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Indian Journal of Chemistry

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

 

 

VOLUME 42A

NUMBER 7

JULY 2003

 

CONTENTS

Papers

1557

Quantum chemical investigation of molecular complexes formed with bromine molecule of bicyclo[3.3.1] nonylidenebicyclo[3.3.1] nonane and its derivatives

 

 

 

 

 

R Abbasoğlu*  & S Savaşkan Yilmaz

 

 

1564

Simulation of the infrared spectra of
N-methylformamide and N-methylacetamide by the extended molecular mechanics method

 

 

 

 

D N Sathyanarayana* & E Ganeshsrinivas

 

The infrared spectra of the matrix isolated species of
N-methylformamide (NMF) and N-methylacetamide (NMA) and their N-deuterated isotopic species have been simulated by the extended molecular mechanics method using an empirical force field which includes charges and charge fluxes as coulombic potential parameters.

1575

On the electronic structures and conduction properties of quasi-one-dimensional copolymers (type-II staggered) of donor-acceptor polymers

 

 

 

 

Geetika Gandhi & A K Bakhshi*

 

The electronic structures and conduction properties
of various periodic and aperiodic copolymers (AmBn)x of two novel donor-acceptor polymers, PPDCH [A]x and
PPDCN [B]x have been investigated using negative factor counting method based on Dean’s negative eigen value theorem.

1581

Cu-substituted MnCuxAl 2-xO4: A new catalyst for NO reduction and oxidation of CO, NH3, CH4 and C3H8

 

 

 

 

A S Prakash, Parthasarathi Bera, A M A Khadar & M S Hegde*

 

Cu-substituted MnCuxAl 2-xO4 spinels synthesized by the novel solution combustion method catalyse the oxidation of CO, NH3, CH4 and C3H8 and reduction of NO. High catalytic activity is attributed to the occurrence of both Cu2+ - Cu0 and Mn2+-Mn3+ redox couples created due to unique substitution of Cu2+ ion in Al3+ sites of this new material.

1590

IR, EPR and magnetic susceptibility studies on xCuO-0.45B2O3-(0.55-x)As2O3 polycrystalline systems

 

 

 

 

B B Das* & S Aruna

 

The structure and structure-property relationship of binary and ternary CuO-B2O3-As2O3 polycrystalline systems based on IR, EPR and magnetic susceptibility studies are reported.

1597

Hydrides of TbM2 ( M = Fe and Mn )

 

 

 

 

 

S K Kulshreshtha*, R Sasikala &
O D Jayakumar

 

Isostructural intermetallics, TbFe2, TbFeMn and TbMn2, having C-15 cubic Laves phase structure have been prepared. The hydriding characteristics of these intermetallics  and the effect of replacement of Fe by Mn on the crystallographic and magnetic characteristics of these hydrided samples have been studied using Mössbauer effect and powder X-ray diffraction techniques.

1604

Mössbauer, EPR, magnetic properties and thermally induced stereochemical studies on some double complex salts of cyclic ligand containing cationic copper(II) complexes and hexacyanoferrate(III) anion in the solid state

 

 

 

 

 

 

Parimal Kundu, Subrata Kumar Dey, Chirantan Roy Choudhury, Dilip Banerjee, Sanjoy Kumar, Ranga Lal Bhattacharya & Samiran Mitra*

 

 

1609

Coordination of isoniazid, an anti-tuberculosis (TB) drug with chromium, molybdenum, and tungsten metal carbonyls

 

 

 

 

 

 

 

D Jesudurai & S Vancheesan*

 

1617

Studies on synthesis, characterisation, molecular modeling and antimicrobial activity of some metal chelates of pyrazolone based ligands

 

 

 

 

 

M Alaudeen*, P G Sushama &
A Mary Dorothy

 

Some novel complexes of the ligands N-(3-methyl 1-thiocarbamyl-5-oxo-2-pyrazolin-4-ylene)-N'-(4'-antipyrine) hydrazine and N-(3-methyl-1-thiocarbamyl-5-oxo-2-pyrazolin-4-ylene)-N'-(4'-benzothiazole) hydrazine with Mn(III), Cr(III), Fe(III), Co(III), Zn(II) and Cd(II) have been prepared and characterised by elemental analysis, molar conductance values, magnetic susceptibility measurements and various spectral studies.

Notes

1622

On the reaction mechanism of some sulphur containing molecules: A theoretical study

 

 

 

 

 

 

B R De*, M Maity, S Mahato & K Saw

 

1627

Photodegradation of surfactants on the dye modified TiO2 surface using visible light

 

 

 

 

Debabrata Chatterjee* & Anima Mahata

 

Degradation of cationic, anionic and neutral surfactants on the surface of dye-modified TiO2 has been carried out. Mechanism involving excitation of surface adsorbed dye, followed by charge injection into the TiO2 conduction band and formation of reactive .OH radicals is proposed.

1632

Potentiometric studies on the stability constants of some a-amino acid –copper(II) and nickel(II) systems in ethanol-water mixture

 

 

 

Alev Doğan* & Esma Kiliç

 

The stability constants for the nickel(II) and copper(II)-a-amino acid binary complex systems are reported in
40% ethanol -60% water mixture. The stability of
the nickel(II) complexes is lower than that of the copper(II) complexes.

1636

Kinetic investigation of the oxidation of sulphanilic acid by peroxomonophosphoric acid in anionic surfactant sodium lauryl sulphate

 

 

 

Jagannath Panda & G P Panigrahi*

 

SAw  +  H3PO5(W)       Product

 

Ks             Ko

SAm  +  H3PO5(m)       Product

1639

Kinetics and mechanism of the oxidation of cobalt(II) aminopolycarboxylate complex by periodate ion in aqueous medium

 

 

 

 

 

Joy Sarkar, D D Chaturvedi, Amit K Verma, S K Singh & R M Naik*

 

 [L CoII - OIO3]1-n     [L CoIII - OIO3]1-n

 [L CoII - (OIO3)2] - n  [L CoIII - (OIO3)2] – n

 

1644

Kinetics and mechanism of C16TAB catalyzed oxidation of methylene violet  by chloramine –T in acidic medium

 

 

V W Bhagwat, Mona Pipada, S B Jonnalagadda & Brijesh Pare*

 

n  C16TAB      ®   (C16TAB)n

*MV+  + (C16TAB)n          ®   MV+…(C16TAB)n

MV+ …(C16TAB)n + HOCl  ®X1+

X1+  +HOCl    ® P1+ + CH3CN + 2 HCl

fast

P1+  +2 HOCl +  2 H2O ® P+ +  2 CH3CH2OH + 2 HCl

1649

Kinetics and mechanism of oxidation of hippuric acid with Bi (V) in phosphoric acid medium

 

 

 

 

P M Mishra, A K Jha & C S Jha*

 

K1

S   +   H+    Û    SH+

K2

SH+    +     Bi(V)    Û    Complex

k3

Complex à Product

1652

Synthesis of bis(tri-n-butyltin) esters of dicarboxylice acid and crystal structure of the three-dimensional framework of organotin polymer, bis (tri-n-butyltin) ester of succinic acid

 

 

 

Handong Yin*, Chuanhua Wang &
Chunlin Ma

 

1656

Synthesis and characterization of diorganotin esters of heteroaromatic carboxylic acid and crystal structure of nBu2Sn(2-PyCO2) 2.H2O

 

 

 

 

 

 

 

 

 

 

Handong Yin*, Chuanhua Wang, Yong Wang & Chunlin Ma

 

 

 

1661

 

Synthesis and characterization of some new heterochelates of chromium(III)

 

 

 

 

 

 

Kamalendu Dey*, Bijali Bikash Bhaumik, Susobhan Biswas & Saikat Sarkar

 

 

 

Heterochelates of chromium(III) have been prepared by the reactions of different mixed ligand complexes of chromium(III) with different monobasic bidentate ligands (L-L) and characterized.

 

1666

Molecular complexes of paraquat and chloranil with phenylhydrazones

 

 

 

 T Charan Singh, P Venkateshwar Rao,  T Veeraiah & G Venkateshwarlu*

 

 

1671

Ligand exchange reactions of sodium nitroprusside in the presence of sulphate ion under photochemical conditions

 

 

Mayank R Mehta, Piyush J Vyas,
Jitendra Vardia & Suresh C Ameta*

 

hn

Na2 [Fe(CN)5NO]      →    Na2[Fe(CN)5NO]*

hn

Na2[Fe(CN)5NO]*  +   H2O        Na3[Fe(CN)5(H2O)] + NO+

Na3[Fe(CN)5(H2O)]  + SO42-   →    Na5[Fe(CN)5(SO4)] + H2O

Na5[Fe(CN)5(SO4)]  +  SO42-   →   Na6[Fe(CN)4(SO4)2] +  CN-

 

1674

Solvent extraction of zinc(II), cadmium(II), mercury(II) and bismuth(III) using
n-octylaniline and their separations

 

 

 

 

S R Kuchekar,  H R Aher & M B Chavan*

 

 

Solvent extraction behaviour of zinc (II), cadmium (II), mercury (II) and bismuth (III) with n-octylaniline in different organic solvents from various aqueous acid solutions is reported.

 

Authors for correspondence are indicated by (*)

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1557-1563

 

 

Quantum chemical investigation of molecular complexes
formed with bromine molecule of bicyclo[3.3.1] nonylidenebicyclo[3.3.1] nonane and its derivatives

R Abbasoğlu* & S Savaşkan Yilmaz

 

The strain energies and the pyramidalization parameters of bicyclo [3.3.1]nonylydenebicyclo[3.3.1]nonane(BBN), trans-(1-methyl-2-bicyclo[3.3.1]-1-methyl bicyclo [3.3.1]nonane (DMBBN) and trans-(1-tert-butyl-2-bicyclo[3.3.1])-1-tert-butylbicyclo [3.3.1] nonane (DBBBN) molecules have been calculated using MM2 and AMBER molecular mechanic methods. The strain energy and the pyramidalization degree of the molecule are increased by increasing the volume of R groups at the allylic position of the double bond. The electronic structure of the molecules have been investigated by semiempirical PM3 method. The results of molecular mechanic and PM3 methods, agree with the X-ray results and shows that the double bond of BBN molecule has a planar structure. The 1:1 -molecular complexes of the molecules formed with Br2 are investigated using PM3 method and it is seen that their stable configuration has an axial structure. The electronic and the steric factors affecting the structure and the stability of the molecular complexes have been studied. It is found that the DMBBN...Br2 complex is more stable than the BBN...Br2 complex. It is determined that DBBBN...Br2 complex containing the bulky tert-butyl group has the lowest stabilization energy among the investigated molecular complexes.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1564-1574

 

 

Simulation of the infrared spectra of
N-methylformamide and N-methylacetamide
by the extended molecular mechanics method

D N Sathyanarayana* & E Ganeshsrinivas

 

The infrared spectra of the matrix isolated species of N-methylformamide (NMF) and N-methylacetamide (NMA) and their N-deuterated molecules have been simulated by the extended molecular mechanics method using an empirical force field which includes charges and charge fluxes as coulombic potential parameters. The structural parameters and dipole moments of NMF and NMA have also been computed in satisfactory agreement with the experiment. Good agreement between experimental and calculated vibrational frequencies and infrared absorption band intensities for NMF and NMA and their deuterated molecules has been obtained. The vibrational assignments of NMF and NMA are discussed taking also into account the infrared absorption intensities.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1575-1580

 

 

On the electronic structures and conduction properties of
quasi-one-dimensional copolymers (type-II staggered)
of donor-acceptor polymers

Geetika Gandhia & A K Bakhshib*

 

Using ab-initio band structure results of two novel donor-acceptor polymers PPDCH [A]x and PPDCN [B]x as the input, the electronic structures and conduction properties of their various periodic and aperiodic copolymers (AmBn)x have been investigated using negative factor counting method based on Dean’s negative eigen value theorem. These polymers consist of a bicyclopentadienylene unit bridged by an electron accepting group Y (where Y= in PPDCH and in PPDCN) as the repeat unit. The copolymers, on the basis of the band alignments of the two constituent homopolymers, are found to belong to the class of type-II staggered superlattices. The trends in their electronic structures and conduction properties as a function of (i) composition (m/n), (ii) block sizes m and n and (iii) arrangement of the blocks (periodic or aperiodic) in the various copolymer chains are discussed. The trends are important guidelines for designing novel electrically conducting copolymers.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1581-1589

 

 

Cu-substituted MnCuxAl2-xO4: A new catalyst for NO
reduction and oxidation of CO, NH3, CH4 and C3H8

A S Prakasha, Parthasarathi Beraa, A M A Khadarb & M S Hegdea*

 

Cu-substituted MnCuxAl2-xO4, (x = 0-1) spinels synthesized by the solution combustion method catalyse the oxidation of CO, NH3 and hydrocarbons and the reduction of NO. The catalytic activity varies with the composition and the oxide with x = 0.75 exhibits the highest catalytic activity. However, the catalyst with x = 0.5 shows the highest N2-selectivity of 80% up to 700C for ammonia oxidation. Selective catalytic reduction (SCR) of NO by NH3 in the presence of excess O2 over x = 0.75 catalyst shows over 70% N2-selectivity above 300C. Spinel structure of the catalyst is retained after the reactions. Hydrogen uptake studies show that at  300C oxygen storage capacity is over 110 ml/g, which corresponds to about 20% of the lattice oxygen. High catalytic activity is attributed to the occurrence of both Cu2+-Cu0 and Mn2+-Mn3+ redox couples created due to unique substitution of Cu2+ ion in Al3+ sites of this new material.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1590-1596

 

 

IR, EPR and magnetic susceptibility studies on
xCuO-0.45B2O3-(0.55-x)As2O3 polycrystalline systems

B B Das* & S Aruna

 

The XRD studies on xCuO-0.45B2O3-(0.55-x)As2O3 polycrystalline system reveal that for 0.05 ≤ x ≤ 0.30 the average particle sizes are in the range 192-249 Å. The density values do not follow any regularity with mol% CuO. The chemical analysis results show the formation of Cu1+ by reduction of Cu2+ in the matrix. The room temperature IR studies indicate the presence of Cu─O bond, planar [BO3/2] and tetrahedral [OAsO3/2] units in the matrix. Presence of B─O─B linkage is also identified at lower mol% As2O3. DTA/TG result shows no characteristic structural phase transformation in the range room temperature to 900°C. The fairly low values of the small polaron radii indicate that the polaron is slightly localized on a particular site. The very low values of the magnetic susceptibility suggest weak paramagnetic behaviour of the specimens. The values of the exchange integrals of the small polaron are found to be fairly low. The values of the g- and A-matrices are found to be similar within the composition range studied, at 300 K and at 77 K, and also do not change significantly in the range 300-77 K. This result shows that the [O1/2-CuO4/2-O1/2] octahedra containing the paramagnetic site Cu2+ is not affected significantly with the change in composition as well as with temperature in the range 300-77 K. The EPR lineshape simulation of specimen S1 at 77 K reveal that the paramagnetic Cu2+ ion is in a tetragonally distorted octahedron of six oxygen atoms, [O1/2-CuO4/2-O1/2], having D4h symmetry. There is significant out-of-plane π-bonding present in the octahedron, as a result, the square planar [CuO4/2] unit of the octahedron is highly “squeezed”.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1597-1603

 

 

Hydrides of TbM2 (M = Fe and Mn)

S K Kulshreshtha*, R Sasikala & O D Jayakumar

 

Intermetallics TbFe2, TbFeMn and TbMn2 having C-15 cubic Laves phase structure, have been prepared and hydrided to varying values of H/M using gas phase method up to a saturation composition of H/M  1.6. TbFe2Hx samples show the formation of a metastable rhombohedral phase for higher values of x, which on equilibration with hydrogen transforms to cubic form. Unlike this, TbFeMn shows the existence of both hydrided and unhydrided phases for x  3.0 and for higher values of x, uniform hydriding takes place and a saturation composition of TbFeMnH4.8 which is characterized by cubic structure with ‘a’ = 8.137Å, is obtained. For TbMn2Hx, for x  1.2, the formation of a tetragonal phase is observed. Mössbauer study of TbFe2Hx samples reveals that for TbFe2, the Fe spins are aligned along (111) direction, which on hydriding become non-collinear and shift towards (100) direction for TbFe2H3.15 composition. Mössbauer spectra of TbFeMn are complex and suggest a non-collinear spin alignment due to the existence of both ferromagnetic and antiferromagnetic interactions between transition metal elements and show a systematic decrease in magnetic field and magnetic transition temperature due to hydrogen incorporation in the matrix. Temperature programmed hydrogen desorption studies of TbFe2Hx and TbFeMnHx samples exhibit broad peaks in the region 225-350C, due to overlap effects and peak maxima shift slightly towards higher temperature side with Mn substitution. Unlike this, TbMn2Hx samples exhibit much better resolved TPR curves consisting of mainly three peaks placed over the region 275-400C, possibly because of the tetragonal structure of these samples.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1604-1608

 

 

Mössbauer, EPR, magnetic properties and thermally induced stereochemical studies on some double complex salts of
cyclic ligand containing cationic copper(II) complexes and hexacyanoferrate(III) anion in the solid state

Parimal Kundua, Subrata Kumar Deyb, Chirantan Roy Choudhuryb, Dilip Banerjeec, Sanjoy Kumarc,

Ranga Lal Bhattacharya & Samiran Mitra*b

 

Novel cyanide-bridged double complex salts of cationic copper(II) salts with cyclic ligand, viz., morpholine (Morph), N-methyl morpholine (Me-Morph) and homopiperazine (Hpz) and hexacyanoferrate(III) ion have been synthesized and characterized. Mössbauer spectra of the complexes have been recorded at 80 K and 300 K to investigate the metal-metal charge transfer and the impact of cyclic ligand present in the cationic part of the double complex salt on the Mössbauer spectra of hexacyanoferrate(III) ion. Metal-metal charge transfer transition has been supported by electronic spectra and magnetic susceptibility values. Variable temperature EPR spectra have been recorded to study the distortion of crystal systems. Activation energy and inception temperature for the thermochemical reactions show that the order of stability of the double complex salts follows the trend, Hpz>Me-Morph>Morph.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1609-1616

 

 

Coordination of isoniazid, an anti-tuberculosis (TB) drug with chromium, molybdenum, and tungsten metal carbonyls

D Jesudurai & S Vancheesan*

 

Isoniazid, an anti-tuberculosis (TB) drug has been coordinated with chromium, molybdenum, and tungsten metal carbonyls and three new zero-valent complexes fac-[M(CO)3(isoniazid)3] (M = Cr, Mo, and W; 4, 5, and 6) (isoniazid = 4-H2NHNOCC5H4N) have been synthesized. Reaction of the complex precursors fac-[M(CO)3(CH3CN)3] (M = Cr, Mo, and W; 1, 2, and 3) prepared ‘in situ’ with three equivalents of isoniazid in methanol at room temperature afforded high yields of isoniazid substituted metal carbonyl complexes 4, 5, and 6. The complexes have been characterized by elemental analyses, mass analysis, thermal analysis (TGA, EGA), FT-IR, UV/visible and 1H NMR spectroscopic techniques and powder X-ray diffraction (XRD). The FT-IR (KBr and methanol solution) spectra of the complexes 4, 5, and 6 exhibit two bands corresponding to (CO) of metal carbonyl groups and (C=O) of coordinated isoniazid molecules. The bulky –CONHNH2 group of isoniazid molecules made more impact on the MC bond strength of metal carbonyls and affects their fundamental modes of vibrations leading to the appearance of more number of (CO) bands. These steric effects are also reflected in the 1H NMR spectral features of the complexes when considering the complexes as a whole, wherein the four protons on the pyridine ring of the coordinated isoniazid molecules resonate at different chemical shifts. All the three complexes exhibit similar XRD pattern suggesting similar geometry.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1617-1621

 

 

Studies on synthesis, characterisation,
molecular modeling and antimicrobial activity of
some metal chelates of pyrazolone based ligands

M Alaudeen*, P G Sushama & A Mary Dorothy

 

Some novel complexes of the ligands N-(3-methyl 1-thiocarbamyl-5-oxo-2-pyrazolin-4-ylene)-N-(4-antipyrine) hydrazine (HATP) and N-(3-methyl-1-thiocarbamyl-5-oxo-2-pyrazolin-4-ylene)-N|-(4|-benzothiazole) hydrazine (HBTP) with Mn(III), Cr(III), Fe(III), Co(III), Zn(II) and Cd(II) have been prepared and characterised by elemental analysis, molar conductance values, magnetic susceptibility measurements and various spectral studies. The chemical studies and spectral data indicate that HATP and HBTP are in the hydrazone form. All complexes are six coordinates with Oh or D4h symmetry. Fe(III), Mn(III) and Cr(III) complexes are of high spin while Co(III), Zn(II) and Cd(II) chelates are diamagnetic. Molecular mechanics calculations also confirm the complexation behaviour of the ligands. HATP is neutral tetradentate towards Zn(II) and Cd(II) whereas tridentate with Co(III) and Mn(III) having compositions [M(HATP)X2] and [M|(HATP)X3] for M=Zn(II) and Cd(II) and M|=Mn(III) and Co(III) and X=Cl, OAc and NO3. HBTP is neutral tridentate towards all the metals with composition [M(HBTP)(H2O)X2] and [M1(HBTP)X3] where M=Cd(II) and Zn(II), M1=Fe(III) and Cr(III) and X=Cl, OAc and NO3. Ligands and complexes have been screened for their antibacterial activity against gram-positive and gram-negative bacteria.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1622-1626

 

 

On the reaction mechanism of some sulphur
containing molecules: A theoretical study

B R De*, M Maity, S Mahato & K Saw

 

Quantum mechanical study of gas phase reactions of hydrogen sulphide with chlorine and sulphur dioxide and sulphur monochloride with chlorine has been carried out by AM1 method with complete geometry optimization of the species. After construction of the potential energy surfaces, the energetically favourable reaction paths have been characterised. In all the three reactions it is found that the gas phase reaction proceeds through closed structure intermediate. The results are in agreement with experiment.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1627-1631

 

 

Photodegradation of surfactants on the dye
modified TiO2 surface using visible light

Debabrata Chatterjee* & Anima Mahata

 

Degradation of cationic CPC (cetyl pyridinium chloride), anionic DBS (sodium dodecylbenzene sulfonate) and neutral Triton-X 100 (octylphenyl polyoxyethylene ether) surfactants in air-equilibrated aqueous mixtures has been achieved on the surface of TiO2 semiconductor modified with Thionine, Eosin Y and Nile blue A by using visible light. Under 8 hr of irradiation with a 50W tungsten lamp, over 45-65% degradation of surfactants has been observed. A working mechanism involving excitation of surface adsorbed dye, followed by charge injection into the TiO2 conduction band and formation of reactive •OH radicals is proposed.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1632-1635

 

 

Potentiometric studies on the stability constants of
some -amino acid-copper(II) and nickel(II)
systems in ethanol-water mixture

Alev Doğan* & Esma Kılıç

 

The stability constants for the nickel(II) and copper(II)--amino acid (glycine, L-alanine, L-valine, L-leucine, L-isoleucine, L-serine, L-phenylalanine and L-methionine) binary complex systems have been studied using pH-measurements in 40% ethanol-60% water mixture. The study shows that at 25C and ionic strength at 0.10 M the following species are present in this solvent mixture: CuHL2+, CuL+, CuL2 for copper(II) complexes and NiL+, NiL2, NiL3 for nickel(II) complexes. The stability of the nickel(II) complexes is lower than that of the copper(II) complexes. The study shows that the tendency of -amino acids to form complexes with metal(II) ions is greater in 40% ethanol-60% water mixture as compared to that in only water.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1636-1638

 

 

Kinetic investigation of the oxidation of
sulphanilic acid by peroxomonophosphoric acid in
anionic surfactant sodium lauryl sulphate

Jagannath Panda & G P Panigrahi*

 

Oxidation of sulphanilic acid by peroxomonophosphoric acid (PMPA) in sulphuric acid medium is catalysed marginally in the presence of SLS. The rate reaches a maximum and then decreases. The oxidation rate-[micelle] profile is rationalised by Berezin model and binding constants of both the reactants with the micelle have been computed using the model.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1639-1643

 

 

Kinetics and mechanism of the oxidation of cobalt (II) aminopolycarboxylate complex by periodate ion in
aqueous medium

Joy Sarkara, D D Chaturvedia, Amit K Vermaa, S K Singhb & R M Naika*

 

The kinetics of reaction between [CoIIL2-n ] [L = 1,3, diamino-2-hydroxy propane tetraacetic acid (HPDTA) and propylenediamine tetraacetic acid (PDTA) ] and periodate ion has been studied spectrophotometrically at max = 550 nm under pseudo-first order conditions by taking large excess of periodate in acidic medium at pH = 4.0  0.02, I = 0.1 mol dm-3 (CH3COONa + NaNO3) and temp = 30  0.1oC. Experimental obervations revealed that a long lived intermediate is formed during the course of reaction which is converted to the corresponding [CoIII L3-n ] complex. The above reactions are found to obey the general rate law, rate = (k2 [IO4-] + k3 [IO42-]) [CoIIL2-n ]. A four step mechanistic scheme involving electron transfer through inner sphere complex formation has been proposed. Activation parameters have been evaluated from Arrhenius and Eyring’s equations. The values of activation parameters for [CoII PDTA]2 - and IO4- are H# = 47.65 kJ mol-1, S# = -259.41 JK-1 mol-1 and for [CoII HPDTA]2- and IO4- they are H# = 13.46 kJ mol-1, S# = -252.56 JK-1 mol-1.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1644-1648

 

 

Kinetics and mechanism of C16TAB catalyzed oxidation of methylene violet by chloramine-T in acidic medium

V W Bhagwat, Mona Pipada, S B Jonnalagadda & Brijesh Pare*

 

Kinetics and mechanism of uncatalyzed and C16TAB catalyzed oxidation of methylene violet (3-amino-7-(diethyamino)-5-phenyl phenazinium chloride) (MV+) by chloramine-T in acidic media has been kinetically studied using spectrophotometry. With excess concentrations of other reactants, the reaction rate follows pseudo-first order kinetics with respect to methylene violet. The uncatalyzed reaction has first order dependence on chloramine-T and zero order dependence on H+ concentrations (in the range 1.010-2 to 6.010-2 M). The reaction is catalyzed by cetyltrimethyl ammonium bromide, a cationic surfactant, even before the cmc. A bathochromic shift is the evidence of dye-surfactant interaction. The pre-micellar kinetics has been rationalized in the light of Piszpiwicz positive co-operativity. Positive cooperatively index (n = 2.7) has been computed. The order in [Cl-] is unity. Variation of ionic strength and the initial addition of p-toluenesulphonamide have no influence on the reaction rate. The rate of depletion of the dye decreases with the increase in pH from 2 to 6. On the basis of product analysis a pertinent mechanism is proposed.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1649-1651

 

 

Kinetics and mechanism of oxidation of hippuric acid
with Bi(V) in phosphoric acid medium

P M Mishra, A K Jha & C S Jha*

 

Kinetics of oxidation of hippuric acid with phosphato-Bi(V) complex have been investigated in phosphoric acid -HClO4 mixture. The reaction is first order in [oxidant] and fractional order—each in [hippuric acid] and [H+]. Ionic strength has inverse effect on the reaction rate. The effect of added [Bi(III)] is found to be negligible. An outer sphere mechanism consistent with the observed kinetics has been proposed and rate law is derived as

1/kobs = 1/K1 K2 k3 [S] [H+] + 1/k3

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1652-1655

 

 

Synthesis of bis(tri-n-butyltin) esters of
dicarboxylic acid and crystal structure of the
three-dimensional framework of organotin polymer,
bis(tri-n-butyltin) ester of succinic acid

Handong Yin*, Chuanhua Wang & Chunlin Ma

 

Ten bis(tri-n-buyltin) esters of dicarboxylic acid have been synthesized by the reaction of disodium dicarboxylates with the tri-n-butyltin chloride in 1:2 molar ratio and characterized by elemental analysis, IR, and 1H NMR. The crystal structures of bis(tri-n-benyltin ) ester of succinic acid (2) have been determined by X-ray single crystal diffraction. The crystal belongs to orthorhombic with space group Pccn, a =20.949(3) Å, b=17.470(3) Å, c=20.345(3) Å, =90°, =90°, =90°, V=7445.5(19) Å3, Z=8, Dc=1.242 mg/cm3, =1.365 mm-1, F(000)=2864, R1=0.0544, wR2=0.1417. The tin atom is five-coordinate in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions. The resulting structure is a three-dimensional framework polymer containing two different tin atom. The framework structure contains large ring directed channels along a, b and c-axis.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1656-1660

 

 

Synthesis and characterization of diorganotin esters
of heteroaromatic carboxylic acid and
crystal structure of nBu2Sn(2-PyCO2)2•H2O

Handong Yin*, Chuanhua Wang, Yong Wang & Chunlin Ma

 

Reactions of nBu2SnO with 2-furanyl, 2-furanvingl, 2-thiophenyl, 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 3-indolyl, 3-indolmethyl and 3-indolpropyl carboxylic acids in 1:2 stoichiometry yield complexes of the type nBu2(O2CR)2. These complexes, on treatment with nBu2SnCl2 afford the chloro complexes, nBu2Cl(O2CR). All the complexes have been characterized by elemental analysis, IR and 1H NMR spectral studies. The crystal structure of nBu2Sn(2-PyCO2)2•H2O has been determined by single crystal X-ray diffraction. The crystal belongs to rhombohedral with space group R-3c, a=15.807(3)Å, b=15.807(3)Å, c=15.807(3) Å, =105.717(2)o,=105.717(2)o, =105.717(2)o, Z=6, V=3397(8)Å3, Dc=1.452g/cm3, =1.158mm1, F(000)=1512, R1=0.0447, wR2=0.1038. In crystal, the tin atoms render seven-coordinate in a distorted pentagonal bipyramidal geometry. The two-dimensional network structure is formed by The H-bonding action between the free carboxyl groups and coordinated water molecule.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1661-1665

 

 

Synthesis and characterization of some new
heterochelates of chromium(III)

Kamalendu Dey*, Bijali Bikash Bhaumik, Susobhan Biswas & Saikat Sarkar

 

Some new chromium(III) heterochelates having different coordination environment, synthesized by the reactions of [CrIII(L1)(Py)Cl]2H2O, [CrIII(L2)(Py)Cl]H2O and [CrIII(L3)2(Py)Cl] (ClO4)2 (where L1 and L2 are dianions of quadridentate schiff bases and L3 is a neutral bidentate schiff base) with acetylacetone (Hacac), glyoxime (Hgly), salicylaldehyde (Hsal), N-Phenylsali cyaldimine (Hsalan), anthranilic acid (Hana), picolinic acid (Hpica), orthoaminophenol (Hoap) and orthoaminothiophenol (Hoatp) by a common general route are reported. The elemental analyses, molar conductances, magnetic susceptibilities, molecular weights and spectroscopic data (IR, UV-vis) characterize the newly synthesized complexes. The stereochemistry of the complexes has also been discussed.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1666-1670

 

 

Molecular complexes of paraquat and chloranil with phenylhydrazones

T Charan Singh, P Venkateshwar Rao, T Veeraiah & G Venkateshwarlu*

 

Molecular complexes of paraquat and chloranil with phenylhydrazones have been studied spectrophotometrically in methanol together with those of paraquat in aqueous SDS micellar media. All the complexes exhibit one charge transfer band each in the region where neither of the components have any absorption. The ionisation potentials of the donors have been determined from the positions of the CT bands. The positions of CT bands and the stabilities of the complexes are affected by the substituents. A drastic enhancement in the stabilities of the complexes of paraquat is observed in SDS micellar media, which is attributed to the increase in local concentrations of the components in SDS media.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1671-1673

 

 

Ligand exchange reactions of sodium nitroprusside in the presence of sulphate ion under photochemical conditions

Mayank R Mehta, Piyush J Vyas, Jitendra Vardia & Suresh C Ameta*

 

Sodium nitroprusside contains cyanide ligands that are not easily replaced chemically. An effort has been made to substitute this ligand by another anionic ligand like sulphate. The rate of this photochemical reaction has been observed spectrophotometrically. The effects of different parameters like pH, light intensity, concentration of sodium nitroprusside and sulphate ligand concentration on the rate of this substitution reaction have been studied. The product is isolated and characterized. A tentative mechanism for this photochemical substitution reaction has been proposed.

 

 

 

Indian Journal of Chemistry

Vol. 42A, July 2003, pp. 1674-1676

 

 

Solvent extraction of zinc(II), cadmium(II), mercury(II) and bismuth(III) using n-octylaniline and their separations

S R Kuchekar, H R Aher & M B Chavan*

 

Solvent extraction behaviour of zinc(II), cadmium(II), mercury(II) and bismuth(III) with n-octylaniline in different organic solvents from various aqueous acid solutions has been investigated. A scheme for the separation of these metals from each other is developed using dependence of distribution ratio on aqueous to organic phase ratio, selective strippants and also on different organic solvents as diluents. The nature of probable extracted species has been established. The method has been applied to separate and determine zinc and mercury from commercial pharmaceutical preparations. The proposed method is simple, rapid and selective.