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Indian Journal of Chemistry

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

 

VOLUME 43A

NUMBER 2

FEBRUARY 2004

 

CONTENT

Papers

 233

Cation dependence of hydride transfer processes: Quantum chemical approach

Parveen, Harjinder Singh*, P Venugopalan & Tej Vir Singh

 

Role of metal counter ion in hydride transfer processes like MPV reduction is investigated by ab initio studies. The transfer of hydride is facilitated as the Lewis acidity of the metal ion decreases. A range of alkoxides with metal ions of varying Lewis acidities (K+, Na+, Li+, Ca2+, Mg2+, Al3+) is considered.

 240

Synthesis and characterization of highly crystalline conjugated polyparaphenylene and polythiophene conductive polymer thin films

 

 

A Mani*, P Kamaraj & K R Ramakrishnan

 

Molecular, crystalline and morphological characteristics of polyparaphenylene and polythiophene conjugated polymers are reported. The study indicates that intrinsically high structural order of Xcr > 90% and high molecular- and crystalline-anisotropy in the form of lamellar structure is achieved by single step controlled electrochemical synthesis in microemulsion containing anionic or neutral surfactants.

 247

Influence of various parameters on synthesis of AlPO4-5 molecular sieve using hexamethyleneimine template

 

 

N Venkatathri*, S G Hegde & S Sivasanker

 

 AlPO4-5 has been synthesized in aqueous and nonaqueous (ethylene glycol) media using hexamethyleneimine (HEM) as template. The most crystalline sample is obtained at 473 K in 4.5 h from a reaction mixture of composition, Al2O3: P2O5: 1.16HEM: 45H2O. Crystallization is faster with HEM as compared to the conventional templates, viz., triethylamine and cyclohexylamine.

 

 254

Ethylation of ethylbenzene over AFI type molecular sieves

 

 

 

K Joseph Antony Raj & V R Vijayaraghavan*

 

Magnesium, manganese and zinc incorporated aluminophosphate molecular sieves, MgMnAPO-5 and MnZnAPO-5, have been prepared by hydrothermal methods. The catalytic performance of these materials has been examined for ethylation of ethylbenzene with ethanol in the vapour phase. Maximum conversion (20.1%) has been noted at 350oC over MnZnAPO-5.

 258

 Effect of organized assemblies. Part I — Effect of variation in chain length of carboxy and alkoxy end of esters on the hydrolysis of simple aliphatic esters

  

Ranjib Padhi, Shreelata Mishra, Pramila K Misra* & B K Sinha

 

 265

 Thermodynamics of micellization and interfacial adsorption of polyoxyethylene (10) lauryl ether (C12E10) in water

 

K Shivaji Sharma & A K Rakshit*

 

The interfacial and micellization properties of polyoxyethylene (10) lauryl ether at different pHs and temperatures have been investigated from surface tension measurements. Both micellization and adsorption processes are endothermic at all pHs. An enthalpy-entropy compensation effect has been observed with an isostructural temperature of 300 K for both the processes. The cloud point of C12E10 is not much affected by pH.

270

New binuclear oxygen carriers of the type [M-mac-M¢(L)4]Cl2.(ClO4)2 where M-mac = Co(II) and Ni(II) 1,8-dihydro-1,3,6,8,10,13-hexaazacyclotetradecane, M¢= Mn(II), Ni(II), Cu(II) and L= tetra(3-acetyl pyridine) and their kinetic studies with H2O2

 

Sartaj Tabassum*, Shaiba Parveen & Farukh Arjmand

 

Novel binuclear complexes of the type [M-mac-M¢(L)4]Cl2.(ClO4)2 derived from 14-membered hexaazacyclotetradecane and tetra(3-acetyl pyridine) of MnII, NiII and CuII chloride have been synthesized. These binuclear complexes have square pyramidal geometry and are ionic in nature. The catalytic oxidation and mechanism of binding to the complexes by hydrogen peroxide have been studied kinetically.

Notes

 278

Copolymerisation and thermal behaviour of styrene: n-decyl/dodecyl itaconate copolymer —Part II

 

 

 

 

Gulshan Kumar, Saroj Aggarwal* & Veena Choudhary

 

Synthesis and characterization of n-decyl itaconate and n-dodecyl itaconate monomers and their homo-polymerisation and copolymerisation with styrene in bulk using azobisisobutyronitrile as an initiator have been reported. Intrinsic viscosity (h) of the copolymers decreases with increase in amount of itaconate in the copolymers. Despite very high molecular weight, the homopolymers have a very low value of h (2±0.5 ml/g). Glass transition temperature is dependent on the copolymer composition.

 282

Synthesis of PZT thin films by sol-gel process and its characterization

 

   

Rashmi Singhai*, Vivek Tiwari & K Sreenivas

 

Ferroelectric Pb(Zr,Ti)O3 (PZT) thin films have been fabricated by the alkoxide based sol-gel method by spin coating PZT solution on glass, silicon and metallised silicon substrate. The PZT thin films have been annealed at various temperatures and characterized by X-ray diffraction and scanning electron microscope.

 285

Preparation and characterization of high specific surface area Ce0.5Zr0.5O2 mixed oxide

 

Jiang Xiaoyuan*, Lu Zheng, Zhang Yu, Ding Guanghui, & Zheng Xiaoming

 

A high specific surface area Ce0.5Zr0.5O2 mixed oxide has been prepared by co-precipitation method with Ce(NO3)3 and Zr(NO3)4 as raw materials. At 70% of surfactants, pH 9.5, ageing time 120 h and calcination at 923K for 2 h, a specific surface area of 279.69m2/g is obtained.

 291

Dielectric relaxation studies of ternary liquid mixtures of alcohols with triethylamine in the microwave region

 

T Kalaivani, S Kumar* & S Krishnan

 

 The dielectric behaviour of hexanol, heptanol and octanol and their mixtures with triethylamine have been studied at microwave frequency of 9.36 GHz at 303K.

294

Volumetric and ultrasonic study of binary liquid mixtures of m-xylene with 1-alkanols at 303.15 K

 

C L Prabhavathi*, K Sivakumar, P Venkateswarlu & G K Raman

 

Excess molar volumes for binary mixtures of m-xylene with 1-propanol, 1-butanol and 1-pentanol have been measured at 303.15 K. Isentropic compressibilities have also been computed for the same The experimental results are discussed in terms of intermolecular interactions between unlike molecules.

299

Thermogravimetric and differential thermal analysis of bipyridyl, ortho-phenylenediamine and 1,10 phenanthroline complexes of some Cu(II) salts

 

L S Prabhumirashi* & J K Khoje

 

Thermal studies of bpy, opd and phen complexes of Cu(II) salts show that the process takes place in the following stages: liquefaction, dehydration, deamination, deanionation and oxidation of Cu.  The steps are composite in nature consisting of simultaneous loss of the component moieties in varying proportions.

 

 303

Kinetics and mechanism of oxidation of
vitamin E by sulphate radical anion in aqueous acetonitrile solution

 

Midudhula Sudha Swaraga & Mundra Adinarayana*

 

 The photooxidation of vitamin E by peroxydisulphate (PDS) in aqueous solution at pH 7.5 has been carried out in a quantum yield reactor using a high pressure mercury vapour lamp. The rate of photooxidation increases with increase in [vitamin E], [PDS] and light intensity. The quantum yield increases with increase in [vitamin E] and is independent of [PDS] and light intensity.

Text Box: 307

Photo-assisted reactions of thiourea with H2O2, Fenton and other related reagents

 

 

S K Sharma, Rekha Vaidya & V K Vaidya*

 

 

Fe2+ + H2O2 + H+                           Fe3+ + OH + H2O

 

TU + 2OH          U + S + H2O

 

 310

Phenol amide chelates of iron(III). Interaction of 1,5- bis - (2-hydroxybenzamido) - 3-aza - pentane with iron(III) in aqueous methanol medium

 

Anadi C Dash* & Rohit K Rath 

 

 Complexation equilibrium of 1,5-bis-(2-hydroxybenz-amido) - 3-azapentane with Fe(OH2)63+ has been investigated at 25.0°C and I = 0.5 mol dm-3 in aqueous methanol. Formation of only the mononuclear complex indicates iron(III) promoted amide deprotonation in mild acidic and mild alkaline medium.

 315

Synthesis, spectroscopic studies, molecular structure optimization and superoxide dismutase activity of copper(II) and zinc(II) bipyridyl assisted supramolecular motifs containing octadentate schiff base

 

Lallan Mishra*, Kumari Bindu & Subrato Bhattacharya 

 

 320

Tetraazamacrocycles of manganese and iron metals: Synthesis, spectroscopic characterization and biological evaluation

 

Ashu Chaudhary, Nidhi Bansal, Nighat Fahmi & R V Singh*

 

 323

Synthesis and characterization of some homo/hetero binuclear hydrido carbonyl ruthenium(II) polypyridyl complexes

 

Manish Chandra, Abhaya Nand Sahay & Daya Shankar Pandey* 

 

The mononuclear hydrido carbonyl complex, [RuH(CO)(PPh3)2(h2-tptz)]BF4, has been used as a building block in the synthesis of homo/hetero binuclear complexes with K2PtCl4, [PdCl2(PhCN)2] and some chloro-bridged dimeric arene ruthenium complexes. [RuH(CO)(PPh3)2(tptz)]BF4 behaves as a potential metallo-ligand.

 329

Synthesis, characterisation and properties of manganese(II) complexes having pseudohalide coordination : X-ray crystal structure of an unusually distorted hexacoordinated [MnL(NCS)](ClO4) species (L = pentadentate Schiff base ligand)

 

Soma Deoghoria, Golam Mostafa, Tian-Huey Lu & Swapan K Chandra*

 

 333

Synthesis, characterization and electrical conductivities of some transition metal complexes of N-benzoyl-N¢-p-hydroxythiobenzhydrazine

 

N K Singh* & S K Kushawaha

 

 

 337

Copper(II) complexes of tetraazamacrocycles derived from b-diketones and diaminoalkanes

 

  

R N Prasad*, Mithlesh Agrawal & Sanjna Sharma

 

 341

Synthesis and structural studies on the metal complexes of a bis-chelating ligand exhibiting mixed denticities

 

  

 

Saritha Reddy, Susheela & Jayatyagaraju* 

 

 

Book Review

 346

Analysis and characterisation of polymers (Editor: Sukumar Maiti)

  

Premamoy Ghosh

 

 

 346

Erratum 

Authors for correspondence are indicated by (*)

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 233-239

 

Cation dependence of hydride transfer processes:
Quantum chemical approach

Parveen, Harjinder Singh*, P Venugopalan & Tej Vir Singh

 

The role of the metal counter ion in hydride transfer processes like MPV reduction is investigated by ab initio theoretical studies. The feasibility of the hydride shift as a function of the nature of the metal counter ion in the alkoxide is studied at HF/6-31G** and MP2/6-31G**//HF/6-31G**. The transfer of hydride is facilitated as the Lewis acidity of the metal ion decreases. A range of alkoxides with metal ions of varying Lewis acidity (K+, Na+, Li+, Ca2+, Mg2+, Al3+) is considered.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 240-246

 

Synthesis and characterization of highly crystalline conjugated polyparaphenylene and
polythiophene conductive polymer thin films

A Mani*, P Kamaraj & K R Ramakrishnan

 

Molecular, crystalline and morphological characteristics of polyparaphenylene (PPP) and polythiophene (PTh) conjugated polymers are reported here. Thin films of PPP and PTh exhibit molecular- and crystalline-anisotropic structures, obtained intrinsically by a single-step approach of electrochemical method. The unique advantage of controlled electrochemical polymerization/crystallization is highlighted by ex-situ high-temperature X-ray diffraction, morphology, luminescence, and ex-situ electrochemical X-ray diffraction data. Structural analysis in terms of degree of crystalline order (Xcr) as the crystalline-gauging parameter and X-ray diffraction profile data as molecular order probe have been reported. The electrochemical thickness effect, high degree of crystalline order (Xcr= 99%), and thin film and molecular anisotropy are highlighted in terms of supramolecular order of the highly conjugated polymer molecules.

 

 

 

Indian Journal of Chemistry 

Vol. 43A, February 2004, pp. 247-253

 

Influence of various parameters on synthesis of AlPO4-5 molecular sieve using hexamethyleneimine template

N Venkatathri*, S G Hegde & S Sivasanker

 

AlPO4-5 has been synthesized in aqueous and nonaqueous (ethylene glycol) media using hexamethyleneimine (HEM) as template. The ideal gel composition for the synthesis of AlPO4-5 is Al2O3 : P2O5 : 1.16HEM : 45H2O. The influence of compositional variations on the product and the effect of pH and temperature on crystallization kinetics have been investigated. Varying the composition of the gel produces other aluminophosphates such as AlPO4-16, AlPO4-22, AlPO4-31 and SAPO-35. Crystallization is faster when HEM is used as the template than when triethylamine or cyclohexylamine is used. The crystallinity (X-ray) of the AlPO4-5 samples synthesized from the nonaqueous medium are higher than those obtained from aqueous media.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 254-257

 

Ethylation of ethylbenzene over AFI type molecular sieves

K Joseph Antony Raj & V R Vijayaraghavan*

 

Magnesium, manganese and zinc incorporated aluminophosphate molecular sieves, MgMnAPO-5 and MnZnAPO-5, have been prepared by hydrothermal methods. The samples have been characterised by the techniques of XRD, FT-IR, 31P and 27Al MAS-NMR spectroscopy, BET-surface area, n-butylamine-TPD and ICP-MS. The catalytic performance of these materials has been examined for ethylation of ethylbenzene with ethanol in the vapour phase. MnZnAPO-5 has been found to be more active than MgMnAPO-5. The products are PDEB (1,4-diethylbenzene), MDEB (1,3-diethylbenzene), ODEB (1,2-diethylbenzene), PAB [(1,2,4 and 1,3,5-triethylbenzene) and (1,2,4,5-tetraethylbenzene)]. Maximum conversion (20.1%) has been noted at 350oC over MnZnAPO-5.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 258-264

Effect of organized assemblies. Part I—Effect of variation in chain length of carboxy and alkoxy end of esters on the hydrolysis of simple aliphatic esters

 Ranjib Padhi, Shreelata Mishra, Pramila K Misra* & B K Sinha

 

The hydrolysis of some simple aliphatic esters having variation in number of carbon atoms in their alkoxy and carboxy part has been carried out in presence of ionic and non-ionic micelles to investigate the effect of the subsequent change in chain length on the mechanism of hydrolysis of esters. The effect of variation of temperature, concentration of salt, substrate, surfactant, and acid has also been examined. The results have been ascribed to the role of the charge of surfactants and partitioning of the substrate into the surfactant aggregates.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 265-269

 

Thermodynamics of micellization and interfacial adsorption of polyoxyethylene (10) lauryl ether (C12E10) in water

K Shivaji Sharma & A K Rakshit*

 

The interfacial and micellization properties of nonionic surfactant, polyoxyethylene (10) lauryl ether [C12E10; CH3 (CH2)11(OCH2CH2)10OH] at different pHs and temperatures have been investigated from surface tension measurements. The surface excess (G) and the corresponding interfacial quantities have been evaluated. The Gibbs free energy, enthalpy and entropy of micellization (DGom, DHom, DSom), and of adsorption at the air/water interface (DGoad, DHoad, DSoad) have also been computed. Both micellization and adsorption processes have been found to be endothermic at all pH. An enthalpy-entropy compensation effect has been observed with an isostructural temperature of 300 K for both the micellization and interfacial adsorption processes. The cloud point of C12E10 is not much affected by pH.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 270-277

 

New binuclear oxygen carriers of the type
[M-mac-M¢(L)4]Cl2.(ClO4)where M-mac = Co(II) and
Ni(II) 1,8-dihydro-1,3,6,8,10,13-hexaazacyclotetradecane, M¢= Mn(II), Ni(II), Cu(II) and L= tetra(3-acetyl pyridine) and their kinetic studies with H2O2

Sartaj Tabassum*, Shaiba Parveen & Farukh Arjmand

 

Novel binuclear complexes of the type [M-mac-M¢(L)4]Cl2.(ClO4)2 derived from 14-membered hexaazacyclotetradecane and second generation tetra-pyridyl complexes¾tetra(3-acetyl pyridine) of MnII, NiII and CuII chloride have been synthesized. On the basis of spectral data, it is inferred that all the binuclear complexes are consistent with square pyramidal geometry and are ionic in nature. The catalytic oxidation and mechanism of binding to the complexes by hydrogen peroxide have been studied kinetically. The progress of the reaction of the representative complex, [C36H50N10O4CuCo]Cl2.(ClO4)2, with H2O2 in aqueous DMSO (95:5) at room temperature has been monitored by measuring absorbance changes at 344 nm (lmax of binuclear CuII-CoII complex with H2O2) under varying concentrations of H2O2 (0.10- 0.16 mol dm3). Pseudo-first order rate constants, kobs have been calculated using linear least squares regression method. The redox behavior of the binuclear complex [C36H50N10O4CuCo]Cl2.(ClO4)2 has been studied in presence and in absence of H2O2 at a scan rate of 0.1 Vs-1 by cyclic voltammetry. The cyclic voltammogram of the CuII-CoII complex reveals quasi-reversible redox waves for one electron transfer attributed to CuII/CuI and CoII/CoI redox couples. On interaction with H2O2, E0 values shift considerably as the coordination environment changes from five-coordinate to six-coordinate geometry due to catalytic oxidation of the complex by H2O2.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 278-281

 

Copolymerisation and thermal behaviour of styrene:
n-decyl/dodecyl itaconate copolymer¾Part II

Gulshan Kumar, Saroj Aggarwal* & Veena Choudhary

 

The synthesis and characterization of n-decyl itaconate (DI) and n-dodecyl itaconate (DDI) monomers and their homopolymerisation and copolymerisation with styrene in bulk using azobisisobutyronitrile (AIBN) as an initiator have been reported. The copolymer compositions have been determined from 1H-NMR. The reactivity ratios determined using Fineman-Ross and Kelen-Tudos method have been found to be r1 = 1.2 (styrene), r2 = 0.70 (DI) and r1 = 1.1 (styrene), r2 = 0.9 (DDI). All the samples have high moleculer weight, Mn in the range of 13 ×103 - 43 ×103 and Mw in the range of 25 ×103 - 88×103 with a polydispersity index in the range 1.71-2.15. Intrinsic viscosity (h) of the copolymers decreases with increase in amount of itaconate in the copolymers. Inspite of having very high molecular weight, the homopolymers (PDI, PDDI) have a very low value of h (2±0.5 ml/g). Glass transition temperature as determined by DSC is found to be dependent on the copolymer composition. Thermal stability of the copolymers has been determined by recording TG/DTG traces in nitrogen atmosphere.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 282-284

 

Synthesis of PZT thin films by sol-gel process and
its characterization

Rashmi Singhai*, Vivek Tiwari & K Sreenivas

 

Ferroelectric Pb(Zr,Ti)O3 (PZT) thin films have been fabricated by the alkoxide based sol-gel method. PZT stock solutions have been spin coated on glass, silicon and metallised silicon substrate. The coating is repeated until 0.6 mm thickness of film has been deposited on various substrates. PZT thin films have been annealed at various temperatures and characterized by X-ray diffraction and scanning electron microscope. Dielectric constant and dielectric loss of PZT thin films has also been measured at different frequencies.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 285-290

 

Preparation and characterization of high specific surface area Ce0.5Zr0.5O2 mixed oxide

Jiang Xiaoyuan*, Lu Zheng, Zhang Yu, Ding Guanghui & Zheng Xiaoming

 

A high specific surface area Ce0.5Zr0.5O2 mixed oxide has been prepared by means of a co-precipitation method with Ce(NO3)3 and Zr(NO3)4 as raw materials. Experimental results show that specific surface area of the Ce0.5Zr0.5O2 mixed oxide is largely affected by the amount of surfactants added, pH and ageing time. Specific surface area was up to 279.69m2/g at 70% of surfactants, pH 9.5, ageing time 120 h and calcination at 923K for 2 h. Analysis by FT-IR indicates that the remaining surfactants are removed after calcination at 923K for 2 h. There are two weightless phenomena in the TG curve and two heat-absorptive peaks in the DTA curve. The first heat-absorptive peak is the desorption process of adsorbed water and acetone at 373K and weightless ratio of 7.43%, and the second peak is the decomposition of the surfactants at 773K. The N2 adsorption-desorption experiment indicates that all the materials are porous and the N2 isotherms of all powders are of type IV, typical of a mesoporous sample. The XRD analysis shows the diffraction peak of Ce0.5Zr0.5O2 mixed oxide between 2q 29.1º, 34º and 48.5º. The Ce0.5Zr0.5O2 mixed oxide possesses even grain size and stable crystalline structure, and its specific surface areas are 230.69, 120.55 and 53.53 m2/g after calcination at 973, 1073 and 1173 K for 2 h, respectively.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 291-293

 

Dielectric relaxation studies of ternary liquid mixtures of alcohols with triethylamine in the microwave region

T Kalaivani, S Kumar* & S Krishnan

 

The dielectric behaviour of three alcohols and their mixtures (i) hexanol + triethylamine (ii) heptanol + triethylamine (iii) octanol + triethylamine have been studied at microwave frequency 9.36 GHz at 303K. Different dielectric quantities like dielectric constant () dielectric loss (e¢¢), static dielectric constant (eo) and dielectric constant at optical frequency (e¥) have been determined. The relaxation time (t) has been calculated by both Higasi’s method and Cole-Cole method. The molar free energy of activation (DFt) and (DFh) have also been reported.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 294-298

 

Volumetric and ultrasonic study of binary liquid mixtures
of m-xylene with 1-alkanols at 303.15 K

C L Prabhavathi*, K Sivakumara, P Venkateswarlub & G K Ramanb

 

New experimental data for excess molar volumes (VE) for binary mixtures of m-xylene with 1-propanol, 1-butanol and 1-pentanol have been measured at 303.15 K. Excess volume exhibits an inversion in sign in all the three binary mixtures. Isentropic compressibilities (Ks) have been computed for the same 1-alkanols from precise sound velocity and density data. The deviation in isentropic compressibility (DKs) from ideality is also computed. DKs values exhibit an inversion in sign in all the binary mixtures of m-xylene with 1-alkanols. The experimental sound velocity data have been analysed in terms of Free length theory (FLT) and Collision factor theory (CFT). The experimental results are discussed in terms of intermolecular interactions between unlike molecules.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 299-302

 

Thermogravimetric and differential thermal analysis of bipyridyl, ortho-phenylenediamine and 1,10 phenanthroline complexes of some Cu(II) salts

L S Prabhumirashi* & J K Khoje

 

Dynamic TGA and DTA studies on thermal decomposition of coordination complexes of bipyridyl, ortho-phenylenediamine and 1,10 phenanthroline with Cu(II) chloride, nitrate, sulphate, acetate and oxalate reveal that the process occurs through the stages: liquefaction, dehydration, deamination, deanionation and oxidation of Cu. All the steps are composite in nature consisting of simultaneous loss of the component moieties in varying proportions and the related DHs and Eas are significantly dependent on the nature of the co-anions and ligands.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 303-306

 

Kinetics and mechanism of oxidation of vitamin E by sulphate radical anion in aqueous acetonitrile solution

Midudhula Sudha Swaraga & Mundra Adinarayana*

 

The photooxidation of vitamin E (a-tocopherol) in the presence of peroxydisulphate (PDS) in aqueous solution at natural pH (7.5) has been carried out in a quantum yield reactor using a high pressure mercury vapour lamp. The rate of photooxidation increases with increase in [vitamin E], [PDS] and light intensity. The quantum yield increases with increase in [vitamin E] and is independent of [PDS] and light intensity. The plots of log (rate) versus log [PDS] and the log (rate) versus log [vitamin E] are linear with a slope of less than one indicating fractional order dependence of rate on [PDS] as well as on [vitamin E]. On the basis of experimental results and product analysis a probable mechanism is suggested.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 307-309

 

Photo-assisted reactions of thiourea with H2O2, Fenton
and other related reagents

S K Sharma, Rekha Vaidya & V K Vaidya*

 

Photo-assisted reaction of thiourea with H2O2, Fenton reagent (H2O2 + FeSO4) and other related reagents (H2O2+ U(VI)/methylene blue) have been studied. The rate of photo chemical reaction increases with increase in [substrate], [H2O2], [H+] and increases with increase in polarity of solvents. The rate of oxidation of thiourea shows marked increase with other related reagents. Involvement of free radicals have been confirmed. A probable mechanism has been proposed.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 310-314

 

Phenol amide chelates of iron(III). Interaction of
1,5-bis-(2-hydroxybenzamido)-3-aza-pentane with iron(III)
in aqueous methanol medium

Anadi C Dash* & Rohit K Rath

 

The complexation equilibrium of 1,5-bis-(2-hydroxybenza-mido)-3-azapentane with Fe(OH2)63+ has been investigated at 25.0°C and I = 0.5 mol dm-3 in aqueous methanol [2.5% MeOH + H2O (v/v)]. The formation of only the mononuclear complex has been observed which led to the iron(III) promoted amide deprotonation in mild acidic (pK1(CO-NH) = 5.2) and mild alkaline (pK2(CO-NH) = 9.2) medium. The ligand is a very good iron(III) sequestering agent with log Kstab = 23.3 (Fe3+ + L2- = FeL+, Kstab).

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 315-319

 

Synthesis, spectroscopic studies, molecular structure optimization, and superoxide dismutase activity of copper(II) and zinc(II) bipyridyl assisted supramolecular motifs containing octadentate schiff base

 

Lallan Mishra*, Kumari Bindu & Subrato Bhattacharya

 

Schiff base N,N¢,N¢¢,N¢¢¢-tetrasalicylidene-3,3¢-diamino-benzidine (H4tsdb) and its dinuclear [M2(bpy)2.tsdb].2DMSO. 8H2O; bpy=2,2¢-bipyridine; M=Cu(II) 1, M=Zn (II) 2, complexes have been prepared and characterized by their elemental analysis, FAB-mass, IR, NMR (1H,13C and 1H-1H COSY), UV-vis, ESR (Cu(II) only) spectra and magnetic-moment data. Force field calculations reveal highly distorted octahedral environment around both the metal centers. The Cu-Cu and Zn-Zn distances are found to be 12.28 and 12.37Å, respectively. Superoxide dismutase activity of the complexes has also been studied.

 

 

 

Indian Journal of Chemistry

Vol. 43, February 2004, pp. 320-322

 

Tetraazamacrocycles of manganese and
iron metals: Synthesis, spectroscopic characterization
and biological evaluation

Ashu Chaudhary, Nidhi Bansal, Nighat Fahmi & R V Singh*

 

A new series of 14 to 20 membered tetraazamacrocyclic complexes of the type [M(Macn)Cl2], where, M = Fe(II) and Mn(II), have been synthesized by the template condensation of 1,2-phenylenediamine with dicarboxylic acids (malonic, succinic, glutaric and adipic). The compounds have been characterized by elemental analysis, IR, electronic, 57Fe mössbaur, magnetic moment, conductivity, mass and X-ray spectral studies. These studies show that the compounds are monomers having an octahedral geometry. All the complexes have been screened against several fungi and bacteria and the results have been discussed.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 323-328 

 

Synthesis and characterization of some
homo/hetero binuclear hydrido carbonyl ruthenium(II) polypyridyl complexes

Manish Chandra, Abhaya Nand Sahay & Daya Shankar Pandey*

 

Mononuclear hydrido carbonyl complex [RuH(CO)(PPh3)2-(h2-tptz)]BF4 (tptz = 2,4,6-tris-(2¢-pyridyl)-1,3,5-triazine) has been used as a building block in the synthesis of homo/hetero binuclear complexes. The complex [RuH(CO)(PPh3)2(tptz)]BF4 behaves as a potential metallo-ligand. Its reaction with different molecules ranging from K2PtCl4, [PdCl2(PhCN)2], chloro-bridged dimeric arene ruthenium complexes [{Ru(h6-arene)(m-Cl)Cl}2] (arene = p-cymene or benzene), [{Rh(h5-C5Me5)(m-Cl)Cl}2] and [Rh(COD)(m-Cl)]2 (COD = 1,5-cyclooctadiene) leads to the formation of binuclear complexes. The homo and hetero binuclear tptz bridged complexes [RuH(CO)(PPh3)2(m-tptz)PtCl2]BF4, [RuH(CO)(PPh3)2(m-tptz)PdCl2]BF4, [RuH(CO)(PPh3)2(m-tptz)-(h6-C10H14)RuCl](BF4)2, [RuH(CO)(PPh3)2(m-tptz)(h6-C6Me6)-RuCl](BF4)2, [RuH(CO)(PPh3)2(m-tptz)(h2-COD)Rh](BF4)2 and [RuH(CO)(PPh3)2(m-tptz)Rh(h5-C5Me5)Cl](BF4)2 have been synthesized and characterized using IR, NMR, ESMS and FAB mass spectra.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 329-332

 

Synthesis, characterisation and properties of
manganese(II) complexes having pseudohalide coordination: X-ray crystal structure of an unusually distorted hexacoordinated [MnL(NCS)](ClO4) species
(L = pentadentate Schiff base ligand)

Soma Deoghoriaa, Golam Mostafab, Tian-Huey Lub & Swapan K Chandra*a

 

The synthesis, characterisation and properties of manganese(II) complexes from a pentadentate ligand (L) and pseudohalide anions having composition [MnL(X)](ClO4), where X = NCS (1), X = N3 (2) and X = NCO (3), is described. The structure of 1 has been determined by single crystal X-ray diffraction studies. The structure determination reveals that the manganese atom is hexacoordinated with an unusual distortion in the coordination sphere of this type of linear pentadentate ligand and thiocyanato anion acts as a terminal donor.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 333-336

 

Synthesis, characterization and electrical conductivities of some transition metal complexes of
 N-benzoyl-N¢-p-hydroxythiobenzhydrazine

N K Singh* & S K Kushawaha

 

A new potential tetradentate ligand, N-benzoyl-N¢-p-hydroxythiobenzhydrazine (H2Bptbh) has been found to form complexes [VO(Bptbh)], [Fe(HBptbh)2(acac)] and [M(HBptbh)2] (M = CuII, ZnII, CdII) by loss one or two proton(s) from the ligand. The complexes have been characterized by elemental analyses, magnetic susceptibility measurement, UV-vis, IR, ESR, 1H NMR, Mössbauer and FAB mass spectral studies. The room temperature ESR spectra of OVIV, FeIII and CuII complexes yield <g> values characteristic of square pyramidal, octahedral and square planar complexes, respectively. The Mössbauer spectra of [Fe(HBptbh)2(acac)] at room temperature and 78 K suggest the presence of high spin FeIII. The solid state conductivity of [VO(Bptbh)], [Fe(HBptbh)2(acac)] and [Cd(HBptbh)2], increase in temperature range 323-333 K with a band gap of 0.42-0.75 eV, indicating their semiconducting behaviour. Other complexes are insulators.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 337-340

 

Copper(II) complexes of tetraazamacro-cycles derived from
b-diketones and & diaminoalkanes

R N Prasad*, Mithlesh Agrawal & Sanjna Sharma

 

Cu(II) complexes of the type [Cu(L)](NO3)2 (where L = tetraazamacrocycle with 18 to 34-membered ring) have been synthesized by the template condensation of b-diketones such as 2,4-pentanedione, 1-phenyl-1,3-butanedione and 1,3-diphenyl-1,3-propanedione with various diaminoalkanes. These complexes have been characterized by elemental analyses, molar conductances, magnetic moments and IR and electronic spectra.

 

 

 

Indian Journal of Chemistry

Vol. 43A, February 2004, pp. 341-345

Synthesis and structural studies on the metal complexes of a bis-chelating ligand exhibiting mixed denticities

Saritha Reddy, Susheela & Jayatyagaraju*

 

The complexes of a new bis-chelating ligand derived from 5-acetyl- 2,4-dihydroxyacetophenone and salicyloyl hydrazide (H3- HBADAH) with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) have been synthesized and characterized on the basis of elemental analyses, conductivity, magnetic moments, infrared and electronic spectral data. Metal-to-ligand ratio in all the chelates has been found to be 3:2. The schiff base behaves as a bis-chelating system utilizing a bidentate OO sequence and a tetradentate ONOO sequence. All the complexes have been assigned octahedral stereochemistry. The ligand H3-HBADAH forms polymeric metal complexes with first row transition metal ions.

 

 

 

Indian Journal of Chemistry Vol. 43A, February 2004, pp. 346

 

Book Review

 

Analysis and Characterization of Polymers, Editor: Sukumar Maiti, Anusandhan Prokashan, Midnapore, West Bengal, 2003, pp. 210

 

Reviewed by Prof. Premamoy Ghosh