Indian Journal of Chemistry

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

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VOLUME 47A

NUMBER 3

March 2008

CONTENTS

 

341

 

Vibrational spectra of CT complexes of acridine orange

 

 

 

 

 

 

 

Sagar Agravat, Vishal Jain & A T Oza*

 

 

 

Infrared spectra of acridine orange and its charge transfer complexes with acceptors such as chloranil, 2,3-dichloro-5,6-dicyano-p-benzoquinone, 7,7,8,8-tetracyano-p-quinodimethane  and tetracyano-p-ethylene are reported. Their photo conducting nature is explained with two absorption edges in infrared range associated with non-equivalent sites of chloride ion or formation of bonding, non-bonding and antibonding orbitals.

 

 

348

 

Use of zirconium(IV) phosphate as a solid acid catalyst in some esterification reactions

 

 

 

 

 

 

H K Patel, R S Joshi & U V Chudasama*

 

 

 

Amorphous and crystalline phases of zirconium(IV) phosphate of the class of tetravalent metal acid salts have been synthesized by sol-gel method. The exchangeable protons present in the structural hydroxyl groups indicate their potential as solid acid catalysts.

 

 

353

 

Synthesis, characterization and properties of some ternary copper(II) complexes containing NOS donor Schiff base and NN donor bidentate ligands

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R N Patel*, V L N Gundla & D K Patel

 

 

 

Six ternary copper(II) complexes, viz., [Cu(SAT)(H2O)], [Cu(SAT)(phen)].0.5 H2O, [Cu(SAT)(bipy)], [Cu(SAA)(dmp)], [Cu(SAT)(en)] and [Cu(SAT)(temed)], where SAT = salicylideneaminothiophenol, phen = 1,10-phenanthroline, bipy = 2,2˘-bipyridyl, dmp = 2,9-dimethyl 1,10-phenanthroline, en = ethylenediamine, temed = N,N,N˘,N˘-tetramethylethylinediamine, have been synthesized and characterized.

 

361

 

Mixed-ligand hydrazonato-oxovanadium(V) complexes
incorporating salicylaldehyde as co-ligand

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Tapas Ghosh* & Bipul Mondal

 

 

 

[VIVO(acac)2] reacts with an equimolar amount of tridentate dibasic ONO donor hydrazone ligand, derived from the condensation of benzoyl hydrazine with either
2-hydroxyacetophenone or its para-substituted derivatives, in the presence of excess amount of salicylaldehyde (Hsal) in methanol under aerobic conditions to give the mixed-ligand [VVO(L)(sal)] complexes  in good yields.

 

 

 

369

 

Proton transfer equilibria between disubstituted benzoic acids and carbinol base of crystal violet in apolar aprotic solvents. Chemometric analysis of disubstituent effects on the strength of benzoic acid in chlorobenzene

 

 

 

 

 

 

 

 

 

Susanta K Sen Gupta* & Ruchi Shrivastava

 

 

 

Proton transfer equilibria in chlorobenzene between a set of di-substituted benzoic acids including the corresponding mono-substituted acids and the carbinol base of crystal violet are reported. The effect of disubstitution at ortho- and/or meta- positions on the strength of benzoic acid has been analysed chemometrically on the basis of Fujita Nishioka’s multiparameter approach and the assumption of additivity for substituent effects. The substituent effect is contributed by ordinary electronic and proximity electronic effects in an almost equal ratio (52:48).

 

Notes

 

374

 

Synthesis and spectral characterization of Pb(II) perchlorate complexes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Salih İlhan

 

 

 

Five new Pb(II) perchlorate complexes have been synthesized by reaction of 2,6-diaminopyridine, Pb(ClO4)2.6H2O and dialdehydes in methanol. On the basis of spectral studies, five coordinated and square pyramid geometry may be assigned to the complexes.

 

 

 

[PbL5(ClO4)][ClO4].H2O

 

378

 

Synthesis and characterization of macrocyclic Cd(II) complexes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Salih İlhan* & Hamdi Temel

 

 

 

Ten new Cd(II) complexes have been synthesized with Cd(ClO4)2.6H2O, Cd(NO3)2.6H2O in chloroform-methanol. On the basis of the spectral studies, four-coordinated tetrahedral geometry may be assigned to the complexes.

 

 

 

 

383

 

Electrochemical behaviour of 1, 3-diphenyl-3-hydroxytriazene and its copper complex

 

 

 

 

 

 

 

Manu Gupta, B S Bairwa, Romila Karnawat, I K Sharma & P S Verma*

 

 

 

1,3-Diphenyl-3-hydroxytriazene and its Cu complex have been synthesized and characterized. Cyclic voltammetry studies on glassy carbon electrode as well as Pt electrode at various sweep rates and pH values reveal that DPHT shows six electrons irreversible reduction behaviour while its Cu complex undergoes one electron quasi-reversible electrode reaction.

 

387

 

Cyclohexylation of phenol over a solid acid catalyst comprising 12-tungstophosphoric acid and hydrous zirconia

 

 

 

 

 

Nikunj Bhatt & Anjali Patel*

 

 

 

Cylcohexylation of phenol with cyclohexene has been carried out over 12-tungstophosphoric acid supported on hydrous zirconia under mild conditions. The catalyst shows high activity and selectivity for 2-cyclohexyl phenol. In addition, the catalyst can be recycled and reused.

 

390

 

Proton transfer equilibria between o-substituted benzoic acids and the carbinol base of crystal violet in apolar aprotic solvents: Chemometric analysis of ortho effect

 

 

 

 

 

 

 

 

 

Susanta K Sengupta* & Sangeeta Mishra

 

 

 

Toluene-phase reaction equilibria between a set of
o-substituted benzoic acids and crystal violet carbinol base producing a coloured ion-pair have been studied. Chemometric analysis on the basis of both Charton’s and Fujita-Nishioka’s multiparameter approaches for o-substituent effects on the equilibrium constants show that proximity electronic effect of an o-substituent is the main intrinsic contribution to the anomalous ortho effect with its steric factor contributing merely a minor effect. However, in the aqueous phase the steric contribution becomes significant.

 

394

 

Vitamin K3 encapsulated poly(vinylpyrrolidone) film modified glassy carbon electrode for studying the vitamin K3 – caffeine interaction

 

 

 

 

 

 

 

 

 

Diganta Kumar Das* & Rimki Bhattacharjya

 

 

 

 

 

397

 

Photocatalytic degradation of sunset yellow FCF in presence of some transition metal complexes and hydrogen peroxide

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Savitri Lodha, Abhilasha Jain, V K Sharma & Pinki B Punjabi*

 

 

 

The photocatalytic degradation of sunset yellow FCF by thiocyanate complexes of iron, copper and cobalt and hydrogen peroxide is reported.

 

 

Authors for correspondence are indicated by (*)


Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 341-347

 

Vibrational spectra of CT complexes of acridine orange

Sagar Agravat, Vishal Jain & A T Oza*

Received 4 May 2007; revised 31 January 2008

Infrared spectra of acridine orange and its charge transfer complexes with acceptors such as chloranil, 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) and tetracyano-p-ethylene (TCNE) are reported here. Their photo conducting nature is explained with two absorption edges in infrared range associated with non-equivalent sites of chloride ion or formation of bonding, non-bonding and antibonding orbitals. The mid-IR transition is usually direct and the low-energy transition is indirect. Whether the transition is allowed or forbidden depends on average intermolecular distance. This differs from ordinary ternary complexes in which two acceptors give rise to two conduction bands. Also, there is absence of any screening found in two donor based ternary systems. There is some band tailing of phonon bands in absorption function above Eg. Only TCNQ and TCNE complexes show weak Gaussian bands below 800 cm-1. The repetitions of structures associated with the oscillations in the density of states are found which reveal that these CT complexes can work as molecular multi-vibrators.

IPC Code: Int. Cl.8 G01N21/35

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 348-352

 

Use of zirconium(IV) phosphate as a solid acid catalystin some esterification reactions

H K Patel, R S Joshi & U V Chudasama*

Received 8 January 2007; revised 31 January 2008

Amorphous and crystalline phases of zirconium(IV) phosphate of the class of tetravalent metal acid (TMA) salts have been synthesized by sol-gel method. The materials have been characterized for elemental analysis (ICP-AES), thermal analysis (TGA), X-ray analysis, BET surface area, surface acidity (NH3-TPD) and FTIR spectroscopy. Chemical resistivity of the materials has been accessed in acids, bases and organic solvent media. The exchangeable protons present in the structural hydroxyl groups indicate good potential for TMA salts to be investigated as solid acids. Esterification reaction has been selected as a model reaction to study the application of ZrP (amorphous and crystalline phases) as a solid acid. The catalytic activity explored by synthesizing monoesters and diesters reveals the promising use of ZrP as an ecofriendly solid acid catalyst.

IPC Code: Int. Cl.8 B01J21/00; B01J39/12

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 353-360

 

Synthesis, characterization and properties of some ternary copper(II) complexes containing NOS donor Schiff base and NN donor bidentate ligands

 

R N Patel*, V L N Gundla & D K Patel

Received 3 December 2007; revised 6 February 2008

Six ternary copper(II) complexes, viz., [Cu(SAT)(H2O)] (1), [Cu(SAT)(phen)].0.5 H2O (2), [Cu(SAT)(bipy)] (3), [Cu(SAA)(dmp)] (4), [Cu(SAT)(en)] (5) and [Cu(SAT)(temed)] (6), where SAT = Salicylideneaminothiophenol, phen = 1,10-phenanthroline, bipy = 2,2˘-bipyridyl, dmp = 2,9-dimethyl 1,10-phenanthroline, en = ethylenediamine, temed = N,N,N˘,N˘-tetramethylethylinediamine have been synthesized and characterized by various physico-chemical techniques. The metal ligand bonding parameters evaluated from the EPR spectra of the complexes indicate strong in-plane s and in-plane p bonding. The magnetic and spectroscopic data indicate a square planar geometry for complex 1 and a square pyramidal geometry for remaining complexes. The crystal structure of complex 2 has been determined by X-ray diffraction technique. The superoxide dismutase activity of the complexes has also been measured and discussed.

IPC Code: Int. Cl.8 CO7F1/08; CO7C251/02

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 361-368

 

Mixed-ligand hydrazonato-oxovanadium(V) complexes incorporating salicylaldehyde as co-ligand

Tapas Ghosh* & Bipul Mondal

Received 30 November 2007; revised 7 February 2008

[VIVO(acac)2] reacts with an equimolar amount of tridentate dibasic ONO donor hydrazone ligand derived from the condensation of benzoyl hydrazine with either 2-hydroxyacetophenone (H2L1) or its para-substituted derivatives (H2L2-4) (general abbreviation H2L), in the presence of excess amount of salicylaldehyde (Hsal) in methanol under aerobic conditions producing the mixed-ligand [VVO(L)(sal)], complexes (1)-(4) in good yields. The complexes are diamagnetic indicating the pentavalent state of vanadium and exhibit only LMCT transition band near 440 nm in addition to intra-ligand (π→π*) transition band near 330 nm in CH2Cl2 solution. IR spectra of these complexes in KBr disc and their 1H NMR spectra in CDCl3 solution indicate the presence of two isomeric forms for each of these complexes in different proportions. λmax (for the LMCT transition) and redox potentials of these complexes are linearly related to the Hammett constants (σ) of the substituents in the aryloxy ring of the hydrazone ligands.

IPC Code: Int. Cl.8 C07F9/00

 

Indian Journal of Chemistry

Vol. 47, March 2008, pp. 369-373

 

Proton transfer equilibria between disubstituted benzoic acids and carbinol base of crystal violet in apolar aprotic solvents. Chemometric analysis of disubstituent effects on the strength of benzoic acid in chlorobenzene

 

Susanta K Sen Gupta* & Ruchi Shrivastava

Received 12 April 2007; revised 11 February 2008

Proton transfer equilibria in chlorobenzene between a set of di-substituted (2,3-,2,5-,2,6-, 3,5-dichloro and difluoro) benzoic acids including the corresponding mono-substituted acids and the carbinol base of crystal violet have been studied spectrophotometrically. To investigate the effect of disubstitution at ortho- and/or meta- positions on the strength of benzoic acid, the results have been analysed chemometrically on the basis of Fujita Nishioka’s multiparameter approach and the assumption of additivity for substituent effects. The model employed explains 94% of the variance for the disubstituent effects on log K. It is observed that the substituent effect is contributed by ordinary electronic and proximity electronic effects in an almost equal ratio (52:48).

 

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 374-377

 

Synthesis and spectral characterization of Pb(II) perchlorate complexes

 

Salih İlhan

Received 14 June 2007; revised 28 January 2008

Five new types of Pb(II) perchlorate complexes have been synthesized by template effect by reaction of 2,6-diaminopyridine, Pb(ClO4)2.6H2O and dialdehydes in methanol. The complexes have been characterized by elemental analysis, IR spectra, UV-vis spectra, conductivity measurements and mass spectra. On the basis of spectral studies, five coordinated and square pyramid geometry may be assigned to these complexes.

IPC Code: Int. Cl.8 C07F7/00

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 378-382

 

Synthesis and characterization of macrocyclic Cd(II) complexes

 

Salih İlhan* & Hamdi Temel

Received 30 July 2007; revised 28 January 2008

Ten new Cd(II) complexes have been synthesized with Cd(ClO4)2.6H2O, Cd(NO3)2.6H2O in chloroform-methanol. The complexes have been characterized by elemental analysis, IR, 1H NMR, UV-vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. On the basis of the spectral studies, four-coordinated tetrahedral geometry may be assigned to these complexes.

IPC Code: Int. Cl.8 CO7F3/08

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 383-386

 

Electrochemical behaviour of 1, 3-diphenyl-3-hydroxytriazene and its copper complex

Manu Gupta, B S Bairwa, Romila Karnawat, I K Sharma & P S Verma*

Received 18 August 2007; revised 18 January 2008

1,3-Diphenyl-3-hydroxytriazene (DPHT) and its Cu complex have been synthesized and characterized by elemental analysis, IR, 1H NMR, 13C NMR spectra and magnetic susceptibility studies. DPHT acts as a bidentate ligand through N-hydroxy and triazeno groups and coordinates to the bivalent Cu metal ions. Cyclic voltammetry studies on glassy carbon electrode (GCE) as well as Pt electrode at various sweep rates and pH values reveal that DPHT shows six electrons irreversible reduction behaviour while its Cu complex undergoes one electron quasi-reversible electrode reaction. Electrochemical reduction of DPHT has been carried out at constant current using stainless steel (SS-316) electrodes yielding phenylhydrazine and aniline. The products have been isolated, purified and characterized by combined application of chromatographic and spectroscopic techniques. Mechanism for electro-reduction of DPHT in acidic, aqueous and alkaline medium has also been proposed.

IPC Code: Int. Cl. 8 G07f1/08; G01N27/00

 

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 387-389

 

Cyclohexylation of phenol over a solid acid catalyst comprising
12-tungstophosphoric acid and hydrous zirconia

Nikunj Bhatt & Anjali Patel*

Received 23 February 2007; revised 29 January 2008

The Friedel-Crafts alkylation (cyclohexylation of phenol with cyclohexene) has been carried out over 12-tungstophosphoric acid supported on hydrous zirconia under mild conditions. The catalyst shows high activity and selectivity for 2-cyclohexyl phenol, an important product used as intermediate in dyestuff preparation as well as in preparation of 2-phenyl phenol which is used as disinfectant and fungicide. In addition, the catalyst can be recycled and reused.

IPC Code: Int. Cl. 8 B01J21/06; B01J27/16

 

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 390-393

 

Proton transfer equilibria between o-substituted benzoic acids and the carbinol base of crystal violet in apolar aprotic solvents: Chemometric analysis of
ortho effect

 

Susanta K Sengupta* & Sangeeta Mishra

Received 27 November 2006; revised 16 January 2008

Toluene-phase reaction equilibria between a set of o-substituted benzoic acids and crystal violet carbinol base producing a coloured ion-pair have been studied spectrophoto-metrically at 28±1°C. Chemometric analysis on the basis of both Charton’s and Fujita-Nishioka’s multiparameter approaches for o-substituent effects on the equilibrium constants show that proximity electronic effect of an o-substituent is the main intrinsic contribution to the anomalous ortho effect with its steric factor contributing merely a minor effect. However, in the aqueous phase the steric contribution becomes significant due to hydration induced substantial enhancement in the bulk of the -COOH group and the o-substituent.

 

 

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 394-396

 

Vitamin K3 encapsulated poly(vinylpyrrolidone) film modified glassy carbon electrode for studying the vitamin K3 – caffeine interaction

Diganta Kumar Das* & Rimki Bhattacharjya

Received 5 March 2007; revised 24 January 2008

The cathodic and anodic peak currents in cyclic voltammogram of vitamin K3 encapsulated polyvinyl pyrollidone film modified glassy carbon electrode decrease with addition of caffeine (from 0.02 μM to 0.2 μM) in the electrolytic solution. Caffeine converts vitamin K3 into diphenylenetetranol, which is electrochemically inactive. This interaction between vitamin K3 and caffeine is not observed when both are in solution.

IPC Code: Int. Cl.8 G01N27/00

Indian Journal of Chemistry

Vol. 47A, March 2008, pp. 397-400

 

Photocatalytic degradation of sunset yellow FCF in presence of some transition metal complexes and hydrogen peroxide

Savitri Lodha, Abhilasha Jain, VK Sharma & Pinki B Punjabi*

Received 17 May 2007; revised 18 February 2008

The photocatalytic degradation of sunset yellow FCF by thiocyanate complexes of iron, copper and cobalt and hydrogen peroxide is reported here. The effect of different parameters, such as the pH, concentration of the complexes and dye, amount of H2O2 and light intensity on the rate of photocatalytic degradation has also been studied. The mechanism for degradation of the dye is also proposed.

IPC Code: B01J27/00; C02F1/72k