Indian Journal of Chemistry

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

 

VOLUME 46A

NUMBER 3

March 2007

 

CONTENTS

 

 

391

 

Theoretical studies on supramolecular complexes of anthyridone with various diaminopyridine derivatives

 

 

 

 

 

 

 

 

 

 

 

 

X Chen, Q Teng*, S Wu & L Xu

 

 

 

At the ground state, the complexes formed by anthyridone and 2,6-diaminopyridine-3,5-dialdehyde derivatives have been studied using the AM1 method to obtain information on their binding energies.

 

396

 

Ab initio and DFT investigation of electrophilic addition reaction of chlorine to endo,endo-tetracyclo[4.2.1.13,6.02,7]dodeca-4,9-diene

 

 

 

 

 

 

 

 

 

 

 

 

Rza Abbasoglu* & Yaprak Uygur

 

 

 

 

 

The electronic and geometric structures of endo,endo-tetracyclo[4.2.1.13,6.02,7] dodeca-4,9-diene(TTDD) molecule have been investigated by ab initio and DFT/B3LYP methods with the
6-31G* and 6-311G* basis sets. The double bonds of TTDD molecule have been endo-pyramidalized.

 

 

401

 

Reactions of pentapseudohalo nitrosyl iron with morpholinomethyl urea and related ligands

 

 

 

 

 

 

 

Sarika Anand

 

 

 

Na2[Fe(CN)5(NO)], Na[Fe(N3)5(NO)] and K2[Fe(CNO)5(NO)] react with morpholinomethyl urea and related ligands to form complexes of the type, [Fe(X)3(NO)(L-L)] where X = CN-, NCO- and N3- and L-L = morpholinomethyl urea, morpholinomethyl thiourea, piperidinomethyl urea and piperidinomethyl thiourea. The studies reveal that the complexes are non-electrolytic in nature and the ligands bind iron in a bidentate manner through carbonyl oxygen/thiocarbonyl sulphur and ring nitrogen of heterocyclic base. Molecular modeling suggests a distorted octahedral environment around iron.

 

 

407

 

Homogeneous catalysis of manganese(II) in the oxidation of citric acid by acid bromate: A novel kinetic behaviour of citric acid

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cherkupally Sanjeeva Reddy

 

 

 

The kinetic and mechanistic studies on Mn(II)-catalysed oxidation of citric acid by acid bromate in presence of Hg(II) as a scavenger are reported. The reaction exhibits 1.5 order each in [bromate] and [acid], and less than unit order in [Mn(II)].

 

 

416

 

The kinetic study on the effects of mixed aqueous-organic solvents on the rate of O- and N- cyclisation of N-(4nitrophenyl)phthalamic acid

 

 

 

 

 

 

 

 

 

 

 

 

Wan Hamdah Wan Ahmad, Azhar Ariffin &
M Niyaz Khan*

 

 

 

The pseudo-first-order rate constants (kobs) for the intra-
molecular carboxylic group-assisted cleavage of
N-(4
-nitrophenyl)phthalamic acid (1) show nonlinear decrease of ~ 17-fold and ~ 117-fold, with the increase in the respective contents of CH3CN (10-80% v/v) and 1,4-dioxan (9.5-79.4% v/v) in mixed aqueous solvents.

 

 

422

 

Synthesis, characterization and superoxide dismutase studies of square pyramidal copper(II) complexes with bi and tridentate polyamine ligands

 

 

 

 

 

 

 

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

 

 

 

Notes

 

428

 

Luminescent properties of blue phosphor Ba2CaB6O12:Eu2+ under vacuum-ultraviolet and ultraviolet excitation

 

 

Yucai Hu*, Ping Yin, Huirong Cheng , Huidi Yu, Hui Xu, Hong Liu & Jian Li

 

 

 

The luminescence of Eu2+ in Ba2CaB6O12 has been investigated under vacuum ultraviolet and ultraviolet excitation. The emission spectra of Eu2+ under vacuum ultraviolet and ultraviolet consist of two broad bands peaking at 445 and 465 nm, which are associated with the fd transitions of Eu2+ in the sites of Ba2+and Ca2+, respectively. Two weak peaks in vacuum ultraviolet range are observed at 160 nm and 200 nm.

 

432

 

Photocatalytic bleaching of Evans blue over zinc oxide particulate system

 

 

 

 

 

  

 

 

Sharad Kothari*, Preeti Ameta &
Rameshwar Ameta

 

 

 

Evans blue, an azo dye, and its mixture with amaranth are degraded photocatalytically in presence of zinc oxide. During the photocatalytic degradation, the semiconductor ZnO remains unaffected.

 

1 EB 0 1EB 1

1EB1 ISC 3EB 1

ZnO ZnO (h+) + ZnO (e-)

3 EB1 + ZnO EB+ ZnO (e-)

ZnO (e-) + O2 ZnO + O2-●

OH+ ZnO (h+) OH+ ZnO

3 EB + OH Products

 

436

 

Correlation analysis in the reactions of benzyl bromide with N-substituted anilines

 

 

 

 

 

 

 

 

  

 

 

S Ranga Reddy, B Rajeswara Rao &
P M
anikyamba*

 

 

 

The nucleophilic substitution reaction between benzyl bromide and N-substituted anilines in methanol medium suggests that the reactivity of the nucleophiles increases with their pkb values.

 

 

440

 

Synthesis of some Ni(II) complexes containing
4-substituted benzylidene (4-benzyloxy)benzoyl hydrazone ligand

 

 

 

 

 

  

 

 

M B H Howlader* & M S Islam

 

 

 

 

445

 

Kinetics and mechanism of the oxidation of some
a-hydroxy carboxylic acids by [bis(trifluoroacetoxy) iodo]benzene

 

 

Jayshree Banerji, Pradeep K Sharma* &
Kalyan K Banerji

 

 

 

 

 

449

 

Kinetics, thermodynamics and sorption characteristics of an inorganic ion exchanger, titanium phosphate, towards first row transition metal ions

 

 

 

Kalpana Maheria & Uma Chudasama*

 

 

 

Amorphous titanium phosphate, an inorganic ion exchanger of the class of tetravalent metal acid salt, has been synthesized by sol-gel method, and characterized. Chemical resistivity of the material has been assessed in various media, i.e., acids, bases and organic solvents. The Na+ ion exchange capacity has been determined and effect of heating on the ion exchange capacity has been studied. The sorption/ion exchange behaviour of the exchanger towards Cu(II), Mn(II), Ni(II) and Zn(II) has been studied. The selectivity order is found to be: Mn(II) > Ni(II) > Cu(II) > Zn(II).

 

 

455

 

Apparent molar volumes of oxalic acid in water and in aqueous solutions of fructose at 293.15, 303.15, 313.15 and 323.15K

 

 

 

  

 

 

Radha Rani Gupta & Mukhtar Singh*

 

 

 

Apparent molar volumes of oxalic acid in water and in aqueous solutions of fructose of varying concentrations have been determined as a function of molality. From these data, the limiting apparent molar volume, which is equal to the partial molar volume of oxalic acid at inifinite dilution, has been obtained at different temperatures. The partial molar volumes have been used to calculate the partial molar volumes of transfer of oxalic acid from water to aqueous fructose solutions. The values of limiting apparent molar expansibilities, and that of have also been determined. The results have been discussed in terms of various interactions operating in oxalic acid, water and fructose systems.

 

 

 

Authors for correspondence are indicated by (*)


Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 391-395

 

Theoretical studies on supramolecular complexes of anthyridone with various diaminopyridine derivatives

 

X Chen, Q Teng*, S Wu & L Xu

Received 17 April 2006; revised 2 February 2007

At the ground state, the complexes formed by anthyridone (A) and 2,6-diaminopyridine-3,5-dialdehyde (B) derivatives have been studied using the AM1 method to obtain information on the binding energies. The UV, IR and NMR spectra for the complexes have been calculated with the INDO/CIS, AM1 and B3LYP/6-31G methods, respectively. The results demonstrate that the complexes can be formed by the two monomers owing to the negative binding energy. The binding energy increases with the decrease in the intramolecular hydrogen bonds, but decreases with the increase in electron density on monomer B. The bulky group next to the hydrogen bond in monomer A is unfavorable, whereas the electron-donating group without the steric effect is favorable for formation of the hydrogen bonds. The first absorption in the UV spectrum of the complex is red-shifted relative to those of the two monomers. On formation of the hydrogen bonds the stretching vibrations of the N-H bonds are weakened and shift to lower frequencies in the IR spectra. In the NMR spectra, the chemical shifts move downfield.

 

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 396-400

 

Ab initio and DFT investigation of electrophilic addition reaction of chlorine to endo,endo-tetracyclo[4.2.1.13,6.02,7]dodeca-4,9-diene

Rza Abbasoglu* & Yaprak Uygur

Received 2 May 2006; revised 31 January 2007

The electronic and geometric structures of endo,endo-tetracyclo[4.2.1.13,6.02,7] dodeca-4,9-diene(TTDD) molecule have been investigated by ab initio and DFT/B3LYP methods with the 6-31G* and 6-311G* basis sets. The double bonds of TTDD molecule have been endo-pyramidalized. The structure of π-orbitals and their mutual interactions for TTDD molecule have been investigated. The cationic intermediates and products obtained as a result of the addition reaction have been studied using HF/6-311G*, HF/6-311G**, B3LYP/6-311G* and B3LYP/6-311++G**//B3LYP/6-311G* methods. The bridged chloronium cation isomerises into the more stable N- and U-type cations and the difference between the stability of these cations is little. The direction of the addition reaction has been determined by the direction of the rearrangement of the bridged chloronium ion into the N- and U-type cations. The N- and U-type reaction products are obtained as a result of the reaction, which takes place via the cations in question. The stability of exo,exo and exo,endo isomers of N-type product are nearly the same and the formation of both isomers is feasible. The U-type product is basically formed from exo,exo-isomer. Although, the U-type cation is 3.037 kcal mol-1 more stable than the N-type cation, the U-type product is 2.769 kcal/mol more unstable than the N-type product. The reaction products are controlled kinetically.

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 401-406

 

Reactions of pentapseudohalo nitrosyl iron with morpholinomethyl urea and related ligands

Sarika Anand

Received 19 October 2006; revised 18 December 2006

Na2[Fe(CN)5(NO)], Na[Fe(N3)5(NO)] and K2[Fe(CNO)5(NO)] react with morpholinomethyl urea and related ligands to form complexes of the type, [Fe(X)3(NO)(L-L)] where X = CN-, NCO- and N3- and L-L = morpholinomethyl urea (MMU), morpholinomethyl thiourea (MMTU), piperidinomethyl urea (PMU) and piperidinomethyl thiourea (PMTU). The complexes have been characterized by various physico-chemical techniques, viz., elemental analysis, molar conductance, magnetic susceptibility measurements, infrared spectroscopy, electronic spectra, thermal gravimetric analysis and molecular modeling. The studies reveal that the complexes are non-electrolytic in nature and the ligands (MMU, MMTU, PMU and PMTU) bind iron in a bidentate manner through carbonyl oxygen/thiocarbonyl sulphur and ring nitrogen of heterocyclic base. Molecular modeling suggests a distorted octahedral environment around iron.

IPC Code: Int. Cl.8 C07F15/02

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 407-415

 

Homogeneous catalysis of manganese(II) in the oxidation of citric acid by acid bromate: A novel kinetic behaviour of citric acid

Cherkupally Sanjeeva Reddy

Received 14 September 2006; revised 12 February 2007

The kinetic and mechanistic studies on Mn(II)-catalysed oxidation of citric acid by acid bromate in presence of Hg(II) as a scavenger have been carried out under varying conditions. The reaction exhibits 1.5 order each in [bromate] and [acid], and less than unit order in [Mn(II)]. The kinetic behaviour of citric acid is novel, being 0.30 order in the lower [citric acid] range and tending to 0.25 order at higher [citric acid]. Hg(OAc)2 and D2O have insignificant effect on the reaction rate. Formal redox potential for the Mn(II)/Mn(III)citric acid couple is determined as 0.32 V (vs SCE) and 0.58 V (vs NHE). These findings are accounted quantitatively by the formation of 1:1 (MnCt) and 1:2 (MnCt2) manganese(II)-citric acid complexes of which only 1:1 (MnCt) complex is kinetically active towards the bromate oxidation. In the envisaged mechanism, acid bromate reacts with the 1:1 (MnCt) complex, whose formation is precedent to the Mn(II)-Br(V) reaction. It results in an intermediate complex, which subsequently decomposes to the products. At higher [citric acid], the ratio of 1:2 and 1:1 Mn(II)-citric acid complexes reached 1.98. The effects of [pyrophosphate], [LiF], dielectric constant of the media and ionic strength are also in accordance with the proposed mechanism. Reaction constants involved in the proposed mechanism have been evaluated and thermodynamic parameters computed.

IPC Code: Int. Cl.8 B01J8/00; C07B33/00

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 416-421

 

The kinetic study on the effects of mixed aqueous-organic solvents on the rate of O- and N- cyclisation of N-(4-nitrophenyl)phthalamic acid

Wan Hamdah Wan Ahmad, Azhar Ariffin & M Niyaz Khan*

Received 4 December 2006; revised 30 January 2007

The pseudo-first-order rate constants (kobs) for the intramolecular carboxylic group-assisted cleavage of
N-(4-nitrophenyl)phthalamic acid (1) show nonlinear decrease of ~ 17-fold and ~ 117-fold with the increase in the respective contents of CH3CN (10-80% v/v) and 1,4-dioxan (9.5-79.4% v/v) in mixed aqueous solvents. The fraction of N-cyclization of 1 leading to the formation of N-(4-nitrophenyl)phthalimide, 2, remains almost zero at ≤40% v/v CH3CN while it increases from 0.06 to 0.49 with increase in CH3CN content (50-80% v/v) at 1.010-3 M HCl. However, the observed data reveal an almost absence of N-cyclization within 1,4-dioxan content range 10-80% v/v.

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 422-427

 

Synthesis, characterization and superoxide dismutase studies of square pyramidal copper(II) complexes with bi and tridentate polyamine ligands

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

Received 5 July 2006; revised 25 January 2007

Ternary copper(II) complexes containing bi and tridentate polyamine ligands, viz. [Cu(dien)(en)](ClO4)2 (1), [Cu(dien)(temed)](ClO4)2 (2) and [Cu(pmdt)(temed)](ClO4)2 (3) where dien = diethylenetriamine, en = ethylenediamine, temed = N,N,N,N-tetramethylethylenediamine and pmdt = N,N,N,N,N-pentamethyldiethylenetriamine have been synthesized and characterized by elemental analysis, magnetic susceptibility, X-band EPR spectroscopy and electronic spectroscopy. Single crystal X-ray of complex (1) reveals the presence of a distorted square pyramidal geometry in the complex. The complex (1) crystallizes in the monoclinic space group P21/n with unit cell parameters a = 8.4014(10) , b = 14.474(3) and c = 12.935 (2) . Complex 1 has a five coordinate (4+1) geometry with a CuN5 core. Magnetic susceptibility and electron paramagnetic resonance (EPR) behaviour of these complexes show their paramagnetic nature (3d9 Cu2+, S = ). Superoxide dismutase activity of these complexes has also been measured.

IPC Code: Int. Cl.8 C07F1/08

 

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 428-431

 

Luminescent properties of blue phosphor Ba2CaB6O12:Eu2+ under vacuum-ultraviolet and ultraviolet excitation

 

Yucai Hu*, Ping Yin, Huirong Cheng, Huidi Yu, Hui Xu, Hong Liu & Jian Li

Received 19 October 2006; revised 16 January 2007

The luminescence of Eu2+ in Ba2CaB6O12 has been investigated under vacuum ultraviolet and ultraviolet excitation. Two different crystallographic sites are available for Eu2+ in Ba2CaB6O12. In this structure, there are linear rows of three cations in the order of Ba2+, Ca2+ and Ba2+, Ca2+ being in the central position. The emission spectra of Eu2+ under vacuum ultraviolet and ultraviolet consist of two broad bands peaking at 445 and 465 nm, which are associated with the fd transitions of Eu2+ in the sites of Ba2+and Ca2+, respectively. Two weak peaks in vacuum ultraviolet range are observed at 160 nm and 200 nm.

 

IPC Code: Int. Cl.8 C09K11/00; G01N21/64

 

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 432-435

 

Photocatalytic bleaching of Evans blue over zinc oxide particulate system

Sharad Kothari*, Preeti Ameta & Rameshwar Ameta

Received 10 May 2006; revised 31 January 2007

Evans blue, an azo dye, and its mixture with amaranth are degraded photocatalytically in presence of zinc oxide. The optimum conditions for photobleaching of these dyes, like concentration of dye, pH, amount of semiconductor, light intensity, etc., have been studied. During the photocatalytic degradation, the semiconductor (ZnO) remains unaffected as evident from its FT-IR. The studied dyes are commonly used in dyeing, printing and textile industries and hence, the present work will be helpful in the treatment of coloured effluents from these industries.

IPC Code: Int. Cl. 8 B01J8/00

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 436-439

 

Correlation analysis in the reactions of benzyl bromide with N-substituted anilines

 

S Ranga Reddy, B Rajeswara Rao# & P Manikyamba*

Received 8 September 2006; revised 5 February 2007

The nucleophilic substitution reaction between benzyl bromide and N-substituted anilines in methanol medium suggests that the reactivity of the nucleophiles increases with their pkb values. A linear relationship exists between the rate and the computed values of the dipole moment and electronegativity of the nucleophiles. The frontier orbital interactions and correlation of rate with HOMO-LUMO gap of the two reactants suggest that the reaction is not orbital controlled but is controlled by the electrostatic interactions between the reactants.

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 440-444

 

Synthesis of some Ni(II) complexes containing 4-substituted benzylidene (4-benzyloxy)benzoylhydrazone ligand

M B H Howlader* & M S Islam

Received 10 August 2006; revised 4 February 2007

Reaction of the ligand precursor, 4-benzyl-oxybenzoylhydrazine (1) with benzaldehyde and substituted benzaldehydes (e.g., 4-methoxybenzaldehyde, 4-chlorobenzaldehyde, 4-bromobenzaldehyde, 4-nitrobenzaldehyde, 4-methyl-benzaldehyde, 4-ethylbenzaldehyde) with nickel(II) acetate yields the complexes bis[N-4-substituted benzylidene(4-benzyloxy) benzoyl-hydrazinato]nickel(II) 3-9, respectively. The complexation proceeds via the intermediate ligand formation (2), not the template method. Complexes having the electron withdrawing groups of the benzylidene moiety (=CHC6H4X) are more soluble than having the electron donation groups. Among the compounds, only 3, 4 and 8-11 show activity against the pathogenic bacteria (E. coli, S. dysentria, B. subtilies, St.b-haemolytica), while other compounds 5-7 and 12 do not show any activity. The electron donating group (X = H, OCH3, CH3, C2H5) of the benzylidene moiety (=CHC6H4X) may be responsible for the activity of the compounds.

IPC Code: Int. Cl.8 C07F15/04

 

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 445-448

 

Kinetics and mechanism of the oxidation of some a-hydroxy carboxylic acids by [bis(trifluoroacetoxy)iodo]benzene

Jayshree Banerji, Pradeep K Sharma* & Kalyan K Banerji

Received 20 October 2006; revised 25 January 2007

The oxidation of a-hydroxy carboxylic acids by [bis(trifluoroacetoxy)iodo]benzene (TFAIB), to the corresponding oxoacids is first order with respect to each, the hydroxy acid, TFAIB and hydrogen ions. The oxidation of a-deuteriomandelic acid (PhCDOHCO2H) exhibits the presence of a substantial primary isotope effect confirming the cleavage of the a C H bond in the rate-determining step. The rate of oxidation of substituted mandelic acids correlates well with Browns s+ values with large negative reaction constants. A mechanism involving transfer of a hydride ion from the hydroxy acid to the oxidant has been postulated.

IPC Code: Int. Cl.8 C07B33/00

 

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 449-454

 

Kinetics, thermodynamics and sorption characteristics of an inorganic ion exchanger, titanium phosphate, towards first row transition metal ions

Kalpana Maheria & Uma Chudasama*

Received 19 July 2006, revised 8 February 2007

Amorphous titanium phosphate, an inorganic ion exchanger of the class of tetravalent metal acid salt, has been synthesized by sol-gel method, and characterized for elemental analysis (ICP-AES), spectral analysis (FT-IR), thermal analysis (TGA, DTA, DSC) and X-ray diffraction studies. Chemical resistivity of the material has been assessed in various media, i.e., acids, bases and organic solvents. The Na + ion exchange capacity has been determined and effect of heating on the ion exchange capacity has been studied. The sorption/ion exchange behaviour of the exchanger towards Cu(II), Mn(II), Ni(II) and Zn(II) has been studied at different temperatures (313 K, 323 K and 333 K). Kinetic and thermodynamic parameters have been evaluated and adsorption isotherms have been studied. Based on the above studies the selectivity order is found to be: Mn(II) > Ni(II) > Cu(II) > Zn(II).

IPC Code: Int. Cl.8 B01J39/02

 

Indian Journal of Chemistry

Vol. 46A, March 2007, pp. 455-458

 

Apparent molar volumes of oxalic acid in water and in aqueous solutions of fructose at 293.15, 303.15, 313.15 and 323.15K

Radha Rani Gupta & Mukhtar Singh*

Received 6 June 2006; rerevised 22 January 2007

Apparent molar volumes (Vf) of oxalic acid in water and in aqueous solutions of fructose of varing concentrations (0.5-2.6) mol kg-1 have been determined as a function of molality by measuring the densities at 293.15, 303.15, 313.15 and 323.15K. From these data, the limiting apparent molar volume , which is equal to the partial molar volume of oxalic acid at inifinite dilution (), has been obtained at different temperatures. The partial molar volumes have been used to calculate the partial molar volumes of transfer () of oxalic acid from water to aqueous fructose solutions. The values of limiting apparent molar expansibilities, () and that of have also been determined from temperature-dependence of at various concentrations of the fructose solutions. The results have been discussed in terms of various interactions operating in oxalic acid, water and fructose systems.