Indian Journal of Chemistry

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

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

 

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VOLUME 50A

NUMBER 11

NOVEMBER 2011

CONTENTS

 

1547

 

Studies on the binding of isoalantolactone to human serum albumin by molecular spectroscopy and modeling

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Yang Sun, Chun-Mei Hu, Guo-Bo Li,
Sheng-Yong Yang, Lu-Sha Liu, Chun-Lei Tan,

Song Wei
, Xiao-Yun Hu, Ying-Yong Zhao*
& Jun Fan
*

 

 

 

Molecular modeling shows that hydrophobic interactions and hydrogen bonds play a major role in binding of isoalantolactone to human serum albumin.

 

 

 

 

 

1555

 

Designing novel donor-acceptor copolymers using genetic algorithm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Vinita Arora & A K Bakhshi*

 

 

 

Genetic algorithm has been used for designing novel binary copolymers based on donor and acceptor polymers, with a common thiophene-based copolymer. Copolymers containing lower concentration of the thiophene copolymer have better intrinsic as well as extrinsic conductivity.

 

 

 

 

 

 

 

 

 

 

1562

 

Synthesis, characterisation and catalytic activities
of vanadium complexes containing ONN donor
ligand (E)-4-[(2-(dimethylamino)ethylimino] methyl-5-(hydroxymethyl)-2-methylpyridin-3-ol

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Mannar R Maurya*, Manisha Bisht &
Fernando Avecilla

 

 

 

Dioxidovanadium(V) complex encapsulated in the cavity of zeolite-Y is an effective catalyst for the oxidation of styrene, cyclohexene, methyl phenyl sulfide and diphenyl sulfide.

 

 

 

 

1574

 

Epoxidation of olefins catalyzed by manganese(II) complexes of Schiff base ligand having N2O coordination sphere

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Averi Guha & Debasis Das*

 

 

 

The catalytic efficiency of mononuclear manganese(II) complexes having two N2O coordination spheres for epoxidation
of (E)-stilbene and styrene using PhIO and NaOCl as terminal oxidants
are influenced not only by their structural features,
but also by the nature of terminal oxidant, substrate as well as
the solvents. Epoxidation proceeds with the formation of two different intermediates,
O=Mn(IV)(L)(X) and Cl-O-Mn(II)(L)(X) [X=NO3/SCN/N(CN)2], in the presence of PhIO and
NaOCl respectively.

 

 

 

 

 

 

Notes

 

1579

 

Performance of ab initio and DFT methods in modeling Diels-Alder reactions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Gaddamanugu Gayatri

 

 

 

The new DFT functionals, viz., M05, M05-2X and MPW1K appear to be well suited to model Diels-Alder reactions for acyclic, cyclic and annelated dienes respectively.

 

 

 

 

 


1587

 

Synthesis of nano-MgO and identification of the destructive product of  its reaction with 2-chloroethyl
phenyl sulfide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bozorgmehr Maddah*, Amir Aminifar &
Hossein Chalabi

 

 

 

Nanocrystalline magnesium oxide prepared by the sol-gel method shows the formation of nano-MgO materials with crystallite size in the range of 5-20 nm and surface area of 336-556 m2/g. It can be used effectively for decontaminating (2-chloroethyl) phenyl sulfide, a mimic of bis(2-chloroethyl) sulfide. Nonpolar media aids material transfer to the reactive surface sites without blocking these sites.

 

.

 

1592

 

A structural study on the cubic crystalline modification of [Cp6Ti6O8][Bu3Sn3S3(SH)3Cl]2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Neetu Singh & Subrato Bhattacharya*

 

 

 

Crystal and molecular structures of a cubic crystalline form of [Cp6Ti6O8][Bu3Sn3S3(SH)3Cl]2 is reported. The cation, [Cp6Ti6O8]2+, is a cluster comprising an octahedron with six Ti(IV) atoms  at the vertices, while the anion is a six membered ring (with alternate Sn and S atoms) having a chair conformation. The crystal undergoes phase transition on cooling.

 

 

 

 

 

1597

 

Guide to Authors

 

 

 

 

Authors for correspondence are indicated by (*)

 

 

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1547-1554

 

Studies on the binding of isoalantolactone to human serum albumin by
molecular spectroscopy and modeling

Yang Suna, Chun-Mei Hua, Guo-Bo Lib, Sheng-Yong Yangb, Lu-Sha Liua, Chun-Lei Tana, Song Weia,
Xiao-Yun Huc, Ying-Yong Zhaod, * & Jun Fana, *

aSchool of Chemical Engineering, Northwest University, No.229 Taibai North Road, Xi’an, Shaanxi 710069, China

Email: fanjun@nwu.edu.cn

bState Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan 610041, China

cDepartment of Physics, Northwest University, No.229 Taibai North Road, Xi’an, Shaanxi 710069, China

dBiomedicine Key Laboratory of Shaanxi Province, Northwest University, No.229 Taibai North Road, Xi’an, Shaanxi 710069, China

Email:zyy@nwu.edu.cn (YYZ)

Received 22 February 2011; revised and accepted 10 October 2011

The interactions between isoalantolactone (IAL) and human serum albumin (HSA) under simulative physiological conditions have been investigated by fluorescence, absorption and circular dichroism spectra. Fluorescence data reveal that the fluorescence quenching of HSA by IAL is the result of formation of the IAL–HSA complex. The thermodynamic parameters, enthalpy change and entropy change for the reaction are calculated to be -34.317 kJ mol–1 and -7.522 J mol–1 K–1, respectively, indicating that the hydrogen bonds and hydrophobic interactions play a dominant role in the binding of IAL to HSA.
The conformational investigation shows that the presence of IAL decreases the α-helical content of HSA and induces the remarkable unfolding of the polypeptides of protein.
Furthermore, displacement experiments using warfarin and ibuprofen indicate that IAL could bind to site I of HSA, which is in agreement with the results obtained from molecular modeling.

Keywords: Bioinorganic chemistry, Isoalantolactone, Human serum albumin, Fluorescence spectroscopy, Molecular modelling, Binding sites

 

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1555-1561

 

Designing novel donor-acceptor copolymers using genetic algorithm

Vinita Arora & A K Bakhshi*

Department of Chemistry, University of Delhi, Delhi 110 007, India

Email: akbakhshi2000@yahoo.com

Received 11 August 2011; revised and accepted 5 October 2011

Using ab initio band structure results of five donor-acceptor polymers, the electronic structure and conduction properties of their novel binary copolymers have been investigated. One of the donor-acceptor polymers based on thiophene (PCNTh) is common in all the copolymers while second one is varied by replacing S atom with CF2, O, SiH2 or CH2 respectively. The effect of substitution on the electronic properties of the copolymer is investigated. In order to calculate the electronic properties of the copolymers and to obtain the copolymer possessing minimum band gap, genetic algorithm is used along with negative factor counting and inverse iteration technique. The copolymer containing CF2 units is found to have the lowest band gap and hence maximum intrinsic conductivity. Investigations involving variation in block sizes of the homopolymer units suggest that copolymers containing lower concentration of PCNTh are better candidates for both intrinsic as well as extrinsic conductivity.

Keywords: Genetic algorithm, Polymers, Conducting polymers, Copolymers, Donor-acceptor polymers, Electronic properties, Band gap, Thiophene

 

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1562-1573

 

Synthesis, characterisation and catalytic activities of vanadium complexes containing ONN donor ligand (E)-4-[(2-(dimethylamino)ethylimino] methyl-5-(hydroxymethyl)-
2-methylpyridin-3-ol

Mannar R Mauryaa, * Manisha Bishta & Fernando Avecillab

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

Email: rkmanfcy@iitr.ernet.in

bDepartamento de Química Fundamental, Universidade da Coruña, Campus de A Zapateira, 15071 A Coruña, Spain

Received 1 May 2011; revised and accepted 12 October 2011

Reaction between [VIVO(acac)2] and the ONN donor ligand (E)-4-[(2-(dimethylamino)ethylimino]methyl-5-(hydroxymethyl)-2-methylpyridin-3-ol (Hpydx-dmen) results in the formation of the complex [VIVO(acac)(pydx-dmen)] (1). In (1), the vanadium center adopts a distorted six-coordinated octahedral geometry where the ligand coordinates through one O and two N atoms; the oxo and two Oacac atoms complete the coordination sphere. The poorly stable oxidoperoxidovanadium(V) complex [VVO(O2)(pydx-dmen)] (2) has been prepared by the treatment of (1) with aqueous
30 % H2O2. Its formation has also been demonstrated in solution by treating (1) with H2O2 in methanol. Treatment of the ligand with vanadium(IV)–exchanged zeolite-Y followed by aerial oxidation gives the dioxidovanadium(V) complex encapsulated in the nano-cavity of zeolite-Y, [VVO2(pydx-dmen)]-Y (3). The encapsulated complex, [VVO2(pydx-dmen)]-Y (3), catalyses the oxidation of styrene, methyl phenyl sulfide, diphenyl sulfide and cyclohexene using H2O2 as oxidant in good yield.

Keywords: Coordination chemistry, Encapsulated compounds, Catalysts, Oxidation, Oxidovanadium, ONN ligands

 

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1574-1578

 

Epoxidation of olefins catalyzed by manganese(II) complexes
of Schiff base ligand having N2O coordination sphere

Averi Guha & Debasis Das*

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

Email: dasdebasis2001@yahoo.com

Received 19 July 2011; accepted 10 October 2011

Three mononuclear manganese(II) complexes having two N2O coordination spheres have been examined as catalysts for epoxidation of (E)-stilbene and styrene using PhIO and NaOCl as terminal oxidants in four different solvents. The catalytic efficiency of the complexes are observed to be influenced not only by their own structural features but also by the nature of terminal oxidant, substrate as well as the solvents. Epoxidation proceeds with the formation of two different intermediates, O=Mn(IV)(L)(X) and Cl-O-Mn(II)(L)(X) [X=NO3/SCN/N(CN)2], in presence of PhIO and NaOCl respectively. Amongst the solvents, acetonitrile is found to be the most suitable.

Keywords: Epoxidation, Solvent effects, Terminal oxidants, Olefins, Manganese, Catalysts, Schiff bases

 

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1579-1586

 

Performance of ab initio and DFT methods in modeling
Diels-Alder reactions

Gaddamanugu Gayatri

Molecular Modeling Group, Organic Chemical Sciences, Indian Institute of Chemical Technology,
Hyderabad 500 607, India

Email gayathrig10@gmail.com

Received 1 May 2011; revised and accepted 18 August 2011

The performance of a range of computational methods in modeling Diels-Alder reactions of acyclic, cyclic and annelated dienes with ethylene has been assessed. The average asynchronicity values, mean, mean absolute deviation and standard deviation values with respect to activation and reaction energies are calculated and the preference for one method over the other is validated. While M05-2X generates less asynchronous transition states, more asynchronous transition states are obtained at M05 level amongst the methods considered. M05/6-311+G(d,p) is found to be adequate in modeling the Diels-Alder reactions involving acyclic systems. M05-2X method in combination with 6-311+G(d,p) basis set is found to be reliable to model the potential energy surface of cyclic systems. For modeling the reactions involving annelated dienes, the MPW1K method along with 6-311+G(d,p) basis set is found to be adequate.

Keywords:   Theoretical chemistry, Diels-Alder reactions, Cycloadditions, Ab initio calculations,
DFT calculations
, Asynchronicity, Activation energy, Reaction energy

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1587-1591

 

Synthesis of nano-MgO and identification of the destructive product of its reaction with 2-chloroethyl phenyl sulfide

Bozorgmehr Maddah*, Amir Aminifar & Hossein Chalabi

Department of Chemistry, Imam Hossein University, Tehran, Iran

Email: bozorgmaddah@yahoo.com

Received 29 March 2011; revised and accepted 23 August 2011

Nanocrystalline magnesium oxide has been prepared by the sol-gel method and characterized by X-ray diffraction, N2-BET, SEM and infrared spectroscopic techniques. Results confirm the formation of nano-MgO materials with crystallite size in the range of 5-20 nm and surface area of 336-556 m2/g. The product has been tested as destructive adsorbent for the decontamination of (2-chloroethyl) phenyl sulfide, a mimic of bis(2-chloroethyl) sulfide ("HD" or mustard gas). Destructive adsorbent reaction has been carried out in heptane and methanol media and investigated by GC-FID and GC-MS techniques. Reaction rate in heptane is observed to be higher than in methanol. It seems that a nonpolar media aids material transfer to the reactive surface sites without blocking these sites.

Keywords: Nanomaterials, Decontamination reaction, Magnesium oxide, Destructive adsorbent

 

 

Indian Journal of Chemistry

Vol. 50A, November 2011, pp. 1592-1595

 

A structural study on the cubic crystalline modification of [Cp6Ti6O8][Bu3Sn3S3(SH)3Cl]2

 

Neetu Singh & Subrato Bhattacharya*

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

Email: s_bhatt@bhu.ac.in

Received 23 May 2011; revised and accepted 6 Oct 2011

Crystal and molecular structures of a cubic crystalline form of [Cp6Ti6O8][Bu3Sn3S3(SH)3Cl]2 have been studied by single crystal X-ray diffraction. The cation, [Cp6Ti6O8]2+ is a cluster comprising an octahedron with six Ti(IV) atoms at the vertices. Each of the eight faces is capped by an oxygen atom. The cluster is electron deficient as it possesses 84 electrons only. The anion is a six membered ring (with alternated Sn and S atoms) having a chair conformation. The crystal undergoes a phase transition on cooling which has been monitored by X-ray diffraction studies.

Keywords: Organometallic compounds, Organotin compounds, X-ray crystallography, Metal clusters, Cyclopentadienyl compounds, NBO calculations, Phase transitions, Tin, Titanium