Indian Journal of Chemistry

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

 

VOLUME 46A

NUMBER 11

November 2007

 

CONTENTS

 

1733

 

Hypoenergetic molecular graphs

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ivan Gutman* & Slavko Radenković

 

 

 

A molecular graph is said to be hypoenergetic if E<n, where n is the number of vertices. There are only four hypoenergetic graphs with maximal vertex degree not exceeding 3, i.e. graphs representing conjugated π-electron systems. However, there are infinitely many hypoenergetic graphs with maximal vertex degree equal to 4, i.e. molecular graphs of saturated hydrocarbons.

 

 

 

Text Box: [Complex]

 

1737

 

Homogeneous catalysis of manganese(II) in the acid bromate oxidation of malonic acid in the presence of bromocomplexing metal ions: Unusual kinetic behaviour of malonic acid

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cherkupally Sanjeeva Reddy

 

 

 

Manganese(II)-catalysed pure bromate oxidation of malonic acid  in aqueous acetic acid media containing sulphuric acid and Hg(II)/Tl(III) is free from induction period and exhibits 1.5 order in [bromate] and 0.75 order in [Mn(II)]. The proposed mechanism involves oxidation of the formed Mn(II)-malonic acid binary complex to an intermediate by acid bromate which subsequently decomposes to the products. Reaction constants involved in the proposed mechanism are also discussed.

 

 

 

1747

 

Carbon nanotubes supported platinum catalysts for selective hydrogenation of m- and o-chloronitro-benzene

 

 

 

 

 

 

 

Xiaoxiang Han* & Jianrong Li

 

 

 

Hydrogenation of m- and o-chloronitrobenzene (CNB) has been studied over Pt/CNTs and PtM/CNTs catalysts (M= Mn, Fe, Co, Ni and Cu) in ethanol. PtFe/CNTs catalyst exhibits the best catalytic activity and the highest yield of m- and o-chloroaniline (CAN) Different reductants have been found to influence both the catalytic activity and yield of m-CAN. Pt/CNTs catalyst reduced by KBH4 exhibits good catalytic activity and stability on the hydrogenation of m-CNB.

 

1753

 

Synthesis and characterization of [Mn(diik)3](ClO4)2 [diik = N,N˘-carbonyldiimidazole and [Mn(imH)6] (ClO4)2 [imH = imidazole]: A 2D supramolecular sheet structure in [Mn(imH)6](ClO4)2 through
N-H…O and C-H…O hydrogen bonds

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Abhijit Sarkar, Sutonu Pal, Rajarshi Ghosh*, Pradip Kumar Dan & Barindra Kumar Ghosh*

 

 

 

Two mononuclear complexes [Mn(diik)3](ClO4)2 (1) [diik = N,N˘-carbonyldiimidazole] and [Mn(imH)6](ClO4)2 (2) [imH = imidazole] are isolated and characterized using microanalytical, spectroscopic and other physicochemical results.

 

1758

 

2,2-Dialkyl-2H-benzimidazoles, the high energy tautomers of the corresponding 1,2-dialkyl-1H-benzimidazoles. Syntheses and their complexes with Cu(I) and Ag(I)

 

 

 

Goutam K Patra, Israel Goldberg,
Michael G B Drew, Senjuti De, Jnan P Naskar & Dipankar Datta*

 

 

 

Reaction of Cu(1,2-phenylenediamine)2(ClO4)2 with neat RR˘=O (R = methyl and/or ethyl) gives Cu(2,2-dialkyl-2H-benzimidazole)ClO4, demetallation of which by the action of aqueous ammonia yields pure 2,2-dialkyl-2H-benzimidazoles. Although 2H-benzimidazoles are very unstable in the free state, they are quite stable in their Cu(I) and Ag(I) complexes.

 

 

1763

 

Viscosities of binary liquid mixtures of some n-alkoxypropanols with n-alkanols at 298.15 K

 

 

 

 

 

 

 

 

Amalendu Pal* & Rekha Gaba

 

 

 

The viscosities (h) in binary liquid mixtures of (n-alkoxypropanols + methanol, ethanol, or 1-propanol) have been measured as a function of composition using an Ubbelohde viscometer. The h values for each of the mixture studied are positive over the whole mole fraction range. The excess free energies of activation (DG*E) for viscous flow have been calculated from the experimental data. The results for h, Dh, and DG*E are discussed in terms of interactions between the components of the mixtures. Equations such as Heric’s, Auslaender’s, and McAllister’s four-body interaction model have been used to correlate the kinematic viscosities.

 

1772

 

A novel [2] rotaxane hydroxamic acid for the liquid-liquid extraction and determination of vanadium (V)

 

 

 

 

 

 

 

 

 

Y K Agrawal* & C R Sharma

 

 

 

A new reagent, [2] rotaxane hydroxamic acid, is reported for extraction and trace determination of vanadium (V) in nutritional and biological substrates.

 

Notes

 

1778

 

Chromium(VI) catalyzed oxidation of indole in aqueous acetic acid

 

 

 

 

 

 

 

 

 

 

 

 

Subbiah Meenakshisundaram* & N Sarathi

 

 

 

The catalytic activity of picolinic acid, 1,10-phenanthroline, oxalic acid, 2,2˘-bipyridyl and ethylenediamine tetracetic acid have been investigated in the chromium(VI) oxidation of indole in aqueous acetic acid medium. The catalysts increase the electrophilic activity of the oxidant and the Cr(VI)-Cat complex is believed to be the reactive electrophile. The proposed reaction pathway involves the electrophilic attack of the Cr(VI)-Cat complex at the ethylenic bond of the indole ring to give an indoleninic intermediate. The relative catalytic activity for indole oxidation in the presence of different catalysts reveals that picolinic acid is the best catalyst under the experimental conditions while activity of EDTA is minimum.

 

 

1782

 

Synthesis and spectral characterization of zinc(II) complexes of 12-membered oxa-azamacrocycles

 

 

 

 

R N Prasad* & Amita Jain

 

 

 

Zn(II) complexes of the type ZnLCl2 (where L = 12-membered N2O2 macrocycle) have been synthesized by the 1+1 cyclocondensation of 1,8-diamino-3,6-dioxaoctane with a-diketones such as 2,3-butanedione, 2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione, 1-phenylpropane-1,2-dione and benzil in the presence of Zn(II).

 

 

1787

 

Synthesis, crystal structure and biological activity of a new complex bis(1,1-diethyl-3-(3-fluorobenzoyl)-thiourea)nickel(II)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

You-Ming Zhang, Hai-Xia Pang, Cheng Cao & Tai-Bao Wei*

 

 

 

A new complex bis(1,1-diethyl-3-(3-fluorobenzoyl)-thiourea) nickel (II) (NiL2) has been synthesized and characterized.

 

 

 

1792

 

Kinetics and mechanism of oxidation of chalcones by trichloroisocyanuric acid [TCICA] in HOAc-HClO4 medium

 

 

 

 

 

 

 

 

J Anil Kumar & S Sondu*

 

 

 

The kinetics and mechanism of oxidation of chalcone and some substituted chalcones by trichloroisocyanuric acid (TCICA) has been investigated at 313 K in HOAc-HClO4 medium. The reaction has been found to be first order each in [TCICA] and [Chalcone] and fractional order in [H+]. The reactive species of oxidant have been established as HOCl and H2OCl+. The rate increases with electron releasing groups in the benzaldehyde moety and vice versa with a Hammett’s r value of –0.45. A suitable mechanism involving the chalcone molecule and the reactive species of TCICA in the rate determining step has also been proposed.

 

 

1796

 

Restriction of pesticidal movement in contaminated soil and water

 

 

 

 

 

 

 

Deepesh Bhardwaj, Pankaj Sharma &
Radha Tomar*

 

 

 

Studies on restriction of pesticidal movement in contaminated soil and water are reported here. Sorption isotherms could be well described by the Freundlich equation form for all the three materials. Sorption of malathion on SAS-I and SAS-II has been found to be higher than that on SAS-III whereas desorption is less in case of SAS-III. Thermodynamic parameters for sorption have also been calculated to predict the mechanism of sorption. It has been found that varying the sorptive properties of synthetic aluminosilicates results in immobilization of pesticides in a contaminated soil and protection of soil and water by using the aluminosilicates as pesticide carrier in slow release formulations.

 

 

1801

 

Determination of Eu(III) based on fluorescence and cofluorescence enhancement of Eu(III)-Tb(III)-tetracycline-citrate system

 

 

 

 

 

 

 

 

 

 

Xiaoli Wang, Huichun Zhao* & Linpei Jin

 

 

 

A new sensitized cofluorescence system has been developed for the determination of Eu(III) based on its complex formation with tetracycline (TC) in the presence of citrate and Tb(III). Eu(III) forms complex with tetracycline in alkaline condition which emits intrinsic fluorescence of Eu(III) when excited. The fluorescence intensity of Eu(III)-TC is enhanced about 5 times when citrate and Tb(III) are introduced. Under optimum conditions, the relative fluorescence intensity is linear in over the range 6.0×10-9 to 4.0×10-6 M of Eu(III).  The method has been used for the determination of Eu in two rare earth samples with relative error 4.5% and -1.8%, and RSD 2.6% and 2.1%, respectively.

 

 

Authors for correspondence are indicated by (*)


 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1733-1736

 

Hypoenergetic molecular graphs

Ivan Gutman* & Slavko Radenković

Received 30 August 2007; accepted 10 October 2007

The energy E of a (molecular) graph is equal to the sum of the absolute values of its eigenvalues. A molecular graph is said to be hypoenergetic if E<n, where n is the number of vertices. There are only four hypoenergetic graphs with maximal vertex degree not exceeding 3, i.e. graphs representing conjugated π-electron systems. However, there are infinitely many hypoenergetic graphs with maximal vertex degree equal to 4, i.e. molecular graphs of saturated hydrocarbons.

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1737-1746

 

Homogeneous catalysis of manganese(II) in the acid bromate oxidation of malonic acid in the presence of bromocomplexing metal ions: Unusual kinetic behaviour of malonic acid

Cherkupally Sanjeeva Reddy

Received 15 December 2006; rerevised 11 September 2007

Manganese(II)-catalysed pure bromate (unmixed with Br2) oxidation of malonic acid (MA) in aqueous acetic acid media containing sulphuric acid and Hg(II)/Tl(III), bromocomplexing metal ion, is free from induction period and exhibits 1.5 order in [bromate] and 0.75 order in [Mn(II)]. The reaction rate increases with increasing [H2SO4] and the rate constant follows the ho function. The kinetic behaviour of MA is unusual, being 0.15 order in the lower [MA] range and tending to -0.32 order at higher [MA]. Redox potential for the Mn(II)/Mn(III)-malonic acid couple is determined as 0.89 V (vs SCE) and 1.15 V (vs NHE). These findings are accounted quantitatively and the catalytic effect of Mn(II) ion is displayed by its complex forming ability. The proposed mechanism involves oxidation of the formed Mn(II)-malonic acid binary complex to an intermediate by acid bromate which subsequently decomposes to the products. Reaction constants involved in the proposed mechanism have been evaluated and discussed.

IPC Code: Int. Cl.8 CO7B33/00

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1747-1752

 

Carbon nanotubes supported platinum catalysts for selective hydrogenation of m- and o-chloronitrobenzene

Xiaoxiang Han* & Jianrong Li

Received 1 June 2007; revised 16 October 2007

Hydrogenation of m- and o-chloronitrobenzene (CNB) has been studied over Pt/CNTs and PtM/CNTs catalysts (M= Mn, Fe, Co, Ni and Cu) in ethanol at 343 K and normal pressure. The effect of substrate concentration and reaction temperature has also been investigated. The introduction of transition metals to Pt/CNTs catalyst influences its catalytic properties significantly. Both the catalytic activities and yields of m- and o-chloroaniline (CAN) are improved. PtFe/CNTs catalyst exhibits the best catalytic activity and the highest yield of CAN (98.1 mol% for m-CAN and 97.5 mol% for o-CAN). Different reductants have been found to influence both the catalytic activity and yield of m-CAN. Pt/CNTs catalyst reduced by KBH4 exhibits good catalytic activity and stability on the hydrogenation of m-CNB.

IPC Code: Int. Cl.8 B01J21/18C

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1753-1757

 

Synthesis and characterization of [Mn(diik)3](ClO4)2 [diik = N,N˘-carbonyldiimidazole and [Mn(imH)6](ClO4)2 [imH = imidazole]: A 2D supramolecular sheet structure in [Mn(imH)6](ClO4)2 through N-H…O and C-H…O hydrogen bonds

Abhijit Sarkar, Sutonu Pal, Rajarshi Ghosh,*, Pradip Kumar Dan & Barindra Kumar Ghosh,*

Received 21 May 2007; revised 26 September 2007

Two mononuclear complexes [Mn(diik)3](ClO4)2 (1) [diik = N,N˘-carbonyldiimidazole] and [Mn(imH)6](ClO4)2 (2) [imH = imidazole] are isolated and characterized using microanalytical, spectroscopic and other physicochemical results.X-ray structural study of 2 reveals Mn(II) center to assume centrosymmetric octahedral geometry with an MnN6 chromophore ligated by six N atoms of the six imH unit. The mononuclear units in 2 are engaged in N-H…O and C-H…O hydrogen bondings leading to a 2D sheet structure in ac plane. Complexes 1 and 2 display intraligand 1(p-p*) fluorescence at room temperature.

IPC Code: Int. Cl.8 C07F13/00

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1758-1762

 

2,2-Dialkyl-2H-benzimidazoles, the high energy tautomers of the corresponding 1,2-dialkyl-1H-benzimidazoles. Syntheses and their complexes with Cu(I) and Ag(I)

Goutam K Patra, Israel Goldberg, Michael G B Drew, Senjuti De, Jnan P Naskar & Dipankar Datta,*

Received: 28 June 2007; revised 13 September 2007

Reaction of Cu(1,2-phenylenediamine)2(ClO4)2 with neat RR˘=O (R = methyl and/or ethyl) gives Cu(2,2-dialkyl-2H-benzimidazole)ClO4, demetallation of which by the action of aqueous ammonia yields pure 2,2-dialkyl-2H-benzimidazoles. These are characterised by NMR. In the X-ray crystal structure, Ag(2,2-methyl-2H-benzimi-dazole)NO3 is found to be a spiral 1D coordination polymer where the 2H-benzimidazole acts as an N,N bridge between two Ag(I) centers. Although 2H-benzimidazoles are very unstable in the free state, they are quite stable in their Cu(I) and Ag(I) complexes. The 1,2-tautomerisation in imidazole and benzimidazole have been studied by means of transition state calculations at B3LYP/6-311+G(2d,p)* level.

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1763-1771

 

Viscosities of binary liquid mixtures of some n-alkoxypropanolswith n-alkanols at 298.15 K

Amalendu Pal* & Rekha Gaba

Received 1 August 2006; rerevised 22 August 2007

The viscosities (h) in binary liquid mixtures of (n-alkoxypropanols + methanol, ethanol, or 1-propanol) have been measured as a function of composition using an Ubbelohde viscometer at 298.15 K and atmospheric pressure over the full range of composition. The n-alkoxypropanols are propylene glycol monomethyl ether (1-methoxy-2-propanol), CH3OCH2CH2CH2OH, propylene glycol monoethyl ether (1-ethoxy-2-propanol), C2H5OCH2CH2CH2OH, propylene glycol monopropyl ether (1-propoxy-2-propanol), C3H7OCH2CH2CH2OH, propylene glycol monobutyl ether (1-butoxy-2-propanol), C4H9OCH2CH2CH2OH propylene glycol tert-butyl ether (1-tert-butoxy-2-propanol), CH3CHOHCH3OC(C4H9)3. The h values for each of the mixture studied are positive over the whole mole fraction range. For all the cases, except propylene glycol tert-butyl ether, h increases in a positive direction with increase in chain length of n-alkoxypropanols. The values of Dh, which refers to the deviation of the experimental values of the dynamic viscosities of the mixtures from the mole fraction mixture law values, are found to be positive for all the mixtures. Further, the excess free energies of activation (DG*E) for viscous flow have been calculated from the experimental data. The results for h, Dh, and DG*E are discussed in terms of interactions between the components of the mixtures. Equations such as Heric’s, Auslaender’s, and McAllister’s four-body interaction model have been used to correlate the kinematic viscosities.

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1772-1777

 

A novel [2] rotaxane hydroxamic acid for the liquid-liquid extraction and determination of vanadium(V)

Y K Agrawal* & C R Sharma

Received 19 January 2007; revised 27 September 2007

A new reagent, [2] rotaxane hydroxamic acid, is reported for extraction and trace determination of vanadium(V) in nutritional and biological substrates. The extraction mechanism of vanadium from 6 M HCl media is investigated. Optimum conditions like solvent, influence of reagent and diverse ions etc on the extraction of vanadium have been examined. The overall stability constant (logβ2Ke) and extraction constant (Kex) in chloroform are 2.50 ± 0.02 and 4.0 ± 0.02 ´ 10-8 respectively. The system obeys Beer’s law in the range of 0.815-3.26 mg mL-1 of vanadium(V). The molar absorptivity is 6.66 ´ 103 L mol-1 cm-1 at 525 nm. The vanadium(V) complex chloroform extract has been directly inserted into plasma for ICP-AES measurements, which increases the sensitivity by 50 folds. The method is applied for determination of vanadium(V) in standard samples, sea water and environment samples.

IPC Code: Int. Cl.8  B01D11/00

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1778-1781

 

Chromium(VI) catalyzed oxidation of indole in aqueous acetic acid

Subbiah Meenakshisundaram* & N Sarathi

Received 21 August 2006; revised 1 October 2007

The catalytic activity of picolinic acid, 1,10-phenanthroline, oxalic acid, 2,2˘-bipyridyl and ethylenediamine tetracetic acid have been investigated in the chromium(VI) oxidation of indole in aqueous acetic acid medium. The catalysts increase the electrophilic activity of the oxidant and the Cr(VI)-Cat complex is believed to be the reactive electrophile. The proposed reaction pathway involves the electrophilic attack of the Cr(VI)-Cat complex at the ethylenic bond of the indole ring to give an indoleninic intermediate. The reaction is routed through via a termolecular complex, Cr(VI)-Cat-IND, the decomposition of which in slow rate determining step is envisaged to explain the reactivity. In presence of the catalyst, indole is oxidized by chromium(VI) to give oxindole as the major product, under most conditions. The conversion is favoured in a medium of low dielectric constant. The failure to observe inhibition in the presence of acrylonitrile suggests the non-radical mechanistic pathway. The ratio, k(D2O)/k(H2O) » 1, does not seem to indicate any significant solvent isotope effect. Cobalt(III) enhances the reactivity while pyridine and chromium(III) depress the reactivity. The relative catalytic activity for indole oxidation in the presence of different catalysts reveals that picolinic acid is the best catalyst under the experimental conditions while activity of EDTA is minimum. A detailed interpretation of the redox mechanism based on the available kinetic data has been proposed.

IPC Code: Int. Cl.8 CO7B33/00

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1782-1786

 

Synthesis and spectral characterization of zinc(II) complexes of 12-membered oxa-azamacrocycles

R N Prasad* & Amita Jain

Received 17 October 2006; revised 22 October 2007

Zn(II) complexes of the type ZnLCl2 (where L = 12-membered N2O2 macrocycle) have been synthesized by the 1+1 cyclocondensation of 1,8-diamino-3,6-dioxaoctane with a-diketones such as 2,3-butanedione, 2,3-pentanedione, 2,3-hexanedione, 3,4-hexanedione, 1-phenylpropane-1,2-dione and benzil in the presence of Zn(II). The complexes have been characterized by elemental analyses, molar conductances, IR, 1H NMR and FAB mass spectral studies.

IPC Code: Int.Cl.8C07F3/06

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1787-1791

 

Synthesis, crystal structure and biological activity of a new complex,+ bis(1,1-diethyl-3-(3-fluorobenzoyl)-thiourea)nickel(II)

You-Ming Zhang, Hai-Xia Pang, Cheng Cao & Tai-Bao Wei*

Received 7 May 2007; revised 8 October 2007

A new complex bis(1,1-diethyl-3-(3-fluorobenzoyl)-thiourea) nickel (II) (NiL2) has been synthesized and characterized by IR, 1H NMR, 13C NMR spectra and elemental analysis. Structure of the complex has been determined by single crystal X-ray diffraction (CCDC 633339). The two ligand molecules adopt a cis-conformation bonded to the Ni(II) ion and the central nickel ion has four-coordination square-planar geometry contributed by two S and two carbonyl O atoms. Both the complex NiL2 and its free ligand HL (1,1-diethyl-3-(3-fluorobenzoyl)-thiourea) exhibit powerful plant growth regulating activity towards the root of rape and compared with the free ligand HL. The complex NiL2 displays more promoting activity in lower concentrations.

IPC Code: Int. Cl.8 CO7F15/04

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1792-1795

 

Kinetics and mechanism of oxidation of chalcones by trichloroisocyanuric acid [TCICA] in HOAc-HClO4 medium

J Anil Kumar & S Sondu*

Received 31 August 2007; revised 19 October 2007

The kinetics and mechanism of oxidation of chalcone and some substituted chalcones by trichloroisocyanuric acid (TCICA) has been investigated at 313 K in HOAc-HClO4 medium. The reaction has been found to be first order each in [TCICA] and [Chalcone] and fractional order in [H+]. There is no kinetic or spectral evidence for the formation of complex between TCICA and Chalcone. The rate increases with increase in percentage of acetic acid and [Cl-]. The products of oxidation have been identified as phenyl acetaldehyde and benzoic acid. The reactive species of oxidant have been established as HOCl and H2OCl+. The rate increases with electron releasing groups in the benzaldehyde moety and vice versa with a Hammett’s r value of –0.45. A suitable mechanism involving the chalcone molecule and the reactive species of TCICA in the rate determining step has also been proposed.

IPC Code: Int. Cl.8 C07B33/00

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1796-1800

 

Restriction of pesticidal movement in contaminated soil and water

Deepesh Bhardwaj, Pankaj Sharma & Radha Tomar*

Received 24 April 2007; revised 20 September 2007

Studies on restriction of pesticidal movement in contaminated soil and water are reported here. Sorption isotherms could be well described by the Freundlich equation form for all the three materials. Sorption of malathion on SAS-I and SAS-II has been found to be higher than that on SAS-III whereas desorption is less in case of SAS-III. Thermodynamic parameters for sorption have also been calculated to predict the mechanism of sorption. The thermodynamic studies suggest exothermic and physicochemical nature of sorption process. The FTIR analysis and thermodynamic studies exhibit the possibility of hydrogen bonding between the substrate and the pesticide molecule. It has been found that varying the sorptive properties of synthetic aluminosilicates results in immobilization of pesticides in a contaminated soil and protection of soil and water by using the aluminosilicates as pesticide carrier in slow release formulations.

IPC Code: Inc. Cl.8C01B33/26

 

Indian Journal of Chemistry

Vol. 46A, November 2007, pp. 1801-1804

 

Determination of Eu(III) based on fluorescence and cofluorescence enhancement of Eu(III)-Tb(III)-tetracycline-citrate system

Xiaoli Wang, Huichun Zhao* & Linpei Jin

Received 6 February 2007; revised 24 September 2007

A new sensitized cofluorescence system has been developed for the determination of Eu(III) based on its complex formation with tetracycline (TC) in the presence of citrate and Tb(III). Eu(III) forms complex with tetracycline in alkaline condition which emits intrinsic fluorescence of Eu(III) when excited. The fluorescence intensity of Eu(III)-TC is enhanced about 5 times when citrate and Tb(III) are introduced. The factors that influence the fluorescence intensity of the system have been studied in detail. Under optimum conditions, the relative fluorescence intensity is linear in over the range 6.0×10-9 to 4.0×10-6 M of Eu(III).  The detection limit has been found to be 1.4×10-9 M of Eu(III). The method has been used for the determination of Eu in two rare earth samples with relative error 4.5% and -1.8%, and RSD 2.6% and 2.1%, respectively.

IPC Code: Int. Cl.8 G01N21/64