Indian Journal of Chemistry

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

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VOLUME 45A

NUMBER 12

DECEMBER 2006

CONTENTS

Papers

 

2591

 

Excess adsorption on hydrophobic and hydrophilic solid-liquid interfaces. Positive excess adsorption of non-ionic surfactant. Part 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ebrahim Halder, D K Chattoraj* & K P Das

 

 

 

 

The extent of adsorption  of non-ionic surfactant Tween-20 onto hydrophilic alumina and silica and hydrophobic charcoal surfaces has been measured as a function of surfactant concentration at different temperatures.

 

 

2599

 

Excess adsorption on hydrophobic and hydrophilic solid-liquid interfaces: Negative adsorption of electrolyes and urea. Part 2

 

 

 

 

Ebrahim Halder, D K Chattoraj* & K P Das

 

 

 

 

The extent of hydration of charcoal and cationic and anionic resin powders in the presence and absence of some inorganic salts and urea has been studied using isopiestic vapour pressure technique. The shapes of water vapour adsorption isotherms for different solids agree with type III BET isotherms. At water activity approaching unity, maximum values of water adsorption at 30°C are in the order: cationic resin > anionic resin > charcoal.

 

2607

 

Single-ion transfer Gibbs energies in binary mixtures of isodielectric protic ethylene glycol and dipolar aprotic N,N-dimethyl formamide

 

 

 

 

B K Dolui, S K Bhattacharya* & K K Kundu*

 

 

 

 

Single-ion transfer Gibbs energies, ∆G0t(i) of some electrolytes like tetraphenylarsonium picrate, potassium tetraphenylborate, potassium picrate  and potassium chloride  from protic ethylene glycol to isodielectric mixtures of ethylene glycol and dipolar aprotic DMF with 20, 40 and 60 wt.% DMF compositions have been determined at 25°C by measuring solubility of the salts at 25°C and using the widely accepted TATB reference electrolyte assumption. The results reveal that increased cationophilicity, anionophobicity, dispersion interaction and aproticity of the solvent mixtures guide the solvation behaviour of the ions.

 

 

2615

 

Spectrochemical properties of
2,3-dihydronaphtho[1,8-de][1,2]diazepine-1,4-dione and its derivatives

 

 

 

 

 

N V KrishnaMurthy & A Ram Reddy *

 

 

 

 

The electronic absorption and fluorescence spectral studies of 2,3-dihydronaphtho[1,8-de][1,2]diazepine-1,4-dione and its derivatives are investigated in various solvents. The amino group facilitates the formation of a solvent sensitive intramolecular charge transfer band, which makes it a better fluorophore.

 

Notes

 

2624

 

Non-linear behaviour of smectic C phase in binary systems

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Vandana Gupta & Rajinder K Bamezai*

 

 

 

 

Phase diagrams of binary mixtures of 4-n-alkyloxy phenyl-4´-n-alkyl cyclohexyl carboxylate (I) and
2,3-difluoro-4-n-octyloxy-4-[4-n-pentyl cyclohexyl]-phenyl benzoate (II) are described in which a discontinuous behaviour of smectic C phase belonging to II is observed by changing the polymorphic behaviour of compounds from the homologous series I.
One of the chosen components shows a rich polymorphism existing either in nematic or nematic with smectic A and smectic B phases. An enhancement in smectic A phase has been observed between two components selected from this series. The other component which shows nematic and smectic C phases undergoes non-linear variation in smectic C-nematic transition curve.

 

 

 

2628

 

Kinetics and binding studies on the reaction of cyanopropyl(aquo)cobaloxime with CT-DNA and amines

 

 

 

 

 

 

P Pallavi, Penumaka Nagababu, J Naveena Lavanya Latha & S Satyanarayana*

 

 

 

 

The ligand substitution reactions of cyanopropyl (aquo) cobaloxime have been studied with various amines such as methylamine, ethylamine, butylamine, pentylamine, hexylamine, cyclopropylamine, cyclohexylamine and cyclopentylamine, as entering nucleophiles. The entering nucleophile displaces the molecule trans to the cyanopropyl group to form the six-coordinated complex, [CNCH2CH2CH2Co(DH)2L]. Study shows that the entering nucleophile participates in the transition state, and hence, an SN1 mechanism is proposed.

 

 

2632

 

Synthesis, reactions and physico-chemical characterisation of iron (III) complexes containing substituted benzoxazole and various Schiff base moieties

 

 

 

 

 

 

 

 

 

 

 

 

R K Dubey*, U K Dubey & C M Mishra

 

 

 

 

 

 

 

2638

 

Synthesis and spectroscopic characterisation of new types of mixed-ligand homo- and heterobimetallic derivatives of butyltin(IV)

 

 

 

 

 

 

 

 

 

 

 

Nandu Bala Sharma & Anirudh Singh*

 

 

 

 

 

 

2644

 

Synthesis and spectroscopic characterization of mixed ligand complexes of oxovanadium(V)

 

 

 

 

 

 

 

 

Rajendra Singh Ghadwal & Anirudh Singh*

 

 

 

 

 

 

2650

 

Densities, viscosities and excess thermodynamic properties of ternary liquid mixtures of nitrobenzene with polar and non-polar solvents at 298.15 K

 

 

 

 

 

 

 

 

 

Poonam Rathore & Mukhtar Singh*

 

 

 

 

Densities and viscosities of ternary liquid mixtures of nitrobenzene + methyl alcohol + (benzene; + toluene;
+ carbon tetrachloride; + 1,4-dioxane) have been determined at 298.15 K. From these data, viscosity deviations and thermodynamic excess properties, viz., excess molar volume and excess Gibbs free energy of activation of viscous flow for the ternary mixtures have been determined and fitted to Cibulka’s equation. The results show that experimental values of these properties are in close agreement with those predicted by Cibulka’s equation.

 

 

2658

 

Solvent extraction and determination of scandium(III) with Cyanex272 as an extractant

 

 

 

 

 

 

 

Manjusha Karve*  & Bhagyashree Vaidya

 

 

 

 

A novel method for the solvent extraction separation of scandium(III) at pH 5.0 using 5 x 10-4 M Cyanex272 has been developed. Scandium(III) has been stripped from the organic phase with 1.0 M HNO3 and determined spectrophotometrically as its complex with Arsenazo(III) at 675 nm. The method developed is reproducible with a relative standard deviation of 0.4 %.

 

 

2661

 

 

Annual Index

 

 

 

2672

 

Announcement

 

 

 

 

 

Authors for correspondence are indicated by (*)


Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2591-2598

 

Excess adsorption on hydrophobic and hydrophilic solid-liquid interfaces.

Positive excess adsorption of non-ionic surfactant. Part 1

 

Ebrahim Halder, D K Chattoraj* & K P Das

Received 22 September 2005; revised 28 September 2006

The extent of adsorption  of non-ionic surfactant Tween-20 onto hydrophilic alumina and silica and hydrophobic charcoal surfaces has been measured as a function of surfactant concentration (X2) in mole fraction unit at different temperatures. For each isotherm,  at low range of X2 increases with increase in surfactant concentration. But, it reaches maximum  when X2 reaches a critical value . With increase in temperature,  increases for charcoal and silica surfaces while it decreases for alumina surface. At 40°C,  at charcoal surface begins to decrease when X2 exceeds . At 30°C for charcoal surface,  increases sharply with increase in X2 without reaching any limiting value due to the multilayer adsorption of Tween-20. Similar formation of multilayers is also observed at alumina-water interface when the surface coverage is significantly low. Fomation of multilayers of Tween-20 molecules on the surface of silica is not observed even when X2 is relatively high. Using the integrated form of the Gibbs adsorption equation, the standard free energy change  for the adsorption of non-ionic surfactant per square meter of powdered surface due to the change of the bulk activity of Tween-20 from zero to unity has been evaluated and critically examined.

 

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2599-2606

 

Excess adsorption on hydrophobic and hydrophilic solid-liquid interfaces: Negative adsorption of electrolytes and urea. Part 2

Ebrahim Halder, D K Chattoraj* & K P Das

Received  22 September 2005;  revised 28 September 2006

The extent of hydration of charcoal, cationic and anionic resin powders in the presence and absence of some inorganic salts and urea has been studied using isopiestic vapour pressure technique. The shapes of water vapour adsorption isotherms for different solids agree with type III BET isotherms. At water activity approaching unity, maximum values of water adsorption Dn10 in moles per square meter of solid at 30°C are in the order: cationic resin > anionic resin > charcoal. Standard free energies (DG°), of adsorption of water vapour have also been evaluated. The negative and positive excess hydration of these solid powers for different mole fractions of LiCl, NaCl, KCl, Na2SO4 and urea in the bulk phase have been estimated using data obtained from the isopiestic experiments. The free energies of excess hydration for all these systems have been evaluated using the integrated forms of the Gibbs adsorption equations. The absolute values of water and salt binding to these solids have been estimated in the bulk phase.

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2607-2614

 

Single-ion transfer Gibbs energies in binary mixtures of isodielectric protic ethylene glycol and dipolar aprotic N,N-dimethyl formamide

B K Dolui, S K Bhattacharya* & K K Kundu*

Received 14 June 2006; revised 27 September 2006

Single-ion transfer Gibbs energies, ∆G0t(i) of some electrolytes like tetraphenylarsonium picrate, potassium tetraphenylborate, potassium picrate  and potassium chloride  from protic ethylene glycol to isodielectric mixtures of ethylene glycol and dipolar aprotic DMF with 20, 40 and 60  wt.% DMF compositions have been determined at 25°C by measuring solubility of the salts at 25°C and using the widely accepted TATB reference electrolyte assumption. The chemical effects of the transfer Gibbs energies of the ions, ∆G0t, ch(i), have been obtained after correcting for the cavity effects, ∆G0t, cav (i), estimated by the scaled particle theory, the ion-dipole interaction effects, ∆G0t (i-d)(i), estimated by use of Kim formulations and ignoring Born-type electrostatic effect, ∆G0t,Born(i), since the solvent mixtures are isodielectric. The observed results on careful analysis reveal that increased cationophilicity, anionophobicity, dispersion interaction and aproticity of the solvent mixtures are guiding the solvation behaviour of the ions. The study also recognizes ‘solvophobic solvation’ for the large organic ions in ethylene glycol and its mixtures similar to ‘hydrophobic hydration’ in water and its mixtures with other cosolvents.

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2615-2623

 

Spectrochemical properties of 2,3-dihydronaphtho[1,8-de][1,2]diazepine-1,4-dione and its derivatives

N V KrishnaMurthy & A Ram Reddy*

Received 27 January 2006; revised 19 September 2006

The electronic absorption and fluorescence properties of 2,3-dihydronaphtho[1,8-de][1,2]diazepine-1,4-dione (II), 6-nitro-2,3-dihydronaphtho[1,8-de][1,2]diazepine-1,4-dione (III) and 6-amino-2,3-dihydronaphtho[1,8-de][1,2]diazepine-1,4-dione (IV) have been studied in different solvents. The compounds show variation from the characteristic electronic absorption spectra of naphthalene moiety. The electron withdrawing and donating groups in III and IV facilitate longitudinal polarization causing a red shift in the 1Bb and 1Lb transitions. Proton donating solvents cause a blue shift. A new intramolecular charge transfer band is noticed as a result of capdative effect of electron donating amino substituent. The fluorescence studies show that the excitation maximum of III is always closer to that of the absorption maximum, while in IV these are separated indicating that IV undergoes association in the excited state. Stokes shifts for the substituted naphthylhydrazides vary from 33.4 to 133 nm. Compound IV exhibits larger Stokes shifts than compound III. The relative fluorescence intensities and the quantum yields of compound IV are always higher than that of III in the respective solvents. The presence of the electron donating amino group enhances the fluorescence properties of compound IV. The steady state fluorescence properties of these hydrazides do not bear any linear relationship with solvent polarity function. However, a subtle relationship is found to exist when the solvents are categorized into proton donating, accepting and inert solvents, indicating the existence of a specific interaction between the fluorophore and the solvent. Compound IV exhibits a reasonably high lifetime, which is solvent sensitive and is a better fluorophore in comparison to the other hydrazides studied.

 

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2624-2627

 

Non-linear behaviour of smectic C phase in binary systems

Vandana Gupta & Rajinder K Bamezai*

Received 30 December 2005; revised 4 October 2006

The mesophase behaviour has been characterized for binary mixtures formed from components of electron donating substituents. One of the chosen components shows a rich polymorphism existing either in nematic or nematic with smectic A and smectic B phases. An enhancement in smectic A phase has been observed between two components selected from this series. The other component which shows nematic and smectic C phases undergoes non-linear variation in smectic C-nematic transition curve. The phase diagrams have been constructed for the various systems in order to investigate the effect of change of polymorphism.

 

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2628-2631

 

Kinetics and binding studies on the reaction of cyanopropyl(aquo)cobaloxime with CT-DNA and amines

P Pallavi, Penumaka Nagababu, J Naveena Lavanya Latha & S Satyanarayana*

Received 29 March 2006; revised 3 October 2006

The ligand substitution reactions of cyanopropyl (aquo) cobaloxime have been studied with various amines such as methylamine, ethylamine, butylamine, pentylamine, hexylamine, cyclopropylamine, cyclohexylamine and cyclopentylamine, as entering nucleophiles. The entering nucleophile displaces the molecule trans to the cyanopropyl group to form the six-coordinated complex, [CNCH2CH2CH2Co(DH)2L]. The rate constants have been determined by varying the pH and concentration of the ligand under pseudo first order conditions. Equilibrium constants have been determined as a function of pH, for the binding of amines to [CNCH2CH2CH2Co(DH)2L]. Study shows that the entering nucleophile participates in the transition state, and hence, SN1 mechanism is proposed. Antimicrobial activity of cyanopropyl(aquo)cobaloxime on E. coli has been studied. The interaction of cyanopropyl(aquo) cobaloxime with CT DNA has been studied spectrophotometrically and binding constant has been calculated.

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2632-2637

 

Synthesis, reactions and physico-chemical characterisation of iron(III) complexes containing substituted benzoxazole and various Schiff base moieties

R K Dubey*, U K Dubey & C M Mishra

Received 13 September 2005; revised 26 September 2006

Some new complexes of iron (III) of the type [(m-Cl)2Fe2{h2-(pbox)}4] (1) and [(Cl)2Fe{h2-(pbox)}] (2) [where Hopbox={2-(o-hydroxyphenyl)}-benzoxazole], have been synthesized by the interactions of iron(III) chloride with the corresponding ligand (Hopbox)  in 1:2 and 1:1 molar ratio(s) in hot ethanol as reaction medium. The complex 1 has been further treated with various sodium salts of Schiff bases (sb) [Na(o-smab), Na(p-smab) and Na(sap)], alkoxo-Na(OPri), aryloxo-Na(OAr) and tetraiso­propoxyaluminate [Na{Al(OPri)}4] in 1:1 molar ratio (in THF-benzene medium) to produce derivatives of the type: {(sb)Fe{h2-pbox)}2] (3), (4) and (5), [(m-OPri)2Fe2{h2-(pbox)4}] (6) [(m-OAr)2 Fe2{h2-(pbox)4}] (7) and [(m-OPri)2Al(OPri)2- Fe{h2-(pbox)2}] (8). All these derivatives have been characterised by elemental analysis, spectral (IR, UV-vis and FAB-mass) and magnetic susceptibility measurements. On the basis of these studies, most plausible structures for the iron(III) complexes have been suggested.

IPC Code: Int. Cl.8  C07C251/02; C07F15/02

Indian Journal of Chemistry

Vol. 45A, December. 2006, pp. 2638-2643

 

Synthesis and spectroscopic characterisation of new types of mixed ligand homo- and heterobimetallic derivatives of butyltin(IV)

 

Nandu Bala Sharma & Anirudh Singh*

Received 23 February 2006; revised 18 September 2006

Interaction in equimolar ratio of BuSn(OPri)3 with an appropriate Schiff base (L1H2 or L2H2), where L1 = OC10H6CH=NCH2CH2O and L2 = CH3C(O)CHC(=NCH2CH2O)CH3) yields compounds (1) or (2) respectively, which on reaction with glycols in equimolar ratios afford mixed-ligand derivatives BuSn(L)(OGOH) [where L = L1, G = CHCH3CHCH3 (G1) (3); L = L1, G = C(CH3)2C(CH3)2 (G2) (4) and L = L2, G = G1 (5)]. Equimolar reactions of (3)-(5) with Al(OPri)3 afford heterobimetallic derivatives of the type BuSn(L)(OGOAl(OPri)2) (where L = L1, G = G1 (6); L = L1, G = G2 (7); and L = L2, G = G1 (8)). All these derivatives (1)-(8) have been characterised by elemental analyses, molecular weight measurements and spectroscopic [IR, and NMR (1H, 119Sn, and 27Al)] studies.

IPC code: Int. Cl.8C07C251/02; C07F7/22

 

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2644-2649

 

Synthesis and spectroscopic characterization of mixed ligand complexes of oxovanadium(V)

Rajendra Singh Ghadwal & Anirudh Singh*

Received 23 February 2006; revised 18 September 2006

Equimolar reaction of VO(OPri)3 with N-phenyldiethanolamine affords [VO(L)(m-OPri)]2 (1), which reacts with a variety of mono- and bi-dentate ligands such as MeOH, EtOH, MeOCH2CH2OH, MeNHCH2CH2OH, Me3CCH2OH, Me3COH, EtCMe2OH, and C10H7N=CHC6H4OH (where C10H7 represents napthyl group) yielding the dimeric [VO(L)(m-OMe)]2(2), [VO(L)(m-OEt)]2(3), [VO(L)(m-OCH2CH2OMe)]2(4), [VO(L)(m-OCH2CH2NHMe)]2(5), [VO(L)(m-OCH2CMe3)]2(6), [VO(L)(m-OCMe3)]2(7), [VO(L)-(m-OCMe2Et]2(8), and the monomeric complexes, [VO(L)(OC6H4CHNC10H7)](9), respectively. A detailed study of alcoholysis reactions of VO(L)(OPri) with a number of monofunctional alcohols indicates the following order of reactivity: OMe > OEt » OCH2CH2OMe » OCH2CH2NHMe > OCH2CMe3 > OCMe3 > OCMe2Et. All of these complexes have been characterized by elemental analyses, molecular weight measurements and spectroscopic (IR, 1H and 51V NMR) studies, on the basis of which plausible structures have been suggested for the novel complexes.

Indian Journal of Chemistry

Vol. 45A, December 2006, pp. 2650-2657

 

Densities, viscosities and excess thermodynamic properties of ternary liquid mixtures of nitrobenzene with polar and non-polar solvents at 298.15 K

 

Poonam Rathore & Mukhtar Singh*

Received 12 September 2005; rerevised 12 October 2006

Densities and viscosities of ternary liquid mixtures of nitrobenzene + methyl alcohol + (benzene; + toluene; + carbon tetrachloride; + 1,4-dioxane) have been determined at 298.15 K. From density and viscosity data, values of viscosity deviations and thermodynamic excess properties, viz., excess molar volume and excess Gibbs free energy of activation of viscous flow for the ternary mixtures have been determined and fitted to Cibulka’s equation. The results of the study show that experimental values of these properties are in close agreement with those predicted by Cibulka’s equation.

IPC Code: G01N9/00; G01N11/00

 

Indian Journal of Chemistry

Vol. 45A, December. 2006, pp. 2658-2660

 

Solvent extraction and determination of scandium(III) with Cyanex272 as an extractant

Manjusha Karve* & Bhagyashree Vaidya

Received 1 May 2006; revised 21 September 2006

A novel method for the solvent extraction separation of scandium(III) at pH 5.0 using 5 ´ 10-4 M Cyanex272 has been developed. Scandium(III) has been stripped from the organic phase with 1.0 M HNO3 and determined spectrophotometrically as its complex with Arsenazo(III) at 675 nm. The method developed has been applied for selective separation of scandium(III) from some closely associated elements, viz., La(III), Y(III), Ce(IV), Zr(IV), Dy(III), Nd(III), Pr(III), Yb(III), etc. in their binary mixtures. The method permits mutual separation of scandium(III)-yttrium(III)-lanthanum(III) and scandium(III)-yttrium(III)-cerium(IV) and for recovery of scandium(III) from USGS standard soil sample GXR-2, Japanese stream sediment sample Jsd-3 and ashes from Hutti gold mines in Karnataka. The method presented is simple, rapid and selective for isolation of scandium(III) from complex mixtures. The method developed is reproducible with a relative standard deviation of 0.4%.

IPC code: Int. Cl8 B01D11/00; G01N21/25