Indian Journal of Chemistry
Sect. A: Inorganic, Bio-inorganic, Physical, Theoretical & Analytical

 

VOLUME 41A

NUMBER 6

June 2002

CONTENTS

Papers

 

1107

 

Strengthening of the intramolecular O….H…N hydrogen bond in 2-(N-benzyl-a-iminoethyl)-naphthol as a result of steric repulsion

 

 

 

A Mandal, A Koll, A Filarowski &

S Mukherjee*

 

 

 

A new ortho-hydroxy schiff base 2-(N-benzyl-a-iminoethyl)-naphthol in which the hydrogen atom in the C-C(H)=N group is replaced by a methyl substituent, is synthesized. The O...N distance found in the O….H…N hydrogen bond is quite short and this is due to the steric repulsion of methyl substituent.

 

1112

 

The solvent activity-composition correlation for systems continuously miscible from molten salt to dilute solution

 

 

 

 

Pramod D Sonawane & Anil Kumar*

 

 

 

A new equation has been proposed to correlate the solvent activity-composition data for a variety of systems containing fused salts. The proposed equation comprising the contributions due to long-range and short-range interaction forces is capable of correlating the solvent activities for several systems, including mixtures showing strong negative, positive and weak deviations from Rauolt’s law.

 

 

1120

 

Ion association and solvent interaction–conductance of 1-ethyl-4-cyanopyridinium iodide in aqueous-binary mixtures containing acetone and 1,4-dioxane at different temperatures

 

 

 

Ajay Mukhopadhyay & Mohan Pal*

 

 

 

Conductance of 1-ethyl-4-cyanopyridinium iodide has been measured in binary solvent mixtures of water and aprotic cosolvents at different temperatures. In the water-rich region, water molecules become less available for solvation owing to self association through H-bonding. The preferential solvation of the solute in water + acetone mixture is governed by both specific and nonspecific interaction.

 

 

 

1126

 

 

 

Thermodynamics of interaction between
L-cystine and sodium/magnesium chloride in aqueous solution

 

 

 

Dacheng Li, Qingjiang Yu, Yong Wang & Dezhi Sun*

 

 

Interactions of L-cystine with sodium chloride and magnesium chloride have been studied by determining the solubility of cystine in aqueous salt solutions of different concentration at varying temperatures. The results show that both NaCl and MgCl2 in water is beneficial to dissolution of L-cystine.

 

1131

 

Partial molar volumes of transfer of some disaccharides from water to aqueous guanidine hydrochloride solutions at 298.15 K

 

 

T S Banipal*, Damanjit Kaur,

Gagandeep Singh, B S Lark & P K Banipal

 

 

Apparent molar volumes of D(+)-maltose monohydrate, D(+)-cellobiose, D(+)-lactose monohydrate and D(+)-trehalose dihydrate have been determined in water and aqueous guanidine hydrochloride solutions from density measurements. The results show that hydration behaviour of saccharides do not depend only on constituting subunits but also on the linkage between them.

 

1139

 

Viscometric studies for some 1:1 electrolytes in water + tert-butyl alcohol and water + tert-butylamine mixtures at 298.15 K

 

 

 

 

 

 

Pius K Kipkemboi* & Allan J Easteal

 

 

 

Viscosity and density measurements for NaI, KI, Bu4NI, LiCl and KCl in various mixtures of water with tert-butyl alcohol and tert-butylamine have been carried out. The values of B coefficient for KCl exhibit a minimum in the water-rich region for both systems. For NaI and KI, they are significantly reduced in tert-butylamine-rich mixtures while in tert-butyl alcohol-rich mixtures they increase profoundly compared to water-rich mixtures.

 

1146

 

Synthesis and characterization of some lanthanoid complexes of salicylaldehyde

salicyloyl hydrazone

 

 

 

 

 

 

 

T R Rao*, Sabita Shrestha, & K K Narang

 

 

 

 

1152

 

Synthesis and spectroscopic studies on platinum(II) complexes of thiosemicarbazone derivatives of p-anisaldehyde, p-tolualdehyde and p-vanillin

 

 

 

 

 

 

 

Narayan T Akinchan* & Richa Akinchan

 

 

1157

 

Heterobimetallic chemistry: Heterobimetallic complexes derived from monometallic copper(II) complex of bis(2-hydroxy-1-naphthaldehyde) malonoyldihydrazone

 

 

 

 

R A Lal*, J Chakraborty, S Bhaumik &

A Kumar

 

 

 

Notes

 

1163

 

 

 

QSAR study on antiviral activity of ester prodrugs of 6-methoxypurine arabinosides

 

 

 

Vijay K Agrawal, Ruchi Sharma &

P V Khadikar*

 

 

 

The varicella-zoaster antiviral activity of 6-methoxy purine arabinosides has been modelled using simple as well as multi-variate regression analysis. The predictive potential of the model is discussed on the basis of cross-validation parameters.

 

 

 

1167

 

 

Thermodynamics of molecular interactions in mixtures containing ether

 

 

 

V K Sharma* & Romi

 

 

 

Molar excess volumes, VE and molar excess enthalpies, HE, have been determined for 1,3-dioxolane + benzene or toluene or + -o, or + -p or + m - xylene binary mixtures at 298.15K. The observed data have been analysed in terms of the Graph-theoretical approach, Flory’s approach and Sanchez and Lacombe’s theory.

 

 

1173

 

Surface tension studies of ternary system: Copper soap plus benzene plus methanol at 313K

 

 

V P Mehta, P R Talesara, Rashmi Sharma*, Antima Gangwal & Renu Bhutra

 

 

 

Colloidal behaviour of copper soap solution in benzene plus methanol mixture from the surface tension studies confirm that cmc values depend upon the composition of the solvent mixture and are found to decrease with increase in chain length of the soap anion.

 

1177

 

Oxidative dehydrogenation of ethylbenzene over La and Dy supported vanadia

 

 

 

 

S Sugunan* & N K Renuka

 

 

A series of supported vanadia systems have been prepared by excess solvent technique using La2O3 and Dy2O3 as supports. The oxidative dehydrogenation of ethylbenzene has been employed as a chemical probe reaction to examine the catalytic activity. The active species correspond to amorphous and crystalline tetrahedral vanadyl units in the supported system.

 

1184

 

 

Determination of osmotic coefficients of aqueous solutions of polyhydroxylated compounds at various temperatures

 

 

 

 

Zuo-Ning Gao* , Jin-Fu Li & Xiao-Lin Wen

 

 

 

Osmotic coefficients of aqueous solutions of glycol, glycerol, sucrose and glucose at various temperatures have been determined. The relation between the experimental results of the molal osmotic coefficients and the molal concentration of the solution are in agreement with that from the polynomial fitting at various temperatures. The molar osmotic coefficients increase with increase in concentration of solutes.

 

 

1188

 

Kinetics and mechanism of the interaction of thiosemicarbazide with di-m-hydroxo bis(bipyridyl)dipalladium(II) ion

 

 

 

 

 

 

 

 

Sankar Chandra Moi, G S De & A K Ghosh*

 

 

1191

 

Kinetics and mechanism of the reaction of hydroxopentaaquarhodium(III) ion with
l-aspartic acid in aqueous media

 

 

 

 

 

S Mohanty, S Anand & P Mohanty*

 

 

 

Kobs

HL- +[Rh (OH2)5OH]2+      [Rh(OH2)5OH]2+ , HL-.

                                                  

 

 kan

 [Rh(OH2)5OH]2+ .HL-      [Rh(OH2)4(OH)HL]+ + H2O

slow

 

 fast

[Rh (OH2) 4(OH) HL]+       [Rh (OH2) 3(OH) L] +H2O

Chelation

 

1195

 

 

Kinetic and mechanistic investigation of the reaction of cis-diaqua-bis(ethylenediamine) cobalt(III) with glycylglycine in
aqueous solution

 

 

Debabrata Chatterjee* & Biswajit Ruj

 

 

 

 

 

1199

 

The crystal structure and spectroscopic studies of iron(III)tris(8-quinolinolato-N,O) [Fe(C9H6NO)3]C2H5OH complex

 

 

 

 

 

 

Shusheng Zhang, Jingbo Xue &

Fangfang Jian*

 

 

 

1202

 

Cation-p interactions: Synthesis and crystal structure of complex [K(DB18C6)]I3

 

 

 

 

 

 

 

Qingjiang Yu, Tong Wang, Jianmin Dou*,

Dacheng Li & Daqi Wang

 

 

 

1205

 

Spectral and thermal studies of
homodinuclear and heterodinuclear
glutathione complexes

 

 

Bhagwan S Garg*, Deo Nandan Kumar &

B K Singh

 

 

 

The complexes of the types [M2LSO4.2H2O] where L=GSH, M = Co(II), Cu(II), Zn(II), Cd(II) and [MM'LSO4.2H2O] where L = GSH, M = Cu(II), M' = Zn(II) & M = Co(II), M' = Cd(II)] have been synthesized and characterized.

 

1208

 

A study of the under potential deposited hydrogen on the nickel deposited electrode in alkaline media

 

 

M Jafarian* , M G Mahjani , M Hoseni &

F Gobal

 

 

 

Hydrogen evolution reaction has been studied on the nickel deposited electrode. The sodium ion has no effect on the hydrogen evolution reaction. The diffusion coefficient of hydrogen is calculated to be D=2.88x10-10 cm2s-1 using impedance technique.

 

 

1212

 

Silica enriched faujasitic zeolite-Y from flyash

 

 

S U Meshram, S S Rayalu*, K N Munshi &

M Z Hasan

 

 

 

 

Various process modifications to enrich silica on zeolite-Y have been carried out by increasing substantially the SiO2/Al2O3 ratio from 1.8-2.0 to 2.5-3.0 with consequent increase in thermal stability.

Authors for correspondence are indicated by (*)

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1107-1111

 

Strengthening of the intramolecular O¼H…N hydrogen bond in
2-(N-benzyl-
a-iminoethyl)-naphthol as a result of steric repulsion

A Mandal, A Koll, A Filarowski & S Mukherjee*

One new ortho-hydroxy Schiff base, 2-(N-benzyl-a-iminoethyl)-naphthol (BEIN) in which the hydrogen atom in the C-C(H)=N group is replaced by a methyl substituent, is synthesized. The crystal structure is determined and ab initio calculations with B3LYP/6-31G** basis sets are performed. The O…N distance found in the O-H…N hydrogen bond turns out to be quite short and is equal to 2.499 Å. This shortening is due to the steric repulsion of methyl substituent group and results in strengthening of the hydrogen bond.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1112-1119

 

The solvent activity-composition correlation for systems continuously miscible from molten salt to dilute solution

 

Pramod D Sonawane & Anil Kumar*

 

The systems, which are continuously miscible from pure fused ionic solute to dilute solutions in aqueous or non-aqueous phase, exhibit some interesting physical properties. The composition dependence of solvent activity in these systems resembles that of non-electrolyte mixtures. A new equation has been proposed to correlate the solvent activity-composition (a1-x1) data for a variety of systems containing fused salts. The proposed equation comprises the contributions due to long-range (a modified Debye-Huckel term) and short-range (an empirical expression) interaction forces. The equation is capable to correlate the solvent activities, a1 for the systems showing strong negative, positive and weak deviations from Rauolt’s law. The correlative power of the proposed equation has been tested against 13 systems showing negative deviations, 4 systems showing positive deviations from Rauolt’s law and 7 mixtures. These systems are continuously miscible from pure fused salt to dilute solutions. The performance of our equation has been compared to some existing models available in literature.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1120-1125

 

Ion association and solvent interaction–conductance of 1-ethyl-4-cyano pyridinium iodide in aqueous-binary mixtures containing acetone and 1,4-dioxane at different temperatures

 

Ajay Mukhopadhyay & Mohan Pal*

 

 

Conductance of 1-ethyl-4-cyanopyridinium iodide has been measured in the concentration range (7.8-19.1) ´ 10-4 mol dm-3 in binary solvent mixtures of water and aprotic cosolvents (acetone and 1,4-dioxane) at different temperatures (293-308 K). The conductance data in all cases have been analysed by the Shedlovsky equation to obtain L0 and KA. Based on the composition dependence of Walden product, the influence of the mixed solvent composition on the solvation of ions has been discussed. The association constants, KA, are used to get information about the influence of solvent composition on the various equilibria present in the solution. Thermodynamic parameter, DH0, as a function of solvent composition has also been determined.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1126-1130

 

Thermodynamics of interaction between L-cystine and sodium/magnesium chloride in aqueous solution

Dacheng Li, Qingjiang Yu, Yong Wang & Dezhi Sun*

 

Interactions of L-cystine with sodium chloride and magnesium chloride have been studied by determining the solubility of cystine in aqueous salt solutions of different concentration at varying temperatures. The interaction thermodynamic parameters have been estimated with the solubility data. The results show that both NaCl and MgCl2 in water is beneficial to dissolution of L-cystine. Enthalpy or entropy of interaction between L-cystine and NaCl is negative while that between L-cystine and MgCl2 is positive. These interesting results are discussed in the light of static electricity theory as well as hydration of ions.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1131-1138

Partial molar volumes of transfer of some disaccharides from water

to aqueous guanidine hydrochloride solutions at 298.15 K

T S Banipal*, Damanjit Kaur, Gagandeep Singh, B S Lark & P K Banipal

 

Apparent molar volumes (fv) of some disaccharides [D(+)-maltose monohydrate, D(+)-cellobiose, D(+)-lactose monohydrate and D(+)-trehalose dihydrate] have been determined in water and in aqueous guanidine hydrochloride solutions (0.5, 1.0, 4.0, 6.0 and 8.0 m) at 298.15 K from density measurements using a vibrating-tube digital densitometer. Partial molar volumes at infinite dilution (Vo2) determined from fv values have been utilised to estimate partial molar volumes of transfer (Vo2,tr) for various disaccharides from water to aqueous guanidine hydrochloride solutions. The Vo2,tr values have been found to be positive for all the disaccharides and increase with the increase in the concentration of the co-solute which suggest that overall structural order is enhanced in aqueous guanidine hydrochloride solutions. The Vo2,tr values have been rationalized in terms of solute-co-solute interactions using co-sphere overlap hydration model. Pair, triplet and quartet interaction coefficients have also been calculated using McMillan-Mayer approach and their sign and magnitude have also been discussed

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1139-1145

 

Viscometric studies for some 1:1 electrolytes in water + tert-butyl alcohol and water + tert-butylamine mixtures at 298.15 K

Pius K Kipkemboi* & Allan J Easteal

 

Viscosity and density measurements for NaI, KI, Bu4NI, LiCl and KCl in various mixtures of water with tert-butyl alcohol and tert-butylamine were carried out at 298.15 K. The viscosity data have been analysed on the basis of the Jones-Dole equation and viscosity B-coefficients have been evaluated. The small and positive values of B coefficients for LiCl in mixed liquid solvents as observed in both systems lead to the conclusion that ion-solvent interaction is not strong. The B coefficients for hydrophobic Bu4NI are large, positive and fairly constant for both systems probably due to the absence of specific hydration and solvation effects. The values of B coefficient for KCl exhibit a minimum in the water-rich region for both systems. However, the solvent composition dependence of B coefficients for both NaI and KI electrolytes are drastically different in the two solvent systems. The viscosity B coefficients for NaI and KI are significantly reduced in tert-butylamine-rich mixtures while in tert-butyl alcohol-rich mixtures they increase profoundly compared to water-rich mixtures. Values of the partial molar volumes of the electrolytes at infinite dilution in the various solvent mixtures have been evaluated from the density measurements.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1146-1151

 

Synthesis and characterization of some lanthanoid complexes of salicylaldehyde salicyloyl hydrazone

 

T R Rao* , Sabita Shrestha & K K Narang

 

Some Lanthanoid complexes of the types, [Ln(ssh)(H2O)n].H2O and [Ln'(Hssh)(X)(H2O)3].H2O, where Ln = Y, La, Nd, Gd, Tb and Dy; Ln' = Pr/Sm for X =  NO3/Cl and H3ssh = salicylaldehyde salicyloyl hydrazone, have been synthesized and characterized by elemental analyses, molar conductance, magnetic susceptibility, infrared, electronic and 1H NMR spectral data.  Selected complexes have also been studied on the basis of their solid state electrical conductivity, band gap, and powder X-ray diffraction data.  The complexes, except those of the Pr and Sm, are polymeric in nature showing high decomposition points.  Dehydration study indicates the presence of water molecules both in the lattice and coordination sphere of the complex metal ions.  IR and 1H NMR spectral data suggest trinegative tetradentate and dinegative tridentate coordination of H3ssh in the complexes.  The chloro and nitrato groups were found to coordinate to the metal ion as monodentate and bidentate-chelating species respectively.  Solid state electrical conductivity data at various frequencies show semi-conducting nature of the complexes.  Optical band gap studies show the complex [Gd(ssh)(H2O)3].H2O to be a direct band gap semi-conducting material with a band gap of 2.64 eV.  Powder X-ray diffraction patterns show orthorhombic structure for most of the complexes.  Various polyhedral geometries such as distorted octahedron, pentagonal bipyramid and distorted square antiprism were tentatively proposed for the complexes.

 

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1152-1156

 

 

Synthesis and spectroscopic studies on platinum(II) complexes of thiosemicarbazone derivatives of p-anisaldehyde, p-tolualdehyde and p-vanillin

 

Narayan T Akinchan* & Richa Akinchan

 

The platinum(II) complexes of thiosemicarbazone derivatives of p-anisaldehyde (ATSCH), p-tolualdehyde (TTSCH) and p-vanillin (VTSCH) have been prepared and characterized by analytical, molar conductance, infrared, electronic, 1H and 13C NMR spectral data. Thiosemicarbazones exist in thione form and coordinate through thiolato/thione sulphur and azomethine nitrogen. The chloro bridged dinuclear structures for [Pt(ATSC)Cl]2, [Pt(TTSC)Cl]2 and [Pt(VTSC)Cl]2 having four coordinate platinum(II) centres and square planar for [Pt (ATSCH)2]Cl2, [Pt(TTSCH)2]Cl2 and (Pt(VTSCH)2Cl2 are suggested.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1157-1162

 

Heterobimetallic chemistry : Heterobimetallic complexes derived from monometallic copper(II) complex of bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone

R A Lal*, J Chakraborty , S Bhaumik & A Kumar

 

Monometallic copper(II) complex [Cu(LH2)(H2O)2] ( 1) and heterobimetallic complexes [MCu(L)(H2O)3] (where M = UO2(2) and Zn(4)) and [MCu(L)(H2O)4] (where M = MoO2(3), Ni(5), Co(6) and Mn(7)) and homobimetallic copper(II) complex [Cu2(L)(H2O)4].2H2O(8) have been isolated and characterized by analytical, molecular weight, magnetic moment, electrical conductance, electronic ir and esr spectral data. IR spectral evidences indicate that dihydrazone coordinates to the metal centres in enol forms. The monometallic copper(II) complex (1) and the heterobimetallic complexes UO2Cu (2) and MoO2Cu (3) and Zn-Cu (4) are normal paramagnetic indicating absence of any metal-metal interaction in the structural unit of the complexes while the remaining heterobimetallic complexes Ni-Cu(5), Co-Cu (6) and Mn-Cu (7) have much less meff values than those required for 3, 4 and 6 unpaired electrons indicating considerable metal – metal interactions. Copper has distorted octahedral geometry in monometallic and heterobimetallic complexes. Uranium has pentagonal bipyramidal stereochemistry while zinc has square pyramidal stereochemistry. However, copper(II) has square pyramidal stereochemistry in homobimetallic complex (8).

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1163-1166

 

QSAR study on antiviral activity of ester prodrugs of

6-methoxypurine arabinosides

 

Vijay K Agrawal,  Ruchi Sharma  & P V Khadikar*

 

The varicella-zoaster antiviral activity of 6-methoxy purine arabinosides has been modelled using simple as well as multi-variate regression analysis. Excellent results are obtained in curvilinear regression. The predictive potential of the model is discussed on the basis of cross-validation parameters.

 

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1167-1172

 

 

 

Thermodynamics of molecular interactions in mixtures containing ether

 

V K Sharma* & Romi

 

Molar excess volumes, VE and molar excess enthalpies, HE, for 1,3-dioxolane(i) + benzene or toluene or + -o, or + -p or +m - xylene(j) binary mixtures have been measured by dilatometer and microflow calorimeter as a function of composition at the temperature 298.15K. The observed data have been analysed in terms of (i) the Graph-theoretical approach, (ii) Flory’s approach and (iii) Sanchez and Lacombe’s theory. The analysis of VE data by Graph-theoretical approach suggest that various (i+j) mixtures are characterized by interactions between delocalised p-electron cloud of aromatic ring of aromatic hydrocarbons and p electrons of oxygen atoms in 1, 3-dioxolane. The IR studies lend further credance to the nature and extent of interactions with support for the proposed structures in studied mixtures. It has also been observed that VE and HE data calculated by Graph theory compare well with their experimental values.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1173-1176

 

 

Surface tension studies of ternary system: Copper soap plus benzene plus methanol at 313 K

V P Mehta, P R Talesara, Rashmi Sharma*, Antima Gangwal & Renu Bhutra

 

Colloidal behaviour of copper soap solution in benzene plus methanol mixture from the surface tension studies confirms that cmc values depend upon the composition of the solvent mixture and are found to decrease with increase in chain length of the soap anion. The results of the surface tensions have been explained on the basis of Szyszkowski’s empirical equation and it is observed that the values X, Y, and (-X ln Y) lead to the confirmation of the fact that the change in the behaviour of the soap takes place at 50% methanol concentration. The plots of the parachor against the mole fraction of the soap are characterised by an intersection of two straightlines at the cmc of the soap. Hammic and Andrew’s equation has been successfully applied to explain the behaviour of soap in benzene-methanol mixture.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1177-1183

 

 

Oxidative dehydrogenation of ethylbenzene over La and Dy supported vanadia

S Sugunan* & N K Renuka

 

A series of supported vanadia systems have been prepared by excess solvent technique using La2O3 and Dy2O3 as supports. Physical characterization has been carried out using XRD, FTIR, TG studies, BET surface area measurement, pore volume analysis etc. Cyclohexanol decomposition has been used as a test reaction for evaluating the acid base properties of the supported system. The oxidative dehydrogenation of ethylbenzene has been employed as a chemical probe reaction to examine the catalytic activity. The active species correspond to amorphous and crystalline tetrahedral vanadyl units in the supported system.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1184-1187

 

 

Determination of osmotic coefficients of aqueous solutions of polyhydroxylated compounds at various temperatures

Zuo-Ning Gao*,  Jin-Fu Li &  Xiao-Lin Wen

 

Osmotic coefficients of aqueous solutions of polyhydroxylated compounds such as glycol, glycerol, sucrose and glucose at various temperatures over the concentration range of 0.0 ~ 2.1 mol kg-1 and 0.0 ~ 2.0 mol kg-1 have been determined, respectively. Using a linear least-squares fitting routine, the osmotic coefficients have been fitted by a simple polynomial equation. It is found that the relation between the experimental results of the molal osmotic coefficients F and the molal concentration of the solution m are in agreement with that from the polynomial fitting at various temperatures. The experimental results also show that over the studied concentration range and at various temperatures, the molar osmotic coefficients of aqueous solutions increase with increase in concentration of solutes. The aqueous glycol solution system exhibits the properties of the ideal solution.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1188-1190

 

 

Kinetics and mechanism of the interaction of thiosemicarbazide with di-m-hydroxo bis(bipyridyl)dipalladium(II) ion

Sankar Chandra Moi,  A K Ghosh* &  G S De

 

Kinetics of interaction between thiosemicarbazide with the title complex has been studied spectrophotometrically as a function of [Pd2(bipy)2(OH)22+], [thiosemicarbazide], pH and temperature. The reaction has been monitored at 280 nm, the lmax of the substituted complex, where the spectral difference between the reactant and the product is maximum. The reaction rate increases linearly with increase in [thiosemicarbazide]. The second order rate constants have been calculated from the slope of the kobs versus [ligand] plot. From the experimental findings an associative mechanism for the substitution process is suggested. The activation parameters (DH¹ = 50.4 ± 1.9 kJ mol-1, DS¹ = -105 ± 6 J K-1 mol-1) also support the proposition.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1191-1194

 

Kinetics and mechanism of the reaction of hydroxopentaaquarhodium(III) ion with l-aspartic acid in aqueous media

 

S Mohanty,  S Anand & P Mohanty*

 

The kinetics of the reaction of l-aspartic acid (H3L+) with hydroxopentaaquarhodium (III) has been studied over the range 2.58≤103[H3L+] ≤12.90, 3.49 ≤pH≤ 4.3, 50°t ≤65°C and I=0.1mol dm-3(NaClO4).The reaction takes place via an outer sphere association between RhOH2+ and (H3L+) followed by transformation of the outer into an inner-sphere complex (chelate is formed) by slow interchange. The anation rate constant RhOH3+ at 25°C and I= 0.1mol dm- (NaClO4) is found to be 2.2´10-6s–1. ∆H# and ∆S# for kan path are found to be 62.0±1.2 kJ mol-1 and –120.8 ±3.4 JK-1mol-1 respectively. Anation reaction of RhOH2+ follows an Ia path.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1195-1198

 

Kinetic and mechanistic investigation of the reaction of cis-diaqua-bis(ethylenediamine) cobalt(III) with glycylglycine in aqueous solution

 

Debabrata Chatterjee* & Biswajit Ruj

The reaction of cis-[Co(en)2(H2O)2]3+ (complex-1) with glycylglycine (gly.gly) resulted in the formation of a mixed-chelate cis-[Co(en)2(gly.gly)]2+ product (complex-2). The kinetics of the reaction has been studied spectrophotometrically as a function of [complex-1], [gly.gly], pH, ionic strength (ClO4- and NO3-) and temperature (25-55°C). Kinetic data and activation parameters are compared to all available literature information which confirms the proposed conventional dissociative interchange mechanism involving pre-association of complex-1 ion and gly.gly species in the present reaction.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1199-1201

 

The crystal structure and spectroscopic studies of iron(III)tris(8-quinolinolato-N,O), [Fe(C9H6NO)3]C2H5OH complex

 

Shusheng Zhang, Jingbo Xue & Fangfang Jian*

 

The crystal and molecular structure of the complex [Fe(Quin)3]C2H5OH [Quin = 8-hydroxyquinoline-N,O] has been determined by X-ray crystallography. The complex crystallizes in the monoclinic system, space group Pn, with lattice parameters a = 11.229(2), b = 13.483(3), c = 16.753(3) Å, b=94.35(3)° and Z = 4. The central Fe atom is coordinated octahedrally with the three N atoms and three O atoms from three 8-quinolinolato ligands. The three Fe-O bonds distances are in the range of 1.963(11)-2.013(9)Å, while the three Fe-N bond distances range from 2.114(11)-2.253(9)Å. In the solid state, the ligand and the ethanol moiety form one-dimensional hydrogen bonds network through O(1)...H-O(4) intermolecular hydrogen bond.

 

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1202-1204

 

Cation-p interactions: Synthesis and crystal structure of complex [K(DB18C6)]I3

Qingjiang Yu, Tong Wang , Jianmin Dou*, Dacheng Li  & Daqi Wang

 

A dibenzo-18-crown-6 (DB18C6) complex, [K(DB18C6)]I3 has been isolated and characterized by elemental analysis, IR and X-ray diffraction analysis. The complex belongs to triclinic, space group P21/c with cell dimensions, a = 0.97870(17), b = 1.6909(3), c = 1.5435(3) nm, b = 98.435(3)º, V = 2.5266(7) nm3, Z = 2, Dcalc. = 1.026 Mg/m3, F(000) = 740, R1 = 0.0534 and wR2 = 0.1666. In the solid state, two [K(DB18C6)]+ complex cations form a dimeric structure bridged by K+-p interactions.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1205-1207

 

 

Spectral and thermal studies of homodinuclear and heterodinuclearglutathione complexes

Bhagwan S Garg*, Deo Nandan Kumar & B K Singh

 

The complexes of the types [M2LSO4.2H2O] where L=GSH, M = Co(II), Cu(II), Zn(II), Cd(II) and [MM'LSO4.2H2O] where L = GSH, M = Cu(II), M' = Zn(II) and M = Co(II), M' = Cd(II)] have been prepared and characterized by elemental analysis, magnetic susceptibility measurements, IR, EPR, electronic spectral studies and thermal analysis. Deprotonation and coordination of thiol group occurs and glycine residue binds with the metal ions in all the complexes. Copper(II) and cobalt(II) complexes show low magnetic moment. EPR spectral data show that complexes have planar geometry. Ligand to metal charge transfer are observed in all the complexes and d-d transition are also observed in copper(II) and cobalt(II) complexes. Thermal decomposition of all the complexes proceeds via first order kinetics.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1208-1211

 

 

A study of the underpotential depositedhydrogen on the nickel deposited electrode in alkaline media

M Jafarian*, M G Mahjani,  M Hoseni & F Gobal

 

Hydrogen evolution reaction has been studied on the nickel deposited electrode. Two reduction peaks at –1V/Ag-AgCl and –1.3V/Ag-AgCl and one oxidation peak at –1.3V/Ag-AgCl have been observed. Shift due to oxidation peak arises from change of cathodic limit, attributed to the two competitive reactions on the surface. The peak located on the more anodic side is due to the oxidation of HUPD and the second peak due to the oxidation of HOPD. The sodium ion has no effect on the hydrogen evolution reaction. The diffusion coefficient of hydrogen is calculated to be D=2.88×10-10 cm2s-1using impedance technique.

 

Indian Journal of Chemistry

Vol. 41A, June 2002, pp. 1212-1216

 

 

 

Silica enriched faujasitic zeolite-Y from flyash

 

S U Meshram, S S Rayalu*, K N Munshi & M Z Hasan

 

 

Various process modifications to enrich silica in zeolite-Y have been carried out by increasing substantially the SiO2 /Al2O3 ratio from 1.8-2.0 to 2.5-3.0 with consequent increase in thermal stability. Some new phases of zeolites have been observed with improved silica alumina ratio up to 3.0 to 3.5. Crystallinity has been monitored by XRD analysis, ranging from 70-99% for different samples