Indian Journal of Chemistry

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

Total visitors: 5,297  since 04-04-08

 

VOLUME 47A

NUMBER 4

APRIL 2008

CONTENTS

Advances in Contemporary Research

 

495

 

Ionic liquids: Physico-chemical, solvent properties and their applications in chemical processes

 

 

 

 

 

Geetanjali Singh & Anil Kumar*

 

 

 

 

Ionic liquids, a new class of compounds, have recently emerged as potential substitutes for volatile organic solvents. Ionic liquids possess certain special physico-chemical characteristics that render them very useful in different areas of research and development. The physico-chemical properties and the applications of ionic liquids in chemical processes are critically discussed.

 

Papers

 

504

 

Electrocatalytic properties of platinum catalyst for methanol electrooxidation enhanced by nafion-thionine ion-pair

 

 

 

 

 

 

 

 

 

 

 

 

 

Xinxian Zhong, Jinhua Chen*, Lei Yang &
Xinping Sun

 

 

 

 

The potential of Nf-Th ion-pair as a dispersant and second catalyst to improve the electrocatalytic properties of Pt catalyst  has been investigated. The peak current density of methanol oxidation on the NfThPt/C/graphite electrode is about 7.25 and 3.04 times as high as that on the E-TEK Pt/C/graphite and E-TEK PtRu/C/graphite electrodes, respectively.

 

 

 

510

 

Organotin(IV) triazolates as molecular precursors for pure-phase, nanosized SnS/SnO2 through pyrolysis

 

 

 

 

 

 

 

 

 

 

 

Mala Nath* & Sulaxna

 

 

 

 

The thermal decomposition of organotin(IV) triazolates of general formula, R2SnL2, provides a simple route to prepare nanosized semiconductors, viz., SnS and SnO2, in nitrogen and air atmosphere, respectively. The crystallite average size of the residues is found in the range of 6-63 nm.

 

 

 

 

517

 

Bis(o-vanillin)benzidine(o-v2bzH2) as a binucleating ligand: Synthesis, characterization and 3D molecular modeling and analysis of some binuclear complexes of o-v2bzH2 with copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), samarium(III) and dioxouranium(VI)

 

 

 

 

 

 

 

 

 

 

 

 

R C Maurya*, J Chourasia & P Sharma

 

 

 

 

A binucleating tetradentate Schiff base ligand,
bis(o-vanillin)benzidine (o-v2bzH2), and its new binuclear complexes of the type [M(o-v2bz)]2.nH2O [where M = Cu(II), Ni(II), Co(II), Zn(II), Mn(II) or UO2(VI)] and
[Sm(o-v2bz)(OAc)(H2O)]2 have been synthesized and characterized.

 

 

 

529

 

Synthesis and spectroscopic studies of axially
ligated aluminium(III)-p-methyl-meso-tetraphenyl-porphyrins

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sunesh Dubey, Gauri D Bajju*, Rabia Javed & Tabraiz Sadiq

 

 

 

 

Reaction of p-methyl-meso-tetraphenylporphyrin with aluminium(III) acetylacetonate and phenol affords the corresponding axially ligated aluminium(III)-p-methyl-meso-tetraphenylporphyrin.

 

 

 

Notes

 

535

 

Computing Sadhana polynomial of V-phenylenic nanotubes and nanotori

 

 

 

 

 

 

 

 

 

 

 

A R Ashrafi*, M Ghorbani & M Jalali

 

 

 

 

The Sadhana polynomial,  where m(G, c) is the number of strips of length c, has been defined to evaluate the Sadhana index of a molecular graph. The relation between this new polynomial and Omega polynomial is investigated. A method for computing Sadhana polynomial and then Sadhana index for V-phenylenic nanotubes and nanotori with given parameters m and n has been described.

 

 

538

 

PI, Szeged and edge Szeged indices of an infinite family of nanostar dendrimers

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ali Reza Ashrafi* & Mahsa Mirzargar

 

 

 

 

The PI and Szeged indices of a class of nanostar dendrimer are computed.

 

542

 

Density functional theory study on the interaction between formamide and adenine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hai-tao Sun, Ke Tang, Zhi-zhong Wang &
Zheng-yu Zhou*

 

 

 

 

The hydrogen bonding of complexes formed between formamide and adenine molecules has been investigated using density functional theory method at 6-311++G(d, p) level. Nine stable cyclic structures, with two hydrogen bonds being involved in the interaction, have been found on the potential energy surface.

 

 

 

548

 

The basicities of a series of substituted acetophenones in the ground state: A DFT study

 

 

 

 

 

 

 

 

U Senapati, D De & B R De*

 

 

 

 

The basicities of a series of p-substituted acetophenones (aromatic conjugated system) and their O-protonated counterparts have been computed using density functional theory (Becke, Lee, Yang and Parr [B3LYP]) method and 6-311G(d,p) basis sets with complete geometry optimization. The gas phase O-protonation is observed to be exothermic and the local stereochemical disposition of the proton is found to be almost the same in each case.

 

 

 

551

 

Non-ionic micellar inhibition on the rate of oxidation of l-histidine by alkaline hexacyanoferrate(III)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ratna Shukla & Santosh K Upadhyay*

 

 

 

 

 

556

 

Thermodynamics and kinetic studies of insertion reaction between CCl and NH3

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Weijiang Si & Shuping Zhuo *

 

 

 

 

Based on the quantum theoretical study of the insertion reaction of CCl with NH3, the thermodynamic functions, the equilibrium constants, A factors and the rate constants in the temperature range 200-2000K have been computed using statistical thermodynamics and Eyring transition state theory with Wigner correction. Results show that the reaction is thermodynamically dominant at low temperatures and kinetically favored at higher temperatures.

 

 

 

560

 

Synthesis, structural characterization of new macrocyclic Schiff base derived from 1,6-bis-
(2-formylphenyl)hexane and 2,6-diaminopyridine and its metal complexes

 

 

 

 

 

 

 

 

 

 

 

 

 

Salih İlhan*, Hamdi Temel, Murat Sunkur & İbrahim Teğin

 

 

 

 

A macrocyclic ligand has been synthesized by reaction of
2,6-diaminopyridine and 1,6-bis(2-formylphenyl)hexane. Metal complexes have been synthesized by the reaction of the ligand and M(ClO4)2.6H2O, where M = Cu(II), Ni(II), Pb(II), Zn(II), Cd(II) and La(III). The Cu(II) complex is binuclear while all the other complexes are diamagnetic.

 

 

Authors for correspondence are indicated by (*)


Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 495-503

 

Ionic liquids: Physico-chemical, solvent properties and their applications in chemical processes

Geetanjali Singh & Anil Kumar*

Received 27 February 2008

A new class of compounds, called as ionic liquids, has recently emerged as potential substitute for volatile organic solvents. Ionic liquids possess certain special physico-chemical characteristics that render them very useful in different areas of research and development. In this review, the physico-chemical properties and the applications of ionic liquids in chemical processes are critically discussed and recommendations made for probing further the poorly understood aspect of this newly emerging class of compounds.

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 504-509

 

Electrocatalytic properties of platinum catalyst for methanol electrooxidation enhanced by nafion-thionine ion-pair

Xinxian Zhong, Jinhua Chen*, Lei Yang & Xinping Sun

Received 29 June 2007; revised 21 February 2008

Nafion (Nf)-thionine (Th) ion-pair as dispersant and second catalyst has been introduced in Pt catalyst for methanol electrooxidation and the resulting catalyst supported on carbon (NfThPt/C) has been investigated by electrochemical method. For the same loading mass of Pt, the peak current density of methanol oxidation on the NfThPt/C/graphite electrode is about 7.25 and 3.04 times as high as that on the E-TEK Pt/C/graphite and E-TEK PtRu/C/graphite electrodes, respectively. Moreover, NfThPt/C catalyst shows excellent anti-poisoning ability and long-term cycle stability. The electrocatalytic properties of Pt for methanol electrooxidation are improved by Nf-Th ion-pair.

IPC Code: Int. Cl. 8 B01J23/42; C25B3/02

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 510-516

 

Organotin(IV) triazolates as molecular precursors for pure-phase, nanosized SnS/SnO2 through pyrolysis

Mala Nath* & Sulaxna

Received 29 September 2007; revsied 10 March 2008

The thermal decomposition of organotin(IV) triazolates of general formula R2SnL2 (R = methyl (1), n-butyl (2), n-octyl (3) and phenyl (4)) and R3SnL (R = Me (5); and L = anion of 3-amino-5-mercapto-1,2,4-triazole) provides a simple route to prepare nanosized semiconductors, SnS and SnO2 in nitrogen and air atmosphere, respectively, at low temperature 600-700 ēC. The crystallite average size of the residues determined by X-ray diffraction line broadening is found in the range of 6-63 nm. The particle size of the residues obtained by the pyrolysis of 2 and 4 (in nitrogen) has also been determined by tunneling electron microscope and found to be in the range 2-55 nm. The surface morphology of these residues has been determined by scanning electron microscopy. The thermogravimetric analysis shows that the weight loss observed in nitrogen is higher than that expected for the formation of SnS as end-product. This indicates the partial loss of the residue to the gas phase due to sublimation at higher temperature. Kinetic studies of 2 and 4 in air indicate the first order kinetics for the decomposition process. The X-ray diffraction, SEM and TEM results of the residues along with kinetic parameters show that 5 and 2 are the best precursors for production of pure phase nanosized SnO2 followed by 3 in air whereas 4 is the best precursor for SnS followed by 2 in nitrogen. These compounds are much better precursors for production of pure phase nanosized SnO2/SnS as compared to diorganotin(IV) thiadiazolates.

IPC Code: Int. Cl.8 B82B

Indian Journal of Chemistry

Vol. 47, April 2008, pp. 517-528

 

Bis(o-vanillin)benzidine(o-v2bzH2) as a binucleating ligand: Synthesis, characterization and 3D molecular modeling and analysis of some binuclear complexes of o-v2bzH2 with copper(II), nickel(II), cobalt(II), manganese(II), zinc(II), samarium(III) and dioxouranium(VI)

 

R C Maurya*, J Chourasia & P Sharma

Received 22 June 2006; re-revised 4 March 2008

A binucleating tetra-dentate Schiff base ligand, bis(o-vanillin)benzidine (o-v2bzH2), and its seven new binuclear complexes have been synthesized and characterized on the basis of elemental analysis, IR, NMR, electronic, magnetic, thermal studies and conductance measurements. The compositions of these complexes are found to be
[M(o-v2bz)]2.nH2O, where M = Cu(II), Ni(II), Co(II), Zn(II), Mn(II) or UO2(VI), and [Sm(o-v2bz)(OAc)(H2O)]2. The
1H NMR spectrum of one of the compounds, [Zn(o-v2bz)]2, shows the absence of proton signal for phenolic oxygen (-OH). Low magnetic moment values, high thermal stability and insolubility in common organic solvents support the binuclear structure of these complexes. Suitable binuclear structures have been assigned. The 3D molecular modeling and analysis for bond lengths and bond angles have also been carried out of one of the representative compounds, [Ni(o-v2bz)] 2.

IPC Code: Int. Cl.8 C07F1/08; C07F3/06; C07F5/00; C07F13/00; C07F15/04; C07F15/06

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 529-534

 

Synthesis and spectroscopic studies of axially ligated aluminium(III)-p-methyl-meso-tetraphenylporphyrins

Sunesh Dubey, Gauri D Bajju*, Rabia Javed & Tabraiz Sadiq

Received 3 July 2007; revised 5 March 2008

Treatment of p-methyl-meso-tetraphenylporphyrin (p-CH3TPP) with aluminium(III) acetylacetonate (Al(acac)3) and phenol affords the corresponding axially ligated aluminium(III)-p-methyl-meso-tetraphenylporphyrin (Al(III)-p-CH3TPP). The separation and isolation of these derivatives have been achieved through chromatographic methods. The free base porphyrin and its axially ligated Al(III) derivatives are characterized by various spectroscopic techniques.  1H NMR spectra shows that the protons of the phenolic rings axially attached to the central metal ion are merged with the protons of the tetraphenyl ring of the porphyrin. The visible spectrum of axially ligated Al(III)p-methyl-meso-tetraphenylporphyrins show two bands, i.e., Q-bands. In axially ligated Al(III) derivatives, B and Q-bands exhibit a red shift on increasing the polarity of the solvent. The emission bands of axially ligated compounds are blue-shifted compared to free-base porphyrin but in the presence of an electron-accepting group axially attached to Al(III), the emission spectra is marginally red-shifted compared to other porphyrin compounds.

IPC Code: Int. Cl.8 C07D487/22; C07F5/06

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 535-537

 

Computing Sadhana polynomial of V-phenylenic nanotubes and nanotori

A R Ashrafi*, M Ghorbani & M Jalali

Received 23 February 2007; revised 24 March 2008

The Sadhana polynomial is defined as  where m(G, c) is the number of strips of length c. This new polynomial has been defined to evaluate the Sadhana index of a molecular graph. The relation between this new polynomial and Omega polynomial is investigated. In particular, a method of computing Sadhana polynomial and then Sadhana index for V-phenylenic nanotubes and nanotori with given parameters m and n has been described.

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 538-541

 

PI, Szeged and edge Szeged indices of an infinite family of nanostar dendrimers

 

Ali Reza Ashrafi* & Mahsa Mirzargar

Received 21 November 2007; revised 28 February 2008

A topological index of a graph G is a numeric quantity related to G which describes the molecular graph G. A dendrimer is an artificially manufactured or synthesized molecule built up from branched units called monomers. The PI and Szeged indices of a class of nanostar dendrimer are computed.

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 542-547

 

Density functional theory study on the interaction between formamide and adenine

Hai-tao Sun, Ke Tang, Zhi-zhong Wang & Zheng-yu Zhou*

Received 5 June 2007; revised 5 March 2008

The hydrogen bonding of complexes formed between formamide and adenine molecules has been investigated using density functional theory method at 6-311++G(d, p) level. Nine stable cyclic structures with two hydrogen bonds being involved in the interaction have been found on the potential energy surface. According to the different hydrogen donors offered by formamide molecules, the nine complexes can be divided into two groups. For AF1-AF5, the hydrogen donors are carbon atoms of the formamide molecules, while the nitrogen atoms act as the hydrogen donors in AF6-AF9. The complex AF6 is most stable amongst all the complexes and N8 atom and N9-H15 group form the strongest hydrogen bonds. The hydrogen bonds with the participation of C3-H11 group are the weakest. The vibrational frequency shifts and IR intensities shifts are also reported.

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 548-550

 

The basicities of a series of substituted acetophenones in the ground state: A DFT study

 

U Senapati, D De & B R De*

Received 23 July 2007; revised 24 March 2008

A detailed study of the basicities of a series of p-substituted acetophenones(aromatic conjugated system) and their O-proto­nated counterparts has been performed using density functional theory (Becke, Lee, Yang and Parr [B3LYP]) method and 6-311G(d,p) basis sets with complete geometry optimization. The gas phase O-protonation is observed to be exothermic and the local stereochemical disposition of the proton is found to be almost the same in each case. The presence of p-substituent is seen to cause very little change of the protonation energies, relative to the unsubstituted acetophenones. Computed protonation energies are sought to be correlated with a number of computed system parameters such as the net charge on the carbonyl oxygen of the unprotonated bases, charge on the carbonyl oxygen and charge on the proton of the protonated bases. The overall basicity is explained by distant atom contribution in addition to the contribution from the carbonyl group.

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 551-555

 

Non-ionic micellar inhibition on the rate of oxidation of l-histidine by alkaline hexacyanoferrate(III)

 

Ratna Shukla & Santosh K Upadhyay*

Received 18 September 2007; revised 24 March 2008

The effect of non-ionic surfactants, viz., triton X-100, tween-80 and brij-35 on the rate of oxidation of l-histidine by hexacyanoferrate(III) in alkaline medium has been studied spectrophotometrically in the temperature range 35-55°C. The rate of oxidation is strongly inhibited in presence of non-ionic micelle. The reaction follows a complex kinetics showing a first order dependence of rate with respect to both, alkali and l-histidine. During a particular kinetic run, a second-order dependence of rate with respect to hexacyanoferrate(III) is observed while an increase in initial [hexacyanoferrate(III)] or an addition of hexacyanoferrate(II) in the reaction mixture results in a decrease in the observed rate constant. A suitable mechanism has been proposed and the kinetic data accounted for by the association/distribution of the substrate in micellar and aqueous pseudo-phase. The binding parameters have also been evaluated.

IPC Code: Int.Cl.8 C07B33/00

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 556-559

 

Thermodynamics and kinetic studies of insertion reaction between CCl and NH3

 

Weijiang Si & Shuping Zhuo *

Received 12 June 2007; revised 12 March 2008

Based on the quantum theoretical study of the insertion reaction of CCl with NH3, the statistical thermodynamics and Eyring transition state theory with Wigner correction are used to compute the thermodynamic functions, the equilibrium constants, A factors and the rate constants in the temperature range 200-2000K. Results show that the reaction is thermodynamically dominant at low temperatures and kinetically favoured at higher temperatures.

 

Indian Journal of Chemistry

Vol. 47A, April 2008, pp. 560-564

 

Synthesis, structural characterization of new macrocyclic Schiff base derived from 1,6-bis(2-formylphenyl)hexane and 2,6-diaminopyridine and its metal complexes

Salih İlhan*, Hamdi Temel, Murat Sunkur & İbrahim Teğin

Received 25 January 2008; revised 17 March 2008

A macrocyclic ligand has been synthesized by reaction of 2,6-diaminopyridine and 1,6-bis(2-formylphenyl)hexane. Its complexes with Cu(II), Ni(II), Pb(II), Zn(II), Cd(II) and La(III) have been synthesized by the reaction of ligand and Cu(ClO4)2.6H2O, Ni(ClO4)2.6H2O, Pb(ClO4)2.6H2O, Zn(ClO4)2.6H2O, Cd(ClO4)2.6H2O and La(ClO4)3.6H2O, respectively. The ligand and its metal complexes have been characterized. All complexes are diamagnetic while the Cu(II) complex is binuclear.

IPC Code: Int. Cl.8 C07F1/08; C07F3/06; C07F3/08; C07F5/00; C07F7/00; C07F15/04