Indian Journal of Chemistry

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

VOLUME 42A

NUMBER 5

MAY 2003

 

CONTENTS

Papers

 

Two-dimensional phase transitions of water dipoles at mercury/aqueous solution interfaces

S Harinipriya & M V Sangaranarayanan*

965

Decomposition of H2O2 over Cu-Ce-O and Fe-Ce-O composite catalysts prepared by fast combustion method

G Ranga Rao*, H R Sahu & Braja Gopal Mishra

968

Studies on vanadium incorporation in AFI type molecular    sieves

N  Venkatathri*, S G  Hegde & S  Sivasanker

974

Trigonal pyramidal CuIN4 cores assembled by a family of tetradentate N-donor Schiff bases.      Substituent effects on the Cu(II/I) potential

Derek A Tocher, Michael G B  Drew, Shubhamoy Chowdhury & Dipankar Datta

983

Electrooxidation of   5,6-dihydroxytryptamine in aqueous and micellar media

Rajendra N Goyal* & Bhanu P Srivastava

990

Interaction between DL-alanine and ninhydrin in aqueous and aqueous-organic solvents and the effect of surfactant micelles thereon

 Kabir-ud- Din*, Manzoora Bano & Iqrar Ahmad Khan

998

Synthesis, X-ray crystal structure and magnetic properties of a new binuclear complex derived from a pentadentate Schiff base ligand

Soma Deoghoria, W T Wong & Swapan K Chandra*

1004

Liquid-liquid extraction, separation and preconcentration, membrane transportation and ICP-AES determination of vanadium with dibenzo-18-crown-6

Y K Agrawal*, S K Menon & V K Jain

1008

Notes

 

An analysis of the conformation and electronic structure of newly    synthesized cryptand                                   

Rıza Abbasoğlu & Yaşar Gök*

1013

Mathematical simulation of gas phase reactions ¾Combustion of carbon disulphide

Subrato Bhattacharya

1016

A study of the interaction of water vapour on clean and oxidized lead surfaces using photoelectron spectroscopy

Mohammed Hashim Matloob

1021

Non-linear kinetics and mechanism of fructose and bromate reaction in acidic medium

R P Rastogi & Prem Chand

1027

Phase diagram of rubidium carbonate + ethanol + water  ternary system

Yue Tao*,   Gao Shiyang  & Xia Shuping

1031

Electrochemical behavior of Al3Fe in alkaline media

Kaan Cebesoy Emregül

1035

Dominant role of solvent polarity in the reduction kinetics of cobalt(III)-ammine complex in mixed solvents

K  Anbalagan*,  K  A  Danishad & S  P  R  Poonkodi

1040

Acidity function of calcium nitrate tetrahydrate melt

S Dev,  B Sunar, S S Islam &  K Ismail*

1044

Ultrasonic and viscometric studies  of substituted flavone, isoxazole and pyrazole in 70 % acetone water mixture

Pratibha B Agrawal* & M L Narwade

1047

Acoustic properties of substituted thiadiazoles and methyl-5-carboxylates in dioxan -water, ethanol-water and acetone-water mixtures at 298.5+0.1 K

Pratibha B Agrawal*, Mohd Idrees Mohd Siddique & M L Narwade

1050

Oxidation of Co(II) EDTA complex by V(V) under the conditions where VO2+ and decavanadates coexist

G Rama Babu, K Ramakrishna, G Venkateswarlu & P V Subba Rao*

1053

Synthesis  and  characterisation  of  some heterobimetallic  triethanolaminate  derivatives  of alkaline  earth  metals  with  niobium  and  tantalum

Maneesh K Sharma, Malti Sharma, Anirudh  Singh* & Ram C Mehrotra*

1057

Differing modes of crown binding to potassium: K, 18-crown-6 salt of the cyclic phosphate (OCH2CMe2CH2O)P(O)(OH) as a hydrate

Praveen Kommana & K C Kumara Swamy*

1061

Synthesis, structural, thermal and biological  studies of Cr(III), Mn(III), Fe(III), VO(IV), Zr(IV) and UO2 (VI) Schiff base complexes

P R Mandlik, M B More & A S Aswar*

1064

Heterocarboxylates of unsymmetrical tin (IV) aluminium (III) -m- oxoisopropoxyacetate and unsymmetrical tin (IV) aluminium (III) - m - oxoisopropoxide.

Deepali, S Aggrawal & A K Narula*

1068

 

Synthesis and crystal structures of  N-(2,3,4,6-Tetra-O-acetyl-β-D-glycosyl)-thiocarbamoyl methylene diamine

Fangfang Jian*, Huanxiang Wang, Yan Li & Shusheng Zhang

1072

 

La(III) complex of phenanthroline bridging polyamine as efficient catalyst for the hydrolysis of ATP

Yanhe Guo, Qingchun Ge, Hai Lin, Huakuan Lin*, & Shourong Zhu

1076

Spectrophotometric determination of protonation constant of    N–phenylbenzo -hydroxamic acid in mineral acids

Kallol K Ghosh* & Pankaj Tamrakar

1081

Determination of Ni(II) and Co(II) by FAAS after     preconcentration on modified alumina column

Farzaneh Shemirani*, Reyhaneh Rahnama Kozani, Masood Salavati Niasari, Shiva Dehghan Abkenar, Mohammad Reza Jamali & Aazam Alsadat Mirroshandel

1086

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 965-967

 

 

Two-dimensional phase transitions of water dipoles at mercury/aqueous solution interfaces

S. Harinipriya & M V Sangaranarayanan*

 

The critical temperatures pertaining to order-disorder transitions of water dipoles at mercury/aqueous solution interfaces are estimated taking into account the hydrogen bonding considerations and surface coordination effects via Gibbs free energies. The computed values are in agreement with the experimental data deduced using Laser-induced temperature jump methods as well as empirical correlations.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 968-973

 

 

Decomposition of H2O2 over Cu-Ce-O and Fe-Ce-O composite catalysts prepared by fast combustion method

G Ranga Rao, H R Sahu & Braja Gopal Mishra

 

Cu-Ce-O and Fe-Ce-O composite catalysts have been synthesized by solution combustion route. It is found that the copper oxide and iron oxide phases are well dispersed on CeO2 support by this method. All the composite catalysts have been tested for heterogeneous decomposition of H2O2 in neutral solution. The compensation effects have been observed on the composite catalysts. They are correlated to different surface active sites available on dispersed copper oxide and iron oxide phases in the respective composites. The kinetic data clearly show that there is a transformation from dispersed CuO to crystalline CuO with increased copper loading in Cu-Ce-O composite while iron oxide has always been present in highly dispersed state in Fe-Ce-O composite. The XRD and EPR data pertaining to CuO (20 mol%)-CeO2 and Fe2O3 (20 mol%)-CeO2 composite samples are presented.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 974-982

 

 

Studies on vanadium incorporation in AFI type molecular sieves

N Venkatathri*, S G Hegde & S Sivasanker

 

Vanadium aluminophosphates (VAPO-5) and vanadium silicoaluminophosphates (VAPSO-5) have been synthesized with different vanadium and silicon contents using tripropylamine (TPA) and hexamethyleneimine (HEM) as templates. A larger incorporation of V takes place when HEM is used. The studies reveal that vanadium replaces both phosphorous and silicon. The VAPO-5 and VAPSO-5 samples synthesized using hexamethyleneimine have been characterized by XRD, SEM, TG/DTA, FT-IR, UV-vis., ESR, and cyclic voltammetry. About three fourth of the vanadium in the samples are found to be present in a tetrahedral co-ordination and the rest in square pyramidal or distorted octahedral co-ordination. The catalytic activities of the samples in the oxidation of toluene with tertiary butyl hydro peroxide and acetalization of benzaldehyde are presented.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 983-989

 

 

Trigonal pyramidal CuIN4 cores assembled by a family of tetradentate N-donor Schiff bases. Substituent effects on the Cu(II/I) potential

Derek A. Tocher, Michael G. B. Drew, Shubhamoy Chowdhury & Dipankar Datta

 

Copper(I) complexes of 1:3 condensates of tris(2-aminoethyl)amine and p-X-benzaldehydes (X = H, Cl, NMe2 and NO2) of the type [Cu(ligand)]ClO4 are synthesised. The X-ray crystal structures of the copper(I) complexes with X = H, Cl and NMe2 are determined. In these complexes copper(I) is found to have trigonal pyramidal N4 coordination sphere with the apical N forming a longer bond (2.191-2.202 Å) than the trigonal ones (2.003-2.026 Å). The Cu(II/I) potentials in these complexes span a range of 0.71-0.90 V vs SCE increasing linearly with the resonance component of the Hammett  for the para substituent X. It is concluded that trigonal pyramidal geometry is destabilising for copper(II).

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 990-997

 

 

Electrooxidation of 5,6-dihydroxytryptamine in aqueous and micellar media

Rajendra N Goyal* & Bhanu P Srivastava

 

Electrochemical oxidation of neurotoxin 5,6-dihydroxytryptamine has been studied in aqueous and micellar media. In both the media oxidation occurs in two well-defined ,pH dependent peaks involving 4e,4H+ in peak Ia and 2e,2H+ in peak IIa respectively. The spectral studies and products identification corresponding to peak IIa have been carried out in aqueous and micellar media at pH 2.8.The Ep and ip of the oxidation peaks have been found to be dependent on the nature and concentration of surfactants and the observed changes have been explained.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 998-1003

 

 

Interaction between DL-alanine and ninhydrin in
aqueous and aqueous-organic solvents and the
effect of surfactant micelles thereon

Kabir-ud- Din*, Manzoora Bano & Iqrar Ahmad Khan

 

The rates of reaction between ninhydrin and DL- alanine have been determined in water as well as in cationic micelles of CTAB at 80 °C and at pH 5.0. The same products are formed in both the media. It has also been observed that micelles catalyse the reaction which is explained on the basis of pseudo-phase model. The kinetic data have been used to calculate micellar binding constants KS and KN.The effect of different organic solvents on the reaction rate has also been explored.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1004-1007

 

 

Synthesis, X-ray crystal structure and magnetic properties of a new binuclear complex derived from a pentadentate Schiff base ligand

Soma Deoghoria, W T Wong & Swapan K Chandra*

 

A new binuclear nickel(II) complex [Ni2L2(N3)2](ClO4)2 1 has been synthesized and characterized. The structure of 1 has been determined by single crystal X-ray diffraction studies. The structure analysis indicates that each nickel(II) centre is in a distorted octahedral (NiN6) coordination environment with three nitrogen atoms from one and two nitrogen atoms from other pentadentate ligand and the last one from terminal azido ion. Variable-temperature magnetic susceptibility measurements of the compound 1 showed no evidence of magnetic exchange between two nickel(II) centres. This is consistent with the structure with large Ni…Ni distance (5.865(1) Å) and absence of any suitable bridging ligand capable of transmitting this type of interactions.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1008-1012

 

 

Liquid-liquid extraction, separation and preconcentration, membrane transportation and ICP-AES determination of vanadium with dibenzo-18-crown-6

Y K Agrawal*, S K Menon & V K Jain

 

Dibenzo-18-crown-6(DB18C6) is used for the liquid-liquid extraction and membrane transporation of vanadium(V). Vanadium is extracted with DB18C6 in 3.0 M HCl medium using dichloromethane as solvent which forms a colourless complex ( max 285 nm). The complex obeys Beer’s law in the range of 4.25 – 93.5 ng mL-1. The dichloromethane extract is directly inserted into plasma for inductively coupled plasma atomic emission spectrophotometric (ICP-AES) estimation of vanadium, which enhances the sensitivity several folds and the limits for estimation is 0.2 – 5.0 ng mL-1 with detection limit 0.05 ng mL-1. The overall formation constant (log 2K’e) and extraction constant (Ke) calculated are 22.20 and 1.8 x 10-14 at 250 C, respectively. Vanadium is preconcentrated and determined in sea water, standard samples and environmental samples.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1013-1015

 

 

An analysis of the conformation and electronic structure of
newly synthesized cryptand

Rıza Abbasoğlu & Yaşar Gök*

 

Using molecular mechanical methods (MM2, AMBER, OPLS), a confor-mational analysis of a newly synthesized cryptand was made and its stable confor-mations were determined. The electronic structures of the stable conformations were analysed by the AM1 method, and its donor-acceptor characteristics were investigated.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1016-1020

 

 

Mathematical simulation of gas phase reactions - combustion of carbon disulphide

Subrato Bhattacharya

 

Combustion of fossil fuels generate large amounts of toxic gases such as CO, SO2 and SO3. A study of combustion of carbon disulphide may be useful in understanding the nature of products formed and their residence time under defined conditions. The present investigation shows the formation of different transient species and their fate as a function of oxygen concentration. The results show that one of the toxic products, CO, is rapidly oxidised to CO2 and there exists an equilibrium between SO2 and SO3, the ratio of the two oxides being 1:1.107 at equilibrium.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1021-1026

 

 

A study of the interaction of water vapour on clean and oxidized lead surfaces using photoelectron spectroscopy

Mohammed Hashim Matloob

 

The interaction of H2O vapour with clean and oxidized Pb(100) single crystal surfaces has been studied using photoelectron spectroscopy. The clean Pb(100) surface, does not react with H2O vapour at 298 K but physisorbs H2O at a very high sticking probability (~ unity) at 80 K. The adlayer is completely desorbed at 150 K, leaving an atomically clean surface. At 80 K, H2O is molecularly adsorbed on oxidized lead surface without decomposition, but on warming to 298 K there is a strong evidence for a significant decomposition. Exposure of the Pb(100)–O surface to water vapour at 298 K leads to stoichiometric transfer in intensity from the oxide region to the hydroxyl region indicating the formation of PbO(OH)2(s). Oxidized Pb(100) single crystal shows no catalytic tendency to decompose ethylene, propylene and acrolein in the temperature range (298-450 K).

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1027-1030

 

 

Non-linear kinetics and mechanism of fructose
and bromate reaction in acidic medium

R P Rastogi* & Prem Chand

 

Reaction between fructose [F] and bromate (BrO3) is an important component of the F + Ce4+ + BrO3 + H2SO4 oscillatory reaction. Kinetics of this reaction has been experimentally investigated. A reaction mechanism has been proposed which is supported by computer simulation.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1031-1034

 

 

Phase diagram of rubidium carbonate + ethanol +water
ternary system

Yue Tao* , Gao Shiyang & Xia Shuping

 

Isothermal solubilities of rubidium carbonate +ethanol + water ternary system at 0, 20, 30,40 and 60 ºC have been determined and the phase diagrams have also been constructed. The phase diagrams at different temperatures are very similar. Rubidium carbonate could be used to prepare the alcohol with higher purity from alcohol-water solution with different composition easily without distillation and it is much efficient.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1035-1039

 

 

Electrochemical behavior of Al3Fe in alkaline media

Kaan Cebesoy Emregül

 

The behavior of the Al3Fe matrix has been studied in alkaline media in order to simulate the local catholyte chemistry existing on the small cathodic particles on a corroding commercial alloy. The behavior of both pure iron and pure aluminum has also been investigated and the results compared. It has been suggested that the intermetallic phase behaves like an iron electrode overall.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1040-1043

 

 

Dominant role of solvent polarity in the reduction kinetics of
cobalt(III)-ammine complex in mixed solvents

K Anbalagan*, K A Danishad & S P R Poonkodi

 

Outer-sphere electron transfer reaction between Co(NH3)63+ and Fe(CN)64- has been studied as a function of relative permittivity of binary solvent mixtures of water-1,4-dioxane (5-30% (v/v) organic cosolvent). The electron transfer rate constants (ket) increase with increase in mole fraction (x2) of 1,4-dioxane in the mixture. The estimated rate constants have been linearly related to the reciprocal of relative permittivity of the medium (log ket versus 1/r). They have also been correlated with the Grunwald-Wistein empirical parameter, YGW, and Swain’s polarity term (A+B). The results indicate the solvent participation in the formation and stability of ion-pair from Co(NH3)63+ and Fe(CN)64- leading to electron transfer. The rate constants have also been subjected to bi- and tri-parametric analyses to understand the specific and non-specific influence of binary solvent mixtures on reaction rates.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1044-1046

 

 

Acidity function of calcium nitrate tetrahydrate melt

S Dev, B Sunar, S S Islam & K Ismail*

 

Visible spectra of methyl red (MR), methyl orange (MO), p-nitrophenol (PNP), p-nitroaniline (PNA), and bromophenol blue (BPB) in calcium nitrate tetrahydrate (CNTH) melt have been recorded at 25C. All the indicators react with the acidic calcium nitrate tetrahydrate melt. It is found that indicators having high pKa value in the range  4 can be used as probes if the spectra of acidic and basic forms of such indicators in the hydrate melt are well separated. Acidity function of calcium nitrate tetrahydrate melt has been determined from the spectral data of PNA and BPB only and its values, 1.8 and 2.6 respectively are estimated from their respective spectra.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1047-1049

 

 

Ultrasonic and viscometric studies of substituted flavone, isoxazole and pyrazole in 70 % acetone water mixture

Pratibha B Agrawal* & M L Narwade

 

Ultrasonic velocity and viscosity-density of 4'-methoxy-3-(p-methoxycinnamoyl) flavone (L1), 3-(2-hydroxy-5-methylphenyl)-4-benzoyl-5-(p-methoxyphynyl)isoxazole(L2) and 3-(2-hydroxy-5-methylphenyl) -5-methylpyrazole (L3) at different molalities in 70 % (v/v) acetone- water mixture have been measured at 298.5 +0.1K. The values of relative viscosity (rel), apparent molal volume (v) and adiabatic compressibility [k (s)] have been deduced from these data. The structure making and breaking properties of the liquid have been considered as measure of solute-solvent and solute-solute interactions. The results of the present study suggest the presence of short range and weak interactions.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1050-1052

 

 

Acoustic properties of substituted thiadiazoles and
methyl-5-carboxylates in dioxan -water, ethanol-water and
acetone-water mixtures at 298.5+0.1 K.

Pratibha B Agrawal*, Mohd Idrees Mohd Siddique & M L Narwade

 

 

Different acoustic properties like apparent molal volume, apparent molal compressibility, specific acoustic impendance and relative association have been determined in 2-[3′-(2′′-hydroxy-5′′-methylaryl) pyrazol-5′-yl] – 5 – mercapto – 1,3,4-thiadiazole[HMAPMT] and methyl-1-carboxamido-3-(2′-hydroxy-5′-methylphenyl) pyrazole-5-carboxylate [MCHMPPC] in different percentages of dioxan -water, ethanol-water and acetone-water mixtures at 298.5+0.1K. Solute-solvent and solute-solute interactions have been inferred from these measurements.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1053-1056

 

 

Oxidation of Co(II) EDTA complex by V(V) under the conditions
where VO2+ and decavanadates coexist

G Rama Babu, K Ramakrishna, G Venkateswarlu & PV Subba Rao*

 

The oxidation of Co(II) EDTA complex by V(V) in the pH range 3.05 – 4.27 obeys first order kinetics each with respect to vanadium (V) and the complex. The dependence of rate on [H+] is complex. In this pH range V(V) is present in the form of VO2+ and decavanadates, HV10O285- and H2V10O284-,the latter being predominant. The kinetic results show that the rate is almost exclusively determined by paths involving HV10O285- and H2V10O284- the latter being about 9 times more reactive than the former.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1057-1060

 

 

Synthesis and characterisation of some
heterobimetallic triethanolaminate derivatives of
alkaline earth metals with niobium and tantalum

Maneesh K Sharma, Malti Sharma, Anirudh Singh* & Ram C Mehrotra*

 

Hydrocarbon-soluble heterobimetallic triethanolaminate derivatives of the type [{M'(OPri)4}4M{(OCH2CH2)3N}2] (M = Mg, Ca, Sr, Ba; M' = Nb, Ta;) have been prepared by the reactions of hydrocarbon-insoluble homometallic triethanolaminate derivatives M{(OCH2CH2)N(CH2CH2OH) 2}2 with M'(OPri) 5 in 1:4 molar ratio in benzene. All of these derivatives have been characterised by elemental analyses, spectroscopic [IR, NMR (1H and 13C)] studies as well as molecular weight determinations.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1061-1063

 

 

Differing modes of crown binding to potassium: K, 18-crown-6 salt of the cyclic phosphate (OCH2CMe2CH2O)P(O)(OH) as a hydrate

Praveen Kommana and K C Kumara Swamy*

 

The molecular structure of [K, 18-crown-6]+[(OCH2CMe2CH2O)P(O2)]-.H2O (3) has been determined. Potassium is eight-coordinate and is connected to an oxygen of the phosphate (that is not part of the six-membered ring), the water oxygen and six oxygen atoms of the crown. The two non-crown oxygens coordinated to potassium are on the same side with respect to the mean plane of the crown oxygen atoms; this mode of coordination is different from that observed in [K, 18-crown-6]+[myo-C6H6-2-{OC(O)Ph}-1,3,5-(O3CH)-{4,6-O2P(O)O}]-.3H2O (2) in which the coordination of the non-crown oxygens (an oxygen from the inositol residue and an oxygen from the phosphate) occurs from the opposite sides of the mean plane of the crown oxygen atoms. The water oxygen is hydrogen bonded to two oxygen atoms (that are not part of the six-membered ring) of the phosphate leading to a chain. The six-membered phosphorinane ring has a chair conformation.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1064-1067

 

 

Synthesis, structural, thermal and biological studies of Cr(III), Mn(III), Fe(III), VO(IV), Zr(IV) and UO2 (VI) Schiff base complexes

P R Mandlik , M B More & A S Aswar*

 

Complexes of Cr(III), Mn(III), Fe(III), VO(IV), Zr(IV) and UO2 (VI) with Schiff base derived from 2-hydroxy-5-chloroacetophenone and isonicotinoyl hydrazide (HCAIH) have been prepared and characterized by elemental analysis, IR, molar conductance, electronic spectra, magnetic susceptibility measurements and thermogravimetric (TG) analysis. The HCAIH acts as monobasic bidentate ON donor towards Cr(III), Fe(III), and Zr(IV) monobasic tridentate ONO donor towards UO2 (VI) and dibasic tridentate ONO donor towards Mn(III) and VO(IV). The Mn(III) complex has been assigned square pyramidal and the VO(IV) complex has been assigned dimeric square pyramidal structure while all other complexes are octahedral. TG data shows that first order kinetics in all complexes and thermal activation energies have also been calculated by using Broido method. The antimicrobial activities of the ligand and its metal complexes have been studied by screening the compounds against various micro-organisms and the results have been compared.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1068-1071

 

 

Heterocarboxylates of unsymmetrical tin (IV) aluminium (III) -- oxoisopropoxyacetate and unsymmetrical tin (IV) aluminium (III) -  - oxoisopropoxide.

Deepali, S Aggrawal & A K Narula*

 

Unsymmetrical heterocarboxylates complexes of the type, BuMeSn(OAc)OAl (OPri)2-nLn and BuMeSnO2Al2(OPri)4-nLn (where n=1 or 2), derived from heterocarboxylic acids viz, indole-3-carboxylic acid, indole-3- propionic acid and indole-3-butyric acids have been synthesized by the reaction of unsymmetrical tin (IV) aluminium (III) - μ - oxoisopropoxyacetate and unsymmetrical tin (IV) aluminium (III) - μ - oxoisopropoxide respectively. The complexes have been characterized by elemental analyses and IR and NMR (1H, 13C, 27Al, 119Sn) spectra.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1072-1075

 

 

Synthesis and crystal structures of
N-(2,3,4,6-Tetra-O-acetyl-β-D-glycosyl)-thiocarbamoyl
methylene diamine

Fangfang Jian*, Huanxiang Wang, Yan Li & Shusheng Zhang

 

The structure of N-(2,3,4,6-tetra-O-acetyl-β-D-glycosyl)-thiocarbamoyl methylene diamine, C16H25N3O9S has been determined by X-ray diffraction method. It crystallizes in the monoclinic system, space group P21, with lattice parameters a = 7.6560(2), b = 10.3113(3), c =14.1813(1)Å,  = 100.879 (2), and Z = 2. The hexapyranosyl ring adopts a chair conformation. All the ring substituents are in the equatorial position. The acetoxylmethyl group is in the gauche-gauche conformation. The S atom is in synperiplanar conformation, while the N-C-N-C linkage is antiperiplanar. The N-H•••O intermolecular hydrogen bonds link the molecules into infinite chains and these are connected by C-H•••O interaction.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1076-1080

 

La(III) complex of phenanthroline bridging polyamine as efficient catalyst for thehydrolysis of ATP

Yanhe Guo, Qingchun Ge, Hai Lin, Huakuan Lin* & Shourong Zhu

 

The hydrolysis of ATP catalyzed by protonated ligand 2, 9-di[(2-ethylamino)ethylene-aminomethyl]-1, 10-phenanthroline• 4HCl • H2O(L) or its La(III) complex has been studied at pH 7.6 using 31P NMR spectroscopy. The two systems have a rate of 12.110-4 mol.dm-3 and 15910-4 mol.dm-3, which is about 5- and 59-fold as fast as that of free ATP respectively. La(III) complex of L is a more efficient catalyst for ATP hydrolysis than metal ion alone, which has a rate enhancement ratio about 5. High catalytic efficiency has been achieved through the effective activation of ATP by La(III) complex and the availability of a good intramolecular nucleophile. The phosphoramidate intermediate at 2.88 ppm in L/ATP system has not been observed in La(III)/L/ATP system. The mechanism for ATP hydrolysis catalyzed by complex of “hard” metal ion has been given. The effects of metal ion mediated by polyaza ligand in controlling the recognition of the substrate and the attacking on phosphorous center have been discussed.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1081-1085

 

 

Spectrophotometric determination of protonation constant of
N–phenylbenzohydroxamic acid in mineral acids

Kallol K Ghosh* & Pankaj Tamrakar

 

The UV spectra of N–phenylbenzohydroxamic acid (C6H5CON(OH)C6H5) in sulphuric, perchloric and hydrochloric acid solutions have been analyzed by the characteristic vector method in order to separate protonation from the medium effect. Using the first vector coefficient values, protonation constant (pKBH+) and solvation parameters have been estimated. In the high acidity range, results obtained according to the Cox–Yates excess acidity function, Marziano Mc function, Bunnett–Olsen and Hammett–acidity function methods are in good agreement.

 

 

 

Indian Journal of Chemistry

Vol. 42A, May 2003, pp. 1086-1088

 

 

Determination of Ni(II) and Co(II) by FAAS after preconcentration on modified alumina column

Farzaneh Shemirani*, Reyhaneh Rahnama Kozani, Masood Salavati Niasari,

Shiva Dehghan Abkenar, Mohammad Reza Jamali & Aazam Alsadat Mirroshandel

 

A method for the determination of Co(II) and Ni(II) by flame atomic absorption spectrometry after preconcentration on a minicolumn of alumina modified with sodium dodecyl sulfate and schiff’s base has been developed. Effects of pH, flow rate, volume of sample solution, capacity of sorbent and interference of foreign ions on the recovery of the analytes have been investigated.Under the optimized conditions (pH = 5; flow rate =15 mlmin-1), recovery was greater than 98%. The relative standard deviations (10 replicate analyses) at the 50 ngml-1 level are 2.5% for Ni(II) and 3.2% for Co(II) and the corresponding limits of detection (3s, n =10) are 0.014 ngml-1 for Ni(II) and 0.007 ngml-1 for Co(II). The method has been applied for the determination of Ni(II) and Co(II) in natural waters and standard materials.