water-rich binary aqueous mixtures of methanol (3, 6, 9, 12, and 15 wt. % methanol) from solution density measurements at 298.15 K and in 3% (w/w) methanol + water at different temperatures.  The data have been analysed by using Masson equation and the obtained parameters have been interpreted in terms of ion-solvent and ion-ion interactions.

 

 

812

 

Simultaneous kinetic determination of paracetamol and caffeine using Cu(II)-neocuproine in presence of dodecyl sulfate by H-point standard addition method

 

 

 

 

 

 

 

 

 

H Tavallali* & M Sheikhaei

 

 

 

A simple, feasible and selective kinetic spectrophotometric method for simultaneous determination of paracetamol and caffeine using H-point standard addition method is described. The method is based on difference in the rate of oxidation of the compounds with Cu(II)-neocuproine system and formation of Cu(I)–neocuproine complex, which is monitored at 453 nm and at pH 5.0 in the presence of sodium dodecyl sulfate. Paracetamol and caffeine can be determined in the ranges of 1.5-7.0 and
0.1-3.0 μg ml-1 respectively.

 

 

 

 

 

Authors for correspondence are indicated by (*)

 

 

 

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 761-768

 

 

Interaction of Ni(II)-ethylenediamine/histamine with histidylglycine and investigation of their DNA cleavage abilities

 

Pulimamidi R Reddy*, Nomula Raju, Kandibanda S Rao & Addla Shilpa

Department of Chemistry, Osmania University, Hyderabad 500 007, India

Email: rabi_pr@rediffmail.com

Received 4 February 2009; revised and accepted 23 April 2009

The interaction of Ni(II)-ethylenediamine (en)/histamine(hist) with histidylglycine(his-gly) and their DNA cleavage abilities have been investigated. The stability constants for the Ni(II)-en-his-gly (1) and Ni(II)-hist-his-gly (2) complexes have been determined at 298.0 K and 0.10 M (KNO3) ionic strength. Both the 1:1:1 ternary complexes have been corroborated by species distribution curves and ESI-MS analysis. The complex geometries have been analyzed by UV-vis experiments and molecular mechanics simulations. The DNA binding abilities of these complexes have been established by UV-vis-absorption, thermal-denaturation and fluorescence spectroscopy. The intrinsic binding constants for the bound complexes, Ni(II)-en-his-gly:DNA and Ni(II)-hist-his-gly:DNA, have been determined to be 280 and 420 M-1 respectively. Gel-electrophoresis experiments reveal that 1 and 2 cleave supercoiled DNA (type-I) to the nicked-circular (type-II) form hydrolytically at physiological pH. A tentative mechanism is proposed for the cleavage.

Keywords: Bioinorganic chemistry, Solution chemistry, Stability constants, DNA binding, DNA cleavage, Nickel (II)

IPC Code: Int. Cl.8 C07F15/04

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 769-774

 

 

Synthesis and structural characterization of bis(n-propylammonium) tetrasulfidometalates

Bikshandarkoil R Srinivasana,*, Ashish R Naika, Christian Nätherb & Wolfgang Benschb

aDepartment of Chemistry, Goa University, Goa 403 206, India

Email: srini@unigoa.ac.in

bInstitut für Anorganische Chemie, Christian-Albrechts-Universität Kiel, Max-Eyth Straße 2, D-24118, Kiel, Germany

Received 26 March 2009; revised and accepted 15 May 2009

The reaction of (NH4)2[MS4] (M = W, Mo) with n-propylamine (CH3-CH2-CH2-NH2) results in the formation of bis(n-propylammonium) tetrasulfidometalates (CH3-CH2-CH2-NH3)2[MS4] (M = W (1); Mo (2)). Both compounds have been characterized by elemental analysis, IR, Raman and UV-vis spectra and crystal structures. Compounds (1) and (2) are isostructural and crystallize in the centrosymmetric orthorhombic space group, Pnma. The structure consists of discrete slightly distorted tetrahedral tetrasulfidometalate [MS4]2- anions of m symmetry, separated by two crystallographically independent n-propylammonium cations located on mirror planes. The carbon atoms of the organic cations are disordered. A comparative study of twelve tetrasulfidometalates crystallizing in the orthorhombic space group Pnma is presented.

Keywords:Coordination chemistry, Crystal structure, X-ray crystallography, Tetrasulfidometalates, Molybdenum, Tungsten

IPC Code: Int. Cl.8 C07F11/00

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 775-780

 

 

Surface potential and polarity at the micelle-solution interface
in AOT + water system

Snigdha Chanda & Kochi Ismail*

Department of Chemistry, North Eastern Hill University, NEHU Campus, Shillong 793 022, India

Email: kismail@nehu.ac.in; kinehu@hotmail.com

Received 17 February 2009; revised and accepted 18 May 2009

Surface potential of sodium dioctylsulfosuccinate (AOT) micelles (a double-chained anionic surfactant with special properties), in aqueous medium near the critical micelle concentration has been computed by solving the Poission-Boltzmann equation and is found to be −117 mV. The effective dielectric constant at the water – AOT micelle interface has been determined spectrophotometrically by using different probes and is estimated to be ~ 54 ± 4. The polarity determined at the micellar interfaces shows dependence on the probe used, which is considered to be due to different solubilization sites for different probes. Methyl red and pyrene probes are not found to be suitable for estimating the dielectric constant.

Keywords: Solution chemistry, Surface potentials, Dielectric constants, Surfactants, Ionic surfactants, Anionic surfactants, Micellar interface, Polarity

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 781-787

 

 

Kinetic assessment of relative counterion penetration into cationic micelles: Effects of inert salt on the rate of piperidinolysis of phenyl salicylate in alkaline cationic micellar medium

M Niyaz Khan* & Emran Ismail

Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia
Email: niyaz@um.edu.my

Received 28 January 2009; revised and accepted 19 May 2009

Pseudo-first order rate constants for piperidinolysis of ionized phenyl salicylate, obtained at 0.1 M piperidine, constant concentration of CTABr micelles and varying values of [NaOC6H4CO2Na], follow the empirical relationship: kobs = (k0 + q KX/S[MX])/(1 + KX/S[MX]), where q and KX/S are empirical constants, MX = NaOC6H4CO2Na and k0 = kobs at [MX] = 0. The values of q and KX/S are explained in terms of pseudophase micellar model coupled with an empirical relationship: KS = KS0/(1 + KX/S[MX]), where KX/S is an empirical constant and KS and KS0 are CTABr micellar binding constants of PS- (i.e., S = PS-) in the presence and absence of MX, respectively.

Keywords: Kinetics, Reaction mechanisms, Micellar reactions, Counterion penetration, Micellar penetration, Piperidinolysis

IPC Code: Int. Cl.8 C07B41/00

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 788-792

 

 

Gas-phase catalytic synthesis of MTBE from MeOH and ButOH over various microporousH-zeolites

Q Zhanga, Q-H Xiaa, *, X-H Lua, X-T Mab & K-X Sub

aMinistry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, Hubei University, Wuhan 430062, China

Email: xia1965@yahoo.com

bJingchu University of Technology, Jingmen 448000, China

Received 31 October 2008; revised and accepted 12 May 2009

Several H-zeolites such as HZSM-5, HY, Hb, H-13X, H-K10 and HA have been used to catalyze the gas-phase synthesis of methyl tert-butyl ether from methanol and tert-butanol in a continuous fixed-bed reactor. The ascending sequence of Brönsted acidity is: H-K10 (0.86) < Hb (2.04) < H-13X (2.83) < HY (3.93) < HZSM-5 (5.22), which is appreciably different from the order of Lewis acidity: H-K10 (0.87) < HZSM-5 (1.15) < H-13X (1.75) < HY (4.94) < Hb (6.10). The optimal reaction temperature varies in the order: Amberlyst-15 (80-110 °C) » Hb (80-90 °C) < HZSM-5 (120 °C) < HY (140-150 °C) < H-K10 (150 °C) << H-13X (220 °C), and is dependent on several factors. The Hb catalyst shows the best activity and on-stream stability (the selective conversion of >97.4 mol% ButOH to MTBE) at 80-90 °C (comparable to that of commercial Amberlyst-15), along with increasing time-on-stream up to 110 h at 90 °C. The highly selective conversion of ButOH to MTBE remains more or less constant on both the catalysts.

Keywords: Catalysis, Acid catalysis, Gas phase synthesis, Zeolites, H-zeolites, Microporous zeolites

IPC Code: Int. Cl.8 B01J29/40; C10L1/85; C10L10/10

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 793-796

 

 

Preparation of a novel monolithic catalyst CuO-CeO2 and its catalytic property in VOC oxidation

 

Zhu-nian Jina, b, * & Yu-peng Songa

aJinhua College of Profession and Technology, Jinhua 321007, China

Email: jzn@chem.jhc.cn

bInstitute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China

Received 17 March 2009; revised and accepted 21 May 2009

A novel monolithic CuO-CeO2 catalyst has been prepared and tested for catalytic combustion of volatile organic compounds as a model reaction. The catalyst exhibits high catalytic activity in ethyl acetate and CO oxidation. The interaction between CeO2 and CuO may be responsible for the catalytic activity.

Keywords: Catalysts, Monolithic catalysts, VOC, Oxides, Copper oxides, Cerium oxides

IPC Code: Int. Cl.8 B01J 21/00

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 797-800

 

 

Kinetics and mechanism of oxidation of formic and oxalic acids by
bis(pyridine) silver permanganate

Jayshree Banerjia, Laszlo Kotaib & Kalyan K Banerjic, *

aDepartment of Biotechnology, Meerut Institute of Engineering and Technology, Meerut 250 005, India

bChemical Research Center, Hungarian Academy of Sciences, H-1025, Pusztaszeri u. 59-67, Budapest, Hungary

cFaculty of Science, National Law University, Mandore, Jodhpur 342 304, India

Email: kalyanbanerji@yahoo.com

Received 23 January 2009; revsied and accepted 5 May 2009

Kinetics and mechanism of oxidation of formic and oxalic acids by bis(pyridine) silver permanganate in aqueous acetic acid have been studied. The main product of oxidation is carbon dioxide. The reaction is first order each with respect to the permanganate and the reductant. The reaction is catalyzed by hydrogen ions. The oxidation of adeuterioformic acid exhibits a substantial primary kinetic isotope effect (kH/kD = 3.69 at 298 K). Suitable mechanisms have been proposed.

Keywords: Kinetics, Reaction mechanisms, Oxidations

IPC Code: Int. Cl.8 C07B 33/00

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 801-805

 

 

Linear solvation energy relationship in the reaction between phenacyl bromide and N-methyl aniline

B Ramesh, D Vijaya Bharathi, B Kavitha & P Manikyamba*

Department of Chemistry, Kakatiya University, Warangal 506 009, AP, India

Email: mani_prerepa@yahoo.co.in

Received 3 November 2008; revised and accepted 27 April 2009

The reaction between phenacyl bromide and N-methyl aniline has been studied conductometrically in 17 different protic and aprotic solvents. The reaction is overall second order, being first order with respect to each reactant. Correlation of the second order rate constants with different solvent parameters indicates that the solvation of the reactants and the transition state is due to non-specific polarity of the solvent, hydrogen bond donor ability, solvent nucleophilicity, and electrophilicity of the solvent. By statistical analysis, a linear solvation energy relationship is derived and the percentage contribution of each type of solvation is estimated.

Keywords: Solution chemistry, Solvation energy, LSER

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 806-811

 

 

Partial molar volumes of oxalic acid and its salts in water-rich binary aqueous mixtures of methanol

M L Parmar* & M K Guleria

Department of Chemistry, Himachal Pradesh University, Summer Hill, Shimla 171 005, India

Email: hb_kutlehria@yahoo.co.in

Received 26 December 2008; revised and accepted 14 May 2009

Partial molar volumes of oxalic acid and its salts, viz., ammonium oxalate, sodium oxalate and potassium oxalate, have been determined in different compositions of water-rich binary aqueous mixtures of methanol (3, 6, 9, 12, and 15 wt. percent of methanol) from solution density measurements at 298.15 K and in 3% (w/w) methanol + water at different temperatures. The data have been analysed by using Masson equation and the obtained parameters have been interpreted in terms of ion-solvent and ion-ion interactions. The partial molar volumes vary with temperature as a power series of temperature. Structure making/breaking capacities of the electrolytes have been inferred from the sign of , i.e. the second derivative of partial molar volume with respect to temperature at constant pressure. Oxalic acid and its salts act as structure breakers in binary aqueous mixtures of methanol.

Keywords: Solution chemistry, Thermodynamics, Partial molar volumes, Ion-solvent interactions, Solvent-solvent interactions, Oxalates

 

 

Indian Journal of Chemistry

Vol. 48A, June 2009, pp. 812-816

 

 

Simultaneous kinetic determination of paracetamol and caffeine using Cu(II)-neocuproine in presence of dodecyl sulfate
by H-point standard addition method

H Tavallali* & M Sheikhaei

Payame Noor University (PNU), Shiraz, 71365-944, Iran

Email: tavallali@pnu.ac.ir, tavallali@yahoo.com

Received 6 Aug 2008; re-revised and accepted 18 May 2009

A simple, feasible and selective kinetic spectrophotometric method for simultaneous determination of paracetamol and caffeine using H-point standard addition method is described. The method is based on difference in the rate of oxidation of the compounds with Cu(II)-neocuproine system and formation of Cu(I)–neocuproine complex, which is monitored at 453 nm and at pH 5.0 in the presence of sodium dodecyl sulfate. Experimental conditions such as pH, reagents concentrations, ionic strength and temperature have been optimized. Paracetamol and caffeine can be determined in the range 1.5-7.0 and 0.1-3.0 μg ml-1 respectively. The proposed method has been applied for the determination of paracetamol and caffeine in pharmaceutical samples with satisfactory results.

Keywords: Analytical chemistry, Spectrophotometry, H-point standard addition, Paracetamol, Caffeine, Neocuproine

IPC Code: Int Cl.8 G01N21/25