Indian Journal of Chemistry

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

Total visitors: 1,180      since 23-08-06

 

VOLUME 45A

NUMBER 8

AUGUST 2006

CONTENTS

Papers

 

1789

 

Conceptual density functional study on the formation of supermolecules by the chemical interaction of some ligands as electron pair donors and boron trifluoride as electron pair acceptor

 

 

 

 

Dulal C Ghosh* & Soma Bhattacharyya

 

 

 

 

BF3, a Lewis acid and a number of Lewis bases, viz., HCN, HNC, H3C CN and H3C NC, have been chemically interacted through charge transfer to form supermolecules like F3BNCH, F3BCNH, F3BNCCH3 and
F3BCNCH3. The computed values of hardness, chemical potential and electronegativity of the donors, acceptor and the supermolecules reveal that the formation of acid-base supermolecules are in accordance with the electronegativity equalization principle and the maximum hardness principle.

 

 

 

1796

 

Excited state intramolecular proton transfer in salicylidine 3,4,7-methyl amine: Spectroscopic and theoretical investigations

 

 

 

 

 

 

 

 

 

M Mukhopadhyay, D Banerjee, A Koll,
A Filarowski, D Guha & S Mukherjee*

 

 

 

 

A new ortho-hydroxy Schiff base, salicylidine-3,4,7-methylamine, has been synthesized and the excited state intramolecular proton transfer (ESIPT) process has been investigated in some nonpolar and weakly polar solvents at room temperature and at 77 K. The ESIPT is evidenced by a large Stokes shifted emission (~10,700 cm-1) both at room temperature and at 77 K. The keto tautomer is found to be the predominant species in the excited state at 77 K. Theoretically determined energetics of the ground and excited state proton transfer in SMA at AM1 level of approximation predict that the ground singlet proton transfer path would have considerable barrier, while the barrier height should be much lower, both on the corresponding excited singlet and triplet surfaces.

 

 

1804

 

Are there variations in hydrogen bonding abilities of Watson Crick region and other donor-acceptor sites of nucleobases? An ab initio method of studying proton and metal ion affinities of nucleobases

 

 

 

 

 

 

 

 

 

 

 

 

D Talukdar, R Parajuli, R Kalita & C Medhi*

 

 

 

 

Proton affinities of donor-acceptor sites located in Watson Crick and those in the other regions of nucleobases are significantly different. The interaction of highly basic site of a nucleobase with compatible atomic sites of another nucleobase may be the dominant factor for stabilization of Watson Crick hydrogen bonds. The metal ions interact with multiple atomic sites in most cases, whereas protonation takes place at a particular atomic site only.

 

 

 

 

1813

 

Synthesis, crystal structure and thermal analysis of three supramolecular architectures containing Mn(II)/Fe(II) built by 4, 4′-bipyridyl N, N′-dioxide and pseudohalides

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Subal Chandra Manna, Ennio Zangrando,
Ken-ichi Okamoto & Nirmalendu Ray Chaudhuri*

 

 

 

 

Three new 3D supramolecular architectures of Mn(II) and Fe(II), [Fe(dca)2(dpyo)2(H2O)2], [Mn(SCN)2(dpyo)-(H2O)(MeOH)] and [Fe(SCN)2(dpyo)(H2O)2](H2O),
[dca = dicyanamide ion; dpyo = 4,4′-bipyridine N,N′-dioxide] have been synthesized and characterized.

 

 

 

 

1820

 

Preparation, characterization and crystal structure of phenylene-1, 3-diammonium sulfate

 

 

 

 

 

 

 

 

 

 

 

 

 

Inder Pal Singh Kapoor, Pratibha Srivastava, Gurdip Singh* & Roland Frhlich

 

 

 

 

Phenylene-1,3-diammonium sulfate crystallizes in
the triclinic space group P-1 with unit cell dimensions,
a =9.017 (1) , b =11.682 (1) , c =16.678 (1) ,
α =100.56 (1), β =103.25 (1), γ =111.44 (1), Z = 6,
Dx = 1.508 g cm-3. The structure forms very complicated hydrogen bonded net.

 

 

 

 

 

 

1825

 

Catalytic cleavage of p-nitrophenyl diphenyl phosphinate by hydroxamate ions

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Sunita Bal, Sancheeta Kolay, Ashish Shrivastava,
D K Dubey & Kallol K Ghosh*

 

 

 

 

 

 

Notes

 

 

1831

 

Novel method of fabrication of doped polyaniline nanostructures

 

 

 

 

 

 

 

 

 

 

 

 

 

A Gupta, S Goel , K P Singh , R Mehrotra* &
H C Kandpal

 

 

 

 

One-dimensional micro/nanostructures of doped polyaniline have been grown on ground glass surface using an in situ oxidative polymerization reaction without the support of host templates.

 

 

 

 

 

1836

 

Synthesis and characterization of nickel phosphate based porous frameworks under microwave-hydrothermal conditions

 

 

 

 

 

 

 

 

 

T Chiranjeevi, Bharat L Newalkar &
N V Choudary*

 

 

 

 

 

 

 

 

1840

 

Synthesis and crystal structure of a nido
11-vertex diplatinaundecaborane cluster
[(μ-PPh2)(PPh3)2Pt2B9H7-9, 11-(OiPr)2]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Li-Bin Wu, Jian-Min Dou*, Qing-Liang Guo,Da-Cheng Li & Da-Qi Wang

 

 

 

 

The nido 11-vertex diplatinaundecaborane,
[(
m-PPh2)(PPh3)2Pt2B9H7-9,11-(OiPr)2], has been obtained by the reaction of [PtCl2(PPh3)2] with B10H102- in the presence of iPrOH under solvothermal conditions.

 

 

 

 

 

 

1844

 

LSER and LFER in the reaction of benzimidazole with benzyl bromide

 

 

 

 

 

 

 

 

 

S Ranga Reddy & P Manikyamba*

 

 

 

 

The second order rate constants of the nucleophilic substitution reaction of benzyl bromide with benzimidazole have been obtained conductometrically in 11 different solvents in the temperature range 303 318 K. Substituent effect on rate of the reaction suggests that both electron donating group (p-CH3) and electron withdrawing groups (p-NO2, p-Br) enhance the rate of the reaction as compared to the unsubstituted compound. The substituted (p-NO2 and p-Br) and the unsubstituted compound form a linear free energy relationship.

 

 

 

1848

 

Voltammetric response of 2,4-D-molecularly imprinted film modified glassy carbon electrodes

 

 

 

 

 

 

 

Zhihua Wang, Jingwan Kang*, Xiaoyu Liu & Yongjun Ma

 

 

 

 

A novel voltammetric sensor has been developed based on the molecular recognition of the template by imprinted technology. The sensitive layer has been prepared by electropolymerization of ortho-phenylenediamine and resorcinol on glassy carbon electrode in the presence of the template molecule. After the template extraction from the resultant solution, re-binding of 2,4-D has been done from 0.1 mol/L H2SO4 containing the analyte. The sensor exhibits good sensitivity and reproducibility for 2,4-D due to the interaction between molecularly imprinted binding sites and template.

 

 

 

1852

 

Solid phase extraction and spectrophotometric determination of platinum(IV) with N-(3,5-dihydroxyphenyl)-N-(4-aminobenzenesulfonate) thiourea

 

 

 

 

 

 

 

Zhigang Li, Xuemei Li, Liya Zhu, Qiufen Hu,
Jing Chen & Guangyu Yang*

 

 

 

 

A highly sensitive, selective and rapid method
for the determination of platinum(IV) based
on its reaction with N-(3,5-dihydroxyphenyl)-N′ -
(4-aminobenzenesulfonate) - thiourea and the solid phase extraction of the Pt(IV) complex with a polymer-based C18 cartridge has been developed. Solid phase extraction with polymer-based C18 cartridge enriches the complex with an enrichment factor of 200. The molar absorptivity of the complex is 1.01105 L mol-1 cm-1 at
760 nm. Beers law is obeyed in the range of 0.01~3.0 mg mL-1 with the detection limit reaching 0.02 mg/L in the original samples.

 

 

 

1856

 

Synthesis and characterization of a Hg(II) selective
n-butyl acetate cerium(IV) phosphate as a new intercalated fibrous ion exchanger: Effect of surfactants on the adsorption behaviour

 

 

 

 

K G Varshney*, M Z A Rafiquee, Amita Somya & Milan Drabik

 

 

 

 

n-Butyl acetate Ce(IV) phosphate, a new Hg(II) selective intercalated fibrous ion exchanger, has been synthesized. Studies on the effect of surfactants on the adsorption behaviour of this material show that for heavy metals ion, adsorption increases with concentration of anionic surfactants up to the CMC value and then decreases. However, for cationic surfactants, the reverse is true. For nonionic surfactants, adsorption remains constant up to the CMC value and then increases.

 

 

 

Authors for correspondence are indicated by (*)

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1789-1795

 

Conceptual density functional study on the formation of supermolecules by the chemical interaction of some ligands as electron pair donors and boron trifluoride as electron pair acceptor

 

Dulal C Ghosh* & Soma Bhattacharyya

Received 21 November 2005; revised 9 May 2006

A number of Lewis bases, viz., HCN, HNC, H3CCN and H3CNC are allowed to chemically interact with BF3, a Lewis acid, through the process of charge transfer and bond formation leading to the formation of F3BNCH, F3BCNH, F3BNCCH3, F3BCNCH3 supermolecules. The ligands chosen are structural isomers with different donating atomic sites of varying degrees of softness. The density functional descriptors like hardness and chemical potential or electronegativity are invoked to study the rationality of formation of such charge transfer complexes. The fundamental theoretical generalizations relied upon in the study are the maximum hardness principle and the electronegativity or chemical potential equalization principle. The present work also attempts to address the stability of the above supermolecules in terms of the recently suggested semiempirical algorithms involving the above stated density functional descriptors. The computed chemical potential induced charge transfer and hardness induced reaction energy of all such supermolecules are perfectly in accordance with their theoretical predictions. The computed values of the hardness, chemical potential and electronegativity of the donors, the acceptor and the supermolecules reveal that the formation of acid-base supermolecules are in accordance with the electronegativity equalization principle and the maximum hardness principle. The variation of heats of formation of the supermolecules with the change of structure of ligands can be correlated in terms of conceptual density functional descriptors like chemical potential and global hardness. The present work is presented as one more validity test of maximum hardness principle, MHP and chemical potential equalization principle of the density functional theory.

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1796-1803

 

Excited state intramolecular proton transfer in salicylidine -3,4,7-methyl amine: Spectroscopic and theoretical investigations

M Mukhopadhyay, D Banerjee, A Koll, A Filarowski, D Guha & S Mukherjee*

Received 1 February 2006; revised 30 May 2006

A new ortho-hydroxy Schiff base, salicylidine-3,4,7-methy lamine (SMA) has been synthesized. Investigation has been done on the excited state intramolecular proton transfer (ESIPT) process, employing absorption, emission and nanosecond spectroscopy in some non-polar and weakly polar solvents at room temperature and at 77K. The ESIPT is evidenced by a large Stokes shifted emission (~10,700 cm-1) both at room temperature and at 77K. The keto tautomer is found to be the predominant species in the excited state at 77K. From nanosecond measurements and quantum yields of fluorescence, we have estimated the decay rates of proton transfer reaction. Theoretically determined energetics of the ground and excited state proton transfer in SMA at AM1 level of approximation, predict that the ground singlet proton transfer path would have considerable barrier, while the barrier height should be much lower both on the corresponding excited singlet and triplet surfaces.

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1804-1812

 

Are there variations in hydrogen bonding abilities of Watson Crick region and other donor-acceptor sites of nucleobases? An ab initio method of studying proton and metal ion affinities of nucleobases

D Talukdar, R Parajuli, R Kalita & C Medhi*

Received 20 August 2004; rerevised 9 May 2006

The ability to form intermolecular hydrogen bonds in DNA depends on the donor-acceptor atomic sites present in nucleobases where the formation of a stable Watson Crick type hydrogen bonds (WC) other than non Watson Crick hydrogen bonds (NWC) are generally found. The occurrence of strong hydrogen bond in DNA sequences may be viewed with respect to the donor-acceptor abilities of the atomic sites in nucleobases. The proton and metal ion affinities at different atomic sites of nucleobases have been analyzed for better understanding of the hydrogen bonds in Watson Crick base pairs. There are several significant variations of ion affinities between the Watson Crick sites and other sites of nucleobases; herein proton affinities are high at certain atomic sites within Watson Crick region as well as in other sites. In most metal ion-nucleobase complexes, the metal ion interacts with multiple atomic sites. The proton and metal ion affinities of various sites located in these two regions are found to be different, and the proton can interact preferably at a particular site of nucleobase within the Watson Crick region. These particular sites may control the formation of Watson Crick hydrogen bonds in the sequences. The proton affinities are higher than metal ion affinities. Also, proton interacts with a particular atomic site of nucleobase. Here the proton and metal ion affinities of cytosine (O9) and adenine (N9) in Watson Crick region are significantly higher as compared to those of other sites of these nucleobases. On the other hand, N6 of guanine (NWC) and O1 of thymine (WC) are the most basic sites of these nucleobases. These basic sites may be important in the Watson Crick type base pairing of two prime nucleobases.

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1813-1819

 

Synthesis, crystal structure and thermal analysis of three supramolecular architectures containing Mn(II)/Fe(II) built by 4,4′-bipyridyl N,N′-dioxide
and pseudohalides

Subal Chandra Manna, Ennio Zangrando*, Ken-ichi Okamoto & Nirmalendu Ray Chaudhuri*

Received 1 February 2006; revised 5 May 2006

Three new 3D supramolecular architectures of Mn(II) and Fe(II), [Fe(dca)2(dpyo)2(H2O)2] (1), [Mn(SCN)2(dpyo)-(H2O)(MeOH)] (2) and [Fe(SCN)2(dpyo)(H2O)2](H2O) (3), [dca = dicyanamide ion; dpyo = 4,4′-bipyridine N,N′-dioxide] have been synthesized and characterized by single crystal X-ray diffraction study and thermal analysis. The structure of 1 reveals centrosymmetric mononuclear complex of N2O4 octahedral coordination sphere comprising trans located nitrogens from two nitrile dca, two oxygens from water molecules and two oxygens from dpyo. The mononuclear fragments through H-bonding as well as π-π interactions result in a 3D supramolecular network. The X-ray diffraction analyses of 2 and 3 reveal that they are isomorphous, taking into account that in the former the methanol ligand is replaced by two water molecules. Both the structures have 1D chains which undergo intermolecular H-bonding interaction resulting in 3D supramolecular networks. Complex 1 is thermally more stable than the other two whereas only the deaquated species of 2 is thermally isolable in solid state.

IPC Code: Int. Cl.8 C07F13/00; C07F15/00

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1820-1824

Preparation, characterization and crystal structure of
phenylene-1, 3-diammonium sulfate

Inder Pal Singh Kapoor, Pratibha Srivastava, Gurdip Singh* & Roland Frhlich

Received 26 December 2005; revised 2 June 2006

The preparation, characterization and crystal structure of phenylene-1,3-diammonium sulfate are reported here. The compound crystallizes in the triclinic space group P-1 with unit cell dimensions a =9.017 (1) , b =11.682 (1) , c =16.678 (1) , α =100.56 (1), β =103.25 (1), γ =111.44 (1), Z = 6, Dx = 1.508 g cm-3. The structure forms very complicated hydrogen bonded net. This sulfate salt gives 2,4-diaminobenzenesulfonic acid on thermolysis, which is used in organic syntheses, dyestuffs and sulfa drugs.

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1825-1830

 

Catalytic cleavage of p-nitrophenyl diphenyl phosphinate by hydroxamate ions

Sunita Bala, Sancheeta Kolay, Ashish Shrivastava, D K Dubey & Kallol K Ghosh*

Received 7 March 2006; revised 5 June 2006

The reaction of p-nitrophenyl diphenyl phosphinate with two N-substituted hydroxamic acids
(N-phenylbenzohydroxamic acid and N-methyl 2-chlorobenzohydroxamic acid) in three different cationic surfactants (cetyltrimethylammonium bromide, cetyltriphenylphosphonium bromide and cetyldimethylethanolammonium bromide) at pH 9.1 (27C) have been studied. The pseudo-first order rate constant increases with surfactant concentration. The pseudo-phase model has been applied to rate data to explain the behavior of binding of the substrate and nucleophiles.

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1831-1835

 
Novel method of fabrication of doped polyaniline nanostructures

A Gupta, S Goel, K P Singh , R Mehrotra*& H C Kandpal

Received 14 February 2006; revised 30 May 2006

Micro and nanostructures of doped polyaniline are grown directly on a ground glass surface. An in situ vapor phase chemical oxidative polymerization, directed by the oxidant which has been pre - deposited on the ground glass surface, is used to obtain the micro/nano structures. The morphology of these structures is studied using optical microscopy and field emission scanning electron microscopy. Formation of different types of one-dimensional nanostructures like tubules, fibers, wires and even ribbon-like structures is indicated. The structures obtained have a wide range of size distribution and also different geometries. Infrared spectroscopic characterization of the obtained polyaniline nano/microstructures also indicates the presence of well-ordered doped polyaniline chains. The present work reports a novel, convenient and economical technique for obtaining polyaniline nanostructures and has high technological importance.

IPC Code: Int. Cl.8 B82B3/00; C08G73/02

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1836-1839

Synthesis and characterization of nickel phosphate based porous frameworks under microwave-hydrothermal conditions

T Chiranjeevi, Bharat L Newalkar & N V Choudary*

Received 30 November 2005; revised 22 May 2006

Crystallization of microporous nickel phosphate framework has been investigated under microwave-hydrothermal conditions. The effect of crystallization temperature, nature of base and pH has been investigated. The prepared samples have been characterized by X-ray diffraction, thermogravimetry, scanning electron microscopy and nitrogen adsorption-desorption measurements. The effect of synthesis parameters is discussed in the light of characterization results.

IPC Code: Int. Cl.8 B01J29/00

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1840-1843

 

Synthesis and crystal structure of a nido 11-vertex diplatinaundecaborane cluster [(μ-PPh2)(PPh3)2Pt2B9H7-9, 11-(OiPr)2]

Li-Bin Wu, Jian-Min Dou*, Qing-Liang Guo Da-Cheng Li & Da-Qi Wang

Received 27 July 2005; revised 28 May 2006

The nido 11-vertex diplatinaundecaborane [(m-PPh2)(PPh3)2Pt2B9H7-9,11-(OiPr)2] (3) has been obtained by the reaction of [PtCl2(PPh3)2] with B10H102- in the presence of iPrOH under solvothermal conditions and characterized by elemental analysis, spectroscopic, and X-ray diffraction studies. The title cluster belongs to triclinic, space group Pī, with the crystal cell parameters: a = 12.622(4) , b = 13.439(5) , c = 17.926(6) ; a = 83.232(5), b = 75.952(4), g = 67.577(4). The title cluster (3) has a nido-eleven-vertex {Pt2B9} polyhedral skeleton with two Pt atoms at the neighbouring position of the open Pt2B3 face. Two Pt atoms are bridged by a PPh2 group. The H atoms at B(9) and B(11) positions are substituted by OiPr groups, respectively.

IPC Code: Int. Cl.8 C07F5/02; C07F15/00

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1844-1847

 

LSER and LFER in the reaction of benzimidazole with benzyl bromide

S Ranga Reddy & P Manikyamba*

Received 27 March 2006; revised 5 June 2006

The second order rate constants of the nucleophilic substitution reaction of benzyl bromide with benzimidazole have been obtained conductometrically in 11 different solvents in the temperature range 303 318 K. The rate constants are correlated with the polarisability (P) of the solvent and hydrogen bond acceptor basicity (b) of the solvent leading to a biparametric equation, log k = -7.86+20.23P +1.45b (n = 11, R = 0.93, SE = 0.08). Substituent effect on rate of the reaction suggests that both electron donating group (p-CH3) and electron withdrawing groups (p-NO2, p-Br) enhance the rate of the reaction compared to the unsubstituted compound. The substituted (p-NO2 and p-Br) and the unsubstituted compound form a linear free energy relationship.

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1848-1851

 

Voltammetric response of 2,4-D-molecularly imprinted film modified glassy carbon electrodes

Zhihua Wang, Jingwan Kang*, Xiaoyu Liu & Yongjun Ma

Received 31 October 2005; revised 26 April 2006

A novel voltammetric sensor has been developed by changing medium based on the molecular recognition of the template by imprinted technology. The sensitive layer has been prepared by electropolymerization of ortho-phenylenediamine and resorcinol on glassy carbon electrode in the presence of the template molecule. Cyclic voltammetry and a.c. impedance studies have been carried out to investigate the properties of the polymeric film. After the template extraction from the resultant solution, re-binding of 2,4-D has been done from 0.1 mol/L H2SO4 containing the analyte. The amount of bonded 2,4-D has been determined by differential pulse voltammetry. The sensor exhibits good sensitivity and reproducibility for 2,4-D by virtue of the interaction between molecularly imprinted binding sites and template.

IPC Code: Int. Cl.8 G01N27/00

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1852-1855

 

Solid phase extraction and spectrophotometric determination of platinum(IV) with N-(3,5-dihydroxyphenyl)-N-( 4-aminobenzenesulfonate)-thiourea

Zhigang Li , Xuemei Li , Liya Zhu , Qiufen Hu , Jing Chen & Guangyu Yang *

Received 30 December 2005; revised 18 May 2006

A highly sensitive, selective and rapid method for the determination of platinum(IV) based on its rapid reaction with N-(3,5-dihydroxyphenyl)-N-(4-aminobenzenesulfonate)-thiourea (DHPABT) and the solid phase extraction of the Pt(IV)-DHPABT complex with a polymer-based C18 cartridge has been developed. In 0.05 - 0.5 mol L-1 HCl medium, DHPABT reacts with platinum(IV) to form a violet complex of a molar ratio 1:3 (platinum : DHPABT). This complex is enriched by the solid phase extraction with polymer-based C18 cartridge and an enrichment factor of 200 has been obtained. The molar absorptivity of the complex is 1.01105 L mol-1 cm-1 at 760 nm, and Beers law is obeyed in the range of 0.01~3.0 mg mL-1. The relative standard deviation for eleven replicate analysis of 0.01 mg mL-1 solution is 1.86 %. The detection limit reaches 0.02 mg/L in the original samples. This method has been applied to the determination of platinum(IV) in water and soil samples. The relative standard deviation is 3.0-3.3%, and the standard recoveries are in the range 88-107%. The determined values agree with those obtained by ICP-MS method.

IPC Code: Int. Cl.8 G01N21/25; G01N30/00

 

Indian Journal of Chemistry

Vol. 45A, August 2006, pp. 1856-1860

 

Synthesis and characterization of a Hg(II) selective n-butyl acetate cerium(IV) phosphate as a new intercalated fibrous ion exchanger: Effect of surfactants on the adsorption behaviour

K G Varshney* M Z A Rafiquee, Amita Somya & Milan Drabik

Received 27 January 2006; revised 25 May 2006

n-Butyl acetate Ce(IV) phosphate, a new Hg(II) selective, intercalated fibrous ion exchanger, has been synthesized and characterized by its ion exchange properties, thermal stability and adsorption behaviour for metal ions, X-ray, IR, TGA/DTA and SEM studies. Effect of surfactants on the adsorption behaviour of the material has also been studied. The exchanger has been found to be selective for Hg(II). Hence, it can be utilized for the separation of this metal ion from other heavy metals from aqueous media. Studies on the effect of surfactants on the adsorption behaviour of this material show that for heavy metals ion, the adsorption increases with the concentration of anionic surfactants up to the CMC value and then decreases. But, for cationic surfactants, the reverse is true. For non-ionic surfactant, adsorption remains constant up to the CMC value and then increases. For alkaline earths, the exchanger shows the same trend as above for cationic and non-ionic surfactants. However, for anionic surfactants, it is constant throughout the whole concentration range.

IPC Code: Int. Cl.8 B01D15/04; B01J39/00