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 51A

NUMBER 12

DECEMBER 2012

 

CONTENTS

 

 

1663

 

Catalytic activity of liquid phase prepared Cu-Zn-Al catalyst for CO hydrogenation in a fixed bed reactor

 

 

 

 

 

 

 

 

Chunhui Luan, Anrong Zhang, Xiaodong Wang,
Wei Huang* & Lihua Yin

 

 

 

 

 

 

 

1669

 

Accelerated polymorphous transformations of alumina induced by copper ions impede spinel formation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E Kiss*, S Ratković , Dj Vujičić & G Boskovic

 

 

 

Zinc and magnesium ions decelerate polymorphous transformations of alumina along with decreased degree of sintering relative to the transformation of pure aluminum sample. In contrast, copper ions accelerate polymorphous transformations of alumina, and consequently the corresponding copper-alumina spinel formation is slower.

 

 

 

 

1677

 

Effect on thermal behaviour of polyamide 66/clay nanocomposites with inorganic flame retardant additives

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sudesh Rathi & J B Dahiya*

 

 

 

PA66/30B nanocomposite is thermally stable at temperatures higher than 450 C with increase in char yield due to formation of nanocomposite and hindered diffusion of volatile decomposition products. Addition of zinc borate along with organic phosphinate induces a change in path of thermal decomposition leading to higher char formation which may protect the polymer from burning.

 

 

 

 

 

1686

 

Theoretical study of inclusion complexation of tricylic antidepressant drugs with β-cyclodextrin

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M Jude Jenita, A Antony Muthu Prabhu &
N Rajendiran
*

 

 

 

The inclusion process of four tricyclic antidepressant drugs (carbamazepine, imipramine, dothiepin and doxepin) with
β-cyclodextrin as well as their possible interaction types have been investigated theoretically. Data suggest that these drugs are partially encapsulated into the β-CD cavity. Formation of the inclusion complex is an enthalpy-driven process in gas phase.

 

 

 

 

Notes

 

1695

 

Synthesis, crystal structure, spectroscopic and superoxide dismutase activity of copper(II) and nickel(II) complex of N'-[phenyl(pyridin-2-yl)-methylidene]benzohydrazone

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R N Patel *, Vishnu P Sondhiya, Dinesh K Patel,
K K Shukla & Y Singh

 

 

 

Two binary copper(II) and nickel(II) complexes of hydrazone Schiff base ligand (N'-[phenyl(pyridin-2-yl)methylidene]benzohydrazone) have been synthesized and characterized. The complexes crystallize in monoclinic crystal system having space group P21/c.
The observed trend in spin-Hamiltonian parameters, g> g > 2.03, indicates a dx2-y2 ground state in the copper complex.

 

 

 

 

1701

 

Alkaline hydrolysis of isatin in the presence of mixed CTAB and Triton X-100 micellar systems: Micellisation and kinetic investigations

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

V Srikanth, P Shyamala*, A Satyanarayana &
P V Subba Rao
b

 

 

 

Micellisation behaviour of mixed surfactants of CTAB and
Triton X-100 in the presence of isatin has been studied by surface tension measurements over a wide range of Triton X-100 mole fractions and total surfactant concentrations. The average interaction parameter evaluated using Rubingh theory is 0.396, indicating synergistic behaviour in the mixed micelles.

 

 

 

1706

 

Spectrofluorimetric study on inclusion interaction of
β-cyclodextrin with duloxetine and its analytical application

 

 

 

 

 

 

 

 

 

 

 

Wieslawa Misiuk*

 

 

 

A new sensitive spectrofluorimetric method is proposed for determination of duloxetine based on increase in fluorescence intensity in presence of β-cyclodextrin. The method has a limit of detection of 2.010-8 mol/L, linear range as 5.1610-8 mol/L to
110-5 mol/L and correlation coefficient of 0.9998.

 

 

1711

 

Annual Index

 

 

 

 

 

 

Authors for correspondence are indicated by (*)

 

Indian Journal of Chemistry

Vol. 51A, December 2012, pp. 1663-1668

 

 

Catalytic activity of liquid phase prepared Cu-Zn-Al catalyst for
CO hydrogenation in a fixed be
d reactor

Chunhui Luana, b, Anrong Zhangb, Xiaodong Wanga, Wei Huanga, * & Lihua Yina

aKey Laboratory of Coal Science and Technology Ministry of Education and Shanxi Province,
Taiyuan 030024, Shanxi, China

Email:huangwei@tyut.edu.cn

 

bCollege of Chemistry and Chemical Engineering, Taiyuan University of Technology,
Taiyuan 030024, Shanxi, China

 

Received 9 March 2012; revised and accepted 26 November 2012

 

Cu-Zn-Al catalyst prepared by a complete liquid phase technology for CO hydrogenation has been investigated in a fixed bed reactor in terms of catalytic performance and compared with catalysts prepared by a traditional method such as co-precipitation. The catalysts are characterized by XRD, NH3-TPD, H2-TPR and XPS. Results show that the activity of the liquid phase prepared catalyst is much lower in fixed bed reactor than in a slurry reactor. It was also much lower than that of the catalyst prepared by co-precipitation, although its stability is higher. XPS and XRD characterization reveal that there are obvious differences in the structure, morphology and surface state of the catalysts prepared by the two methods. In the catalyst prepared by liquid phase technology, Cu exists in the form of metallic Cu even though the catalyst is unreduced and there are more acid sites and more carbon on its surface than on the surface of the co-precipitation catalyst. It is concluded that there is a surface carbon film covering the liquid phase catalyst, and the carbon film is an important reason for the low activity when the catalyst is applied to fixed bed reactor. Coke burning off, an effective way for removing the surface carbon, improves the catalyst activity in a fixed reactor.

Keywords: Catalysts, Liquid phase catalysts, Fixed bed reactor, Carbon monoxide hydrogenation, Copper, Zinc, Aluminium

 

Indian Journal of Chemistry

Vol 51A, December 2012, pp. 1669-1676

 

Accelerated polymorphous transformations of alumina induced by
copper ions impede spinel formation

E Kiss*, S Ratković, Dj Vujičić & G Boskovic

University of Novi Sad, Faculty of Technology, Bulevar cara Lazara 1, 21000 Novi Sad, Serbia

Email: ekiss@tf.uns.ac.rs

Received 17 April 2012; revised and accepted 22 November 2012

Slower copper spinel formation on alumina type supports relative to zinc and magnesium spinel formation has been investigated. Spinel formation occurs at high temperatures and is usually accompanied by polymorphous transformations of alumina support and sintering. In samples containing zinc and magnesium ions, decelerated polymorphous transformations of alumina occur relative to the transformation of pure aluminum sample. The impeded phase transformation of alumina coincides with decreased degree of sintering. In contrast, copper ions accelerate polymorphous transformations of alumina, and consequently the corresponding copper-alumina spinel formation is slower. Accelerated sintering may be explained by accelerated phase transformation of alumina, which itself is caused by copper ions slowing down spinel formation.

Keywords: Alumina, Polymorphous transformations, Spinels, Sintering, Copper, Magnesium, Zinc

 

 

 

Indian Journal of Chemistry

Vol. 51A, December 2012, pp. 1677-1685

 

 

Effect on thermal behaviour of polyamide 66/clay nanocomposites
with inorganic flame retardant additives

Sudesh Rathi & J B Dahiya*

Department of Chemistry, Guru Jambheshwar University of Science & Technology, Hisar 125 001, India

Email: jbdic@yahoo.com

Received 9 November 2011; re-revised and accepted 4 November 2012

Polyamide 66 (PA66)/clay nanocomposites have been prepared with inorganic additives by melt blending method using an extruder. Inorganic additives such as potassium nitrate, zinc borate and magnesium hydroxide along with organic phosphinate have been used to study their effect on thermal behaviour of PA66/clay nanocomposites. The nanocomposites have been characterized by XRD which confirms the formation of intercalated and/or exfoliated nanocomposites. The thermal degradation behaviour of nanocomposites has been studied by TG, DTA, DSC and FTIR. PA66/30B nanocomposite is thermally stable in the higher temperature range beyond 450 C with increase in char yield due to formation of nanocomposite and hindered diffusion of volatile products. DSC curve of PA66/30B shows an endothermic peak at 452 C with higher heat of absorption (378 J/g) during the decomposition stage due to intercalation of PA66 between the 30B interlayers. The presence of a band in the FTIR spectrum in the range 2224−2245 cm-1 in all PA66 nanocomposites char residue samples at 400 C indicates the presence of nitrile group in the degradation products of PA66. The addition of zinc borate along with organic phosphinate induces a change in path of decomposition of polymer, leading to higher char formation which may protect the polymer from burning.

Keywords: Organoclays, Composites, Nanocomposites, Clay composites, Polyamide 66, Thermal stability,
Flame retardants

 

Indian Journal of Chemistry

Vol. 51A, December 2012, pp. 1686-1694

 

Theoretical study of inclusion complexation of tricylic
antidepressant drugs with β-cyclodextrin

M Jude Jenita, A Antony Muthu Prabhu & N Rajendiran*

Department of Chemistry, Annamalai University, Annamalai nagar 608 002, Tamil Nadu, India

Email: drrajendiran@rediffmail.com

Received 10 February 2012; revised and accepted 18 November 2012

The inclusion process of four tricyclic antidepressant drugs (carbamazepine, imipramine, dothiepin and doxepin) with β-cyclodextrin (β-CD), as well as their possible interaction types have been investigated theoretically. The data suggest that these drugs are partially encapsulated into the β-CD cavity. The formation of the inclusion complex is predicted to be an enthalpy-driven process in gas phase. Different interactions between these drugs and β-CD should be also possible due to their negative binding energy though their distributions differ greatly. Comparative study of the interactions of these drugs with β-CD has been investigated and their obvious differences in binding energy and enthalpy change suggest that the β- CD can identify the stability of the complex.

Keywords: Theoretical chemistry, Cyclodextrin, Tricyclic antidepressant drugs, Inclusion complex,
Molecular recognition

 

 

Indian Journal of Chemistry

Vol. 51A, December 2012, pp. 1695-1700

 

 

Synthesis, crystal structure, spectroscopic and superoxide dismutase
activity of
copper(II) and nickel(II) complex of N '-[phenyl
(pyridin-2-yl)methylidene]benzohydrazone

R N Patel*, Vishnu P Sondhiya, Dinesh K Patel, K K Shukla & Y Singh

Department of Chemistry, APS University, Rewa (MP) 486 003, India

Email: rnp64@ymail.com

Received 30 July 2012; revised and accepted 15 November 2012

Two binary copper(II) and nickel(II) complexes viz., [Cu(L)(HL)]NO3.H2O (1) and [Ni(L)(HL)]NO3.H2O (2) of hydrazone Schiff base ligand (where L/HL = N'-[phenyl(pyridin-2-yl)methylidene]benzohydrazone) have been synthesized and characterized. Both the complexes (1) and (2) and ligand (HL) are structurally characterized using single crystal X-ray diffraction technique. They crystallize in monoclinic crystal system in the space group P21/n. The observed trends in spin-Hamiltonian parameters g>g>2.03 indicates a dx2-y2 ground state in complex (1). In the absorption spectra in 100% DMSO, complex (2) exhibits a d-d transition at ~900 nm, which is assigned to ν1 band (3A2g3T2g in octahedral parentage). Superoxide dismutase activities of both complexes reveal the dismutation of superoxide (O2-).

Keywords: Coordination chemistry, Schiff bases, Keto-enol tautomerism, SOD activity, Electron paramagnetic
resonance, Copper, Nickel

 

Indian Journal of Chemistry

Vol. 51A, December 2012, pp. 1701-1705

 

 

Alkaline hydrolysis of isatin in the presence of mixed CTAB and Triton X-100 micellar systems: Micellisation and kinetic investigations

V Srikantha, P Shyamalaa, *, A Satyanarayanaa & P V Subba Raob

aDepartment of Physical and Nuclear Chemistry & Chemical Oceanography, School of Chemistry,
Andhra University, Visakhapatnam 530 003, India

Email: shyamalapulipaka@rediffmail.com

bDepartment of Chemistry, Gayatri Vidya Parishad, Visakhapatnam 530 008, India

Received 11 May 2012; revised and accepted 16 November 2012

Micellisation behaviour of mixed surfactants of CTAB and Triton X-100 in the presence of isatin has been studied by surface tension measurements over a wide range of Triton X-100 mole fractions and total surfactant concentrations. The average interaction parameter has been evaluated using Rubingh theory and found to be -0.396 indicating synergistic behaviour in the mixed micelles. Kinetic studies showed that the pseudo first
order rate constant increases with increase in mole fraction of Triton X-100 at constant total surfactant concentration
and decreases with increase in total surfactant concentration at constant mole fraction of Triton X-100. Kinetic analysis has been carried out using a Berezin pseudophase model and binding constants determined to explain the micellar effect.

Keywords: Kinetics, Mixed micelles, Alkaline hydrolysis, Micellisation, Synergetic effect

Indian Journal of Chemistry

Vol. 51A, December 2012, pp. 1706-1710

 

 

Spectrofluorimetric study on inclusion interaction of β-cyclodextrin
with duloxetine and its analytical application

Wieslawa Misiuk*

Department of Biology and Chemistry, University of Bialystok, Bialystok, Poland

Email: wiesmisi@uwb.edu.pl

Received 6 October 2011; re-revised and accepted 19 November 2012

Fluorescence study on inclusion interaction of duloxetine in β-cyclodextrin shows significant increase in the fluorescence of duloxetine in the presence of β-cyclodextrin. The effects of pH and cyclodextrin concentration on the fluorescence spectra are reported. Fluorescence spectroscopy of the host-guest interaction between duloxetine and β-cyclodextrin shows formation of inclusion complex with a 1:1 stoichiometric ratio. The changes in fluorescence of duloxetine on inclusion in the hydrophobic β-cyclodextrin cavity is used to calculate its association constants by non-linear regression method. A new spectrofluorometric method is proposed for quantitative determination of duloxetine in dosage forms with limit of detection of 2.0 10-8 mol/L. The linear range is 5.16 10-8 mol/L to 1 10-5 mol/L and correlation coefficient is 0.9998. The accuracy (recovery 99.5100.8 %)
and precision (RSD 0.580.89 %) values of the proposed method are satisfactory.

Keywords: Analytical chemistry, Spectrofluorimetry, Fluorescence, Inclusion complexes, Duloxetine, β-Cyclodextrin