Solvent Extraction Method for Extraction Cd2+ ions as cations from aqueous media By use 2-[(4-Chloro-2-Methoxyphenyl) azo]-4, 5-diphenyl imidazole By S.K.Jawad*, Zainab A-Muttalib Kufa university-college of education for girls Abstract: Extraction experiments for Cd2+ ions from aqueous phase by ligand 2[(4-chloro-2-methoxyphenyl)azo]-4,5-diphenyl imidazole (4-ClMePADI) shows the optimum conditions for this extraction method was (pH=10) (15 minutes) shaking time and 20µg (1.8*10-5M) concentration of Cd2+ ions in aqueous phase. Organic solvents effect study shows there is not any linear relation between distribution ratio (D) for extraction of Cd 2+ ions and dielectric constant (ε)for organic solvents used but there is un effect for organic solvent structure on the extraction of Cd2+ ions and distribution ratio (D) values. Stoichiometric studies demonstrated the more probable structure ion pair complex extracted for Cd2+ was 1:1 [Cd (4-ClMePADI)]2+(Cl-)2. Thermodynamic study illustrated the complexation reaction between Cd2+ ions and ligand (4-ClMePADI) was exothermic reaction, as well as (ΔHex = -0.0471 KJmole-1) (ΔGex = -56.57 KJmole-1) (ΔSex = 180.6 JK-1mole-1).

1) Introduction: The excellent properties for azo compounds in general and particularly imidazole compounds open the door about widespread for application of these compounds for complexation reactions with metal ions and used this property for extraction and separation these metal ions. Mohamed et al (2001) [1] for extraction Zn and Cd by complexation with 2-(2benzimidazolylazo)-4-acetamidophenol, a phenoldiazenyl- containing ligand. Fan et al (1998) [2] synthesis new azo compound and used it for spectrophotometric determination of Nickel. Lenarcik et al (2003) [3] used imidazole derivatives for comparison the extraction process of Zn(II) and Ni(II) complexes. Giridhar et al (2004) [4] studied effect of alkyl group in 3methyl imidazolium derivatives on the extraction of uranium. Sven et al (2003) [5] used Imidazole Derivatives as a Novel Class of hybrid compounds. 1

Reginaldo et al (2001) [6] used complexes of ruthenium and iron with benzimidazole derivatives as simple model for proton-couplede electron transfer systems. Wenjiang et al (2002) [7] used imidazole derivatives as antifungal for inhibition of P450- Ibrahim et al (2006) [8] synthesis new imidazole ligand and studied it's complexes with Cobalt(II), Nickel(II) and Copper(II). Ruijnan et al (2006) [9], synthesis of chiral salen Zn(II) and its coordination with imidazole derivatives and amino acid ester derivatives. Ibtehaj (2005) [10] used different imidazole ligand derivatives for extraction of Cu and Ag. Alaa (2006) [11] used 2-[(α-Naphthyl) azo] -4,5-diphenylimidazole as a ligand for extraction of Cu &Ag in solvent extraction method. Zhijan et al (2004) [12] synthesis of dicationic Extended Bis- Benzimidazoles. Shushcng et al (2003) [13] studied the crystal structure of Hexakis (imidazole) Nieckel(II)0,0´-diphenyldithiophosphate[Ni(Im)6](ph2O2PS2)2 .

2 ) Experimental: Reagents and solvents were obtained from commercial sources and used as received. all absorption and spectrophotometric measurements were made using a single beam UV-visible spectrophotometer (shimadzu UV – 100 -02 ) and double beam UV – 1700 UV – visible spectrophotometer shimadzu . pHMeasurements were carried out using (Aschott Gerask) pH – meter Model 820, as well as for detection the structure of new ligand (4 – ClMePADI ) prepared used lege unicam SP3 – 2001 Infrared Spectrophotometer and C.H.N FA1108Elemental Analyzer.

2.1) Preparation of solutions: Stock solution of Cd2+ ions (1 mg \ml) was prepared by dissolved 1.631 gm of CdCl2 after dehydrated at 110ºC in water contain 2ml concentrated HCl acid and then complete the solution to (1 liter ) by distilled water in volumetric flask, but all other working solutions was prepared by dilution with distilled water, potassium _sodium terterate solution (20 %) was prepared by dissolved 20 gm of potassium _sodium terterate in distilled water by used (100 ml) volumetric flask, dimethyl glyoxime solution ( 1%) prepared by dissolved (1gm) of DMG in 100 ml methyl alcohol by used volumetric flask, hydroxylamine hydrochloride (10%) solution for determination of Cd2+ ions in aqueous phase prepared by dissolved (10gm) of hydroxylamine hydrochloride in (100ml) distilled water by used volumetric flask, (20%) solution of NaOH prepared by dissolved (20gm) of NaOH tablate in (100ml) 2

distilled water by used volumetric flask and then keep this solution in other working solution prepared by dilution with CCl4 this solution must be prepared instantaneously because this solution effect by environment and used for specterophotometric determination of Cd2+ ions in aqueous media , stock solution of ligand (4-ClMe PADI) (1*10-2 M) prepared by dissolved (0.3885 gm) in (100ml) of chloroform CHCl3 by used volumetric flask, other working solution prepared by dilution withCHCl3 .

2.2 General procedure: Performed Extraction experiments for Cd2+ ions in (10 ml) aqueous phase after precision the pH of aqueous solution at optimum value afterward added (10ml) of ligand solution (4-ClMePADI) dissolved in suitable organic solvent at fixed concentration , and then shaking the layers for suitable time in order to reach the equilibrium of complexation reaction , after that separate these two ayers and determine the remainder quantity of Cd2+ ions in aqueous phase and the quantity of Cd2+ ions transfered into organic phase and to form the ion pair association complex with ligand (4-Cl Me PADI),and for determination of Cd2+ ions in aqueous phase follow spectrophotometric determination method [14] which is include acidify a solution contain Cd2+ ions to (pH~2) and shake it with portions of the dithizone solution in CCl4 until the colour of the organic phase no longer changes. Discard the organic extracts.To the aqueous added (1ml) tartrate solution, 0.5ml of dimethylglyoxime solution, and ammonia till neutral.Allow to stand for 1min, then add 1ml of hydroxyl amine solution, and sufficient 20% NaOH to give a miuimum final NaOH concentration of 5% . Extract the cadmium with portions of dithizone in CCl4 until the extract is no longer pink with Cd(HD2)2, wash the combined organic extracts with 0.5% aqueous NaOH solution and water . Dilnte the pink solution with the solvent to the mark in a 50ml or smaller Volumetric flask, and measure its absorbance at 520nm against carbon tetrachloride as plank . from the absorbance and calibration curve figure (2) determine the quantity of Cd2+ ions remainder in aqueous phase after extraction procedure, and to determine the quantity of Cd2+ ions in organic phase following the stripping method by shaking the organic phase with three portions of (2ml) nearly concentration hydrochloric acid HCl after that collect these three portions and determine the quantity of Cd2+ ions according to previous method (14) afterward division the quantity of Cd2+ in organic phase over the quantity of Cd2+ ions in aqueous phase to determine the distribution ratio (D) for extraction of Cd 2+ ions and percentage of extraction (E), and could be determine the quantity of Cd2+ ions in organic phase by subtraction quantity of Cd 2+ ions in aqueous phase from initial quantity of Cd2+ ions in aqueous phase before extraction 3

2-3 preparation of ligand 4-Cl Me PADI: To amixture of (4.2gm) Benzil, (0.52gm) of hexamethylene tetramine and (12gm) of ammouium acetate adding (100ml) of glacial acetic acid, and then reflux for (1hour) , after chilling added (400ml) of distilled water, afterward precipitate the product which is imidazole derivative by addition of (0.88N)ammonium hydroxide at last filtered the product and wash it with distilled water and recrystalized the product in yridine. The second step prepare diazo compound or diazonium salt by dissolved 1.57gm of 4-cloro -2-methoxy aniline in 150ml ethanol to prepare amine solution, nitrite solution prepared by dissolved 2gm of NaNO2 in150ml distilled water and 1.5ml dilute hydrochloric acid (1:1) added drop by drop, needly prepare alcoholic sodium hydroxide solution by dissolved quantity of NaOH in solvent of (15ml alcohol+10ml distilled water) after that mixing the nitric solution with alcoholic sodium hydroxide, afterward added this mixture drop by drop to the amine solution with chilling to lower than (5ºC) to produce diazonium compound, the last step added diazonium solution drop by drop to the solution of imidazole at(-5ºC)wash the product with distilled water and recrystallized in (ethanol:water)

2-4 Spectrophotometric studies: To be sure of the structure of new ligand prepared(4-Cl Me PADI) by spectrophotometric methods, UV-Visible spectra shows three peaks, one peak at (233nm) for electronic transition π-π* for imidazole ring [15], second peak at (299nm) for electronic transition π-π* for benzen ring, third peak at (442nm) for Internal charge transfere(n-π*) this result identify with previous. Studies. Infrared spectra shows may peaks for stretching vibration for functional groups, strong peak at 3350cm-1 for (N-H) group in imidazole ring [15], three weak peaks appear at position 3050cm-1, 2995cm-1, 2885cm-1 for (C-H) aliphatic, aromatic and etheric [15,16], at1600cm-1 appear strong peak belong to (C=N) of imidazole ring, imidazole group shows two middle peak at 1450cm-1,1480cm-1 the peak appear at 700cm-1 belong to C-Cl group. Elements analysis shows the percentage of elements in ligand molecule identify with theoretical result (C= 67.95%) (H= 4.37%) (N= 14.41%). 4

Figure (1): Structure of Ligand 2-[(4-Chloro-2-methoxy phenyl)azo]-4,5-diphenyl imidazole 3) Result and discussion: 3-1) Effect of pH: Extraction of 30µg (2.6*10-5M) Cd+2ions in (10 ml) aqueous phase by (10ml) of (1*10-3M) ligand (4-ClMePADI) dissolved in chloroform at different pH(1-11) after shaking the two layers for suitable time afterward separate these two layers and determine the quantity of Cd +2ions remainder in aqueous phase at each pH and the quantity of Cd2+ions in organic phase, afterthat calculate distribution ratio (D) and percentage of extraction (E) according to previous method in general procedure. The result in Table (1) and Figure (3) shows the optimum pH for extraction of Cd2+ions was (pH=10) which is giving higher distribution ratio (D) and percentage of extraction (E),and this method shows the extraction in acidic solution effected to protonated ligand molecule and occupy the lone pair electron on the nitrogen atom which minimizing the ability of complexation reaction and decrease distribution ratio (D) and percentage of extraction (E), as well as in many basic media Cd2+ions produce stable species can not be extracted and decrease distribution ratio (D) and percentage of extraction (E) like CdCl2.H2O, CdCl2.2.5H2O, CdCl-3, CdCl+, CdCl42-,CdOHCl.

Table (1): effect of pH on the extraction of Cd2+ions

pH

1

2

3

4

5

6

7

8

9

10

11

D

0.85

0.89

0.95

1.12

1.26

1.45

1.94

2.29

2.77

5.45

3.65

E

45.9%

47.1%

48.7%

52.8%

55.8%

59.2%

66%

69.3%

73.5%

84.5%

78.5%

5

Absorbance(A)

2 1.5 1 0.5 0 0

10

µ gCd

2+

20

30

40

50

ions in 10ml aqueous phase

Figure (2): Calibration curve for Cd2+ ions

pH

Figure (3): Effect of pH on the extraction of Cd 2+ ions 6

3.2) Effect of Cd2+ ions concentration in aqueous phase: Make extraction experiments for (10 ml) aqueous phase contain different quantity of Cd2+ ions (5 – 50 µg) 4.45*10-6 M – 4.45*10-5 M by (10 ml) ligand solution (4-ClMePADI) dissolved in chloroform at (1*10-3 M) concentration at optimum pH (pH = 10), after shaking the two layers for suitable time separated organic phase from aqueous phase and determine the remainder quantity of Cd2+ ions in aqueous phase and the transfered quantity of Cd 2+ ions to organic phase to giving ion pair association complex afterward calculate distribution ratio (D) and percentage of extraction (E) for extraction of Cd2+ ions at each quantity of Cd2+ ions in aqueous phase according to previous method explained in general procedure. The results in Table (2) and Figure (4) shows the optimum concentration of Cd2+ ions in aqueous phase giving higher distribution ratio (D) and percentage of extraction (E) was (20µg) (1.8*1o5M) Cd2+ions. These results illustrated the important of metal ion concentration in aqueous phase to reach the equilibrium of complexation reaction according to the equilibrium below:

Cd2++n(4-ClMePADI) +2CI- ↔ [Cd(4-CIMePADI)n]2+ CI2aq. org. aq. org. The concentration of metal ion less than optimum value not allow to reach the equilibrium, but the concentration more than optimum value deviate the equilibrium to dissociation equilibria according to le schatleir principle.

Table (2): Effect of Cd2+ ions concentration on the extraction method.

µg Cd2+ 5

7

10

20

9

13.29 6.14 5.45

D

4

E

80% 90% 93%

30

40

50 9.82

86% 84.5% 73.8%

Log D

1.2 1 0.8 0.6 0.4 0.2 0 0

20

40

60

µ g Cd 2+ ions in 10ml aqueous phase

Figure (4): Effect of Cd2+ ions concentration on extraction method.

3.3- Effect of shaking time: From the kinetic side of extraction method there is an effect for shaking time of the two side layers aqueous phase contain metal ions and organic phase contain ligand which is immiscible in solvent extraction method, and to show this effect extracted (20 µg) (1.8*10-5M) Cd2+ions in 10 ml aqueous phase at (pH=10) by (10ml) ligand solution (4-CIMePADI) dissolved in chloroform at (1*10-3M) concentration at different shaking time (5-25 min), after complete shaking separate these two layers and determine the quantity of Cd2+ ions in aqueous and organic phase and calculate distribution ratio (D) and percentage of extraction (E) according to procedure detailed in general procedure. The results in Table (3) and Figure (5) demonstrate the optimum shaking time which allow to reach the equilibrium of complexation reaction was (15 minutes), shaking time less than 15 min not allow to reach equilibrium and decrease distribution ratio (D) as well as shaking for time longer than optimum time effect to dominate the dissociation equilibria.

8

Table (3): shaking time effect on extraction of Cd2+ ions Time (min.) 5 10 15 20 25 D 3.55 3.17 7.82 6.14 5.25 E 78% 76% 88.7% 86% 84%

1 Log D

0.8 0.6 0.4 0.2 0 0

10

20

30

Shaking time (minutes)

Figure (5): shaking time effect on the extraction of Cd2+ ions 3.4) Organic solvent effect: According to solvent extraction method there is un effect for the organic solvents used because the two layers used in this extraction method immiscible and the ion pair complex formed transfere and stable in organic solvent, according to this fact extracted (20 µg) (1.8*10-5M) Cd2+ ions in (10ml) aqueous phase at (pH = 10) by (10ml) ligand solution (4-CIMePADI) dissolved in different organic solvent differ in dielectric constant at (1*10-3M) concentration and then shaking these two layers for (15 minutes), separate these two layers and determine distribution ratio(D)and percentage of extraction(E)for each organic solvent used by methods detailed in general 9

procedure. The results in Table (4) shows there is not any linear relation between distribution ratio (D) and dielectric constant (ε) for organic solvents used but there is arelation with organic solvents structure, this relation giving higher distribution ratio (D) and percentage of extraction (E) with dichloromethane CH2Cl2 and chloroforme CHCl3. as well as this result suggest participation of organic solvent in the formation of ion pair association complex as contact ion pair (tight ion pair) or solvent separated ion pair (loose ion pair).

Table (4): Organic solvent effect on extraction of Cd2+ions Organic solvents CH2Cl2 CHCl3 C6H5Br C6H6 C6H5CH3 CCl4

ε

D

E

9.08 5.708 5.40 2.804 2.438 2.38

13.29 13.29 3.17 5.25 4.71 9.0

93% 93% 76% 84% 82.5% 90%

By application Born relation Calculate transition free energy of ions according to dielectric constant of organic solvent Z2  1 1    Gt  2r   w  0 

From the complexation equilibrium:

Cd2++n (4-ClMePADI) +2Cl-  [Cd (4-ClMePADI)n]2+Cl-2 Calculate association constant KA

 

[Cd (4  ClMePADI )]2 Cl  KA  [Cd 2 ][4  ClMePADI ]

2

In organic phase Cd2+ions concentration equal to the concentration of complex fromed. from the relation below calculate extraction constant. 11

K ex 

K AD[Cd (4  ClMePADI ) n ]2 2Cl org [Cd 2 ]aq [4  ClMePADI ]org

Free energy of extraction calculate from the relation below Gex   RT ln K ex

Table (5): Thermodynamic data by organic solvent effect Organic solvent CH2Cl2 CHCl3 C6H5Br C6H6 C6H5CH3 CCl4

ε

Gt

KA -1

9.08 5.708 5.4 2.804 2.438 2.238

KJmole L/mole -2*10-3 6*104 -3.4*10-3 7.1*104 -3.6*10-3 7.4*104 -7.2*10-3 6.7*104 -8.4*10-3 6.8**104 -9.14*10-3 6.2*104

Kex

Gex

7.39*108 7.39*108 1.76*108 2.9*108 2.6*108 4.96*108

J/mole -4.7*104 -4.7*104 -4.3*104 -4.47*104 -4.45*104 -4.59*104

Although the free energy of ionic transition appear decline with dielectric constant increase and association constant giving higher value with chloroform and bromobenzene but extraction experiments in different organic solvents shows maximum Kex and –ΔGex with CH2Cl2 and CHCl3 which is have not the same dielectric constant and CCl4 giving high value for Kex and –ΔGex in spite of the fact that have lower dielectric constant.

3.5) Stoichiometry: 3-5-1) Slope analysis method: Extracted (20 µg) (1.8*10-5M) Cd2+ ions in (10ml) aqueous phase at (pH=10) by (10ml) ligand solution (4-CIMePADI) dissolved in chloroform at different concentration (1*10-4M – 8*10-3M). After shaking for (15 minutes) separate the two layers and determine distribution ratio (D) and by application the method detailed in general procedure. The results in Table (6) and Figure (6) shows the structure of ion pair complex extracted was 1:1 [Cd(4-CIMePADI)]2+(Cl-)2. 11

Table (6): slope analysis method (4-CIMePADI) 8*10-3 5*10-3 3*10-3 1*10-3 8*10-4 5*10-4 3*10-4 D 4.41 4.26 4.0 1.58 1.44 1.25 0.72 slope 0.56

Log [4-Cl Me PADI]

Figure (6): slope analysis method

3-5-2) Mole ratio method: To affirmation structure of ion pair association complex extracted (20µg) (1.8*10-5M) Cd2+ ion in (10ml) aqueous phase at (pH=10) by (10ml) ligand solution contain different concentration of ligand (4-CIMePADI) dissolved in chloroform, after shaking for (15 minutes) and separate organic phase from aqueous phase determine the absorbance of organic phase at λ max = 490nm against ligand solution as planck, then calculate C L/CM value at different concentration of ligand (CL) where CM the constant concentration of metal ion, at last plot CL/CM against absorbance values. The results in Table (7) and Figure (7) 12

demonstrate the more probable structure of ion pair complex extracted was 1:1 [Cd((4-CIMePADI)]2+(Cl-)2.

Table (7): mole ratio method for extracted Cd2+ ion (4-CIMePADI) 3*10-4 5*10-4 8*10-4 1*10-3 3*10-3 5*10-3 8*10-3 CL/CM A

0.17 0.29

0.28 0.78

0.45 1.5

0.56 1.53

1.69 1.58

2.81 1.6

4.49 1.72

Absorbance

2 1.5 1 0.5 0 0

1

2

3

4

5

Cl\Cm C l/Cm Figure (7): mole ratio method for extraction of Cd2+ ion. 3-5-3) Contineous variation method: This experiment depend on prepare the same concentration solution (1*10-3M) for aqueous phase contain Cd2+ions and organic solution contain ligand (4-ClMePADI) dissolved in chloroform, afterward mixing different volume of the two solution to maximum volume (10ml) at (pH=10) after shaking the mixture for (15 minutes) and separate the two phases determine the absorbance of organic phase at wave length λmax =490nm against ligand solution as plank. The results at Table (8) and Figure (8) shows the more 13

probable structure of ion pair complex was 1:1 identify with the result in slope analysis and mole ratio method [Cd(4-ClMePADI)]2 (Cl-)2. Table (8): continuous variation method. Vm ml Vl ml A

1

2

3

4

5

6

7

8

9

9

8

7

6

5

4

3

2

1

1.1

0.44

1.04 1.31 1.49 1.7

1.86 1.79 1.6

Absorbanse

2 1.5 1 0.5 0 0

0.2

0.4

0.6

0.8

V /V

m total Vm\Vtotal,Vl\Vtotal Vl/Vtotal

Figure(8):continueous variation method

14

1

3-6 Thermodynamic studies: For demonstrate the effect of temperature on the extraction of Cd2+ions from aqueous phase by use ligand (4-ClMePADI) dissolved in chloroform, this experiment include extracted (20 μg) (1.8*10-5M) Cd2+ions in (10 ml) aqueous phase at (pH=10) by (10 ml) ligand solution contain ligand 4-ClMePADI dissolved in chloroform at (1*10-3M) at different temperature (5-40oC), after shaking of (15min.) separate the two layers and determine distribution ratio (D) and percentage of extraction (E) at each temperature according to the method detailed in general procedure. The result in Table (9) and Figure (9) shows the complexation reaction between Cd2+ ions and ligand (4-ClMePADI) was exothermic.

Table (9): temperature effect on extraction Cd2+ions Toc Tok 1/TokX10-3 D E

5 278 3.6 49 98%

10 283 3.5 26.3 96.3%

20 293 3.4 15.67 94%

30 303 3.3 8.13 89%

40 313 3.1 2.88 74.2%

To calculate extraction constant Kex by implementation the relation below D K ex  Cd 2 aq 4  ClMePADI org





Table (10): Extraction constant of Cd2+ions 1/TokX10-3 KexX107

15

3.6 27.5

3.5 14.8

3.4 8.71

3.3 4.57

3.1 1.62

1.8 1.6 1.4

logD

1.2 1

0.8 0.6 0.4 0.2 0 3.7

3.6

3.5

3.4

3.3

3.2

3.1

3

K*10 -3 1/T1/T º K*10

Figure(9): temperature effect on extraction of Cd2+ions 1.6 1.4

LogKex

1.2 1

0.8 0.6 0.4 0.2 0 3.7

3.6

3.5

3.4

3.3

fhgkjuyigjmng

3.2

3.1

3

1/T º K*10-3

Figure(10):Extraction constants for Cd2+ions

16

By application of Vant Hoff equation and Gibbs equation calculated enthalpy and entropy as well as free energy of extraction. LogK ex H  1 / T 2.303R

Slope 

 H 2.303R

Gex   RT ln K ex

Gex  H ex  TS ex

Table (11): Thermodynamic data for extraction of Cd2+ions Δ Hex -0.0421 KJmole-1

Δ Gex -56.57 KJmole-1

Δ Sex 180.6 J.K-1 mole-1

The values of enthalpy of extraction demonstrate the degree of electrostatic association between cation Cd2+ and ligand (4-ClMePADI) as well as shows the degree of approach one another, where the more approach one another giving more stable complex extracted, also the large radius of Cd 2+ions as well as the probable to giving stable species in aqueous phase effect to decrease the approach between Cd2+ions and ligand (4-ClMePADI) with temperature increase, and this results emphasize the participation of organic solvent in ion pair complex extracted as solvent separated complex (loose ion pair).

17

References: 1) G.G.Mohamed, Nadia E.A.EI-Gamel, F-Teixidor (Polyhadron 20 (2001) 2689-2696) complexes of 2-(2-benzimidazolylazo)4acetamidophenol, α phenoldiazenyl-containg ligand. 2) Xnezhong Fan, Guofang and Chunhua Zhu (Analyst 123 (1998) 109-112). Synthesis of 2-[2-(5-methylbenzothiazolyl)azo]-5dimethyl amino benzoic acid and its application to the spectrophotometric determination of Nickel. 3) Beniamin LENARCIK, Teresa RAUCKYTE and Agnicszka KIERZKOWSKA (XVIII-th ARS SEPARATORIA- Zloty potok, Poland 2003) the comparison of the extraction process of Zn(II) and Ni(II) complexes with 1-octylimidazole and 1-octyl-2-methyl imidazole. 4) P.Giridhar, K.A-Venkatesan, T.G-Srinivasan and P.R. Vandeva Ra (Journal of Nuclear and Radiochemical sciences Vol.5, No.2, PP. 2126, 2004) Effect of alkyl Group in 1-Alkyl-3-methylimidazolium Hexa fluorophosphate Ionic Liquids on extraction of Uranium by Tri-n-butyl phosphate Diluted with Ionic Liquids. 5) Sven GraBmann, Joachim Aplet, Wolfgang sippl, Xavie Lignean, Heinz H.Dertz, Yuan Hui Zhao, Jean-Michel Arrany, C-Robin Ganellin, Jean Charless Schwartz, Watler Schunack and Holger Stark. (Bioorganic and Medicinal Chemistry 11(2007) 2163-2174) Imidazole Derivatives as a Novel Class of Hybrid compounds with Inhibitory Histamine hH3 Receptor Affinities. 6) Reginaldo C.Rocha, Francisca N. Rein and Henriquc E.Toma (J.Branz. Chem. Soc. Vol.12, No.2, 234-242, 2001) Ruthenium and Iron complexes with Benzotrizole and Benzimidazole Derivatives as simple Models for proton-coupled Electron Transfer systems. 7) Wenjiang Zhang, Yamini Ramamoorthy, Tansel Kilicarslan, Helma Nolte, Rachel F-Tyndale and Edwared M. Sellers. (Drug metabolism and disposition Vol. 30, Issue 3, 314-318, March 2002) Inhibition of Cytochromes P450 by Anti fungal Imidazole Derivatives. 18

8) Ibrahim Irden, Nebahat Demirhan, UIVi Avcata (Synthesis and Reactivity in inorganic, Metal-organic and ManoMetal Chemistry Volume 36 Issu.7 PP. 559-562 August 2006) Synthesis and characterization of anew Imidazole Ligand and its complexes with Cobalt (II), Nickel (II) and Copper (II). 9) Ruijuan Yuan, Wenjuan Ruan, Shujun Wang Yinghui Zhang, Xia di Li, Zhiang Zhu (Journal of coordination chemistry volume 59, Issue 6 PP. 585-595 April 2006) Synthesis of Chiral salen Zn(II) and its coordination with imidazole derivatives and amino acid ester derivatives. 10) Ibtehaj Raheem Ali (thesis submitted to the college of Education for girls/Kufa university for Ms.c.) studies in Solvent Extraction of Cu and Ag by use of ligand, 2-[4-Carboxy methyl azo]-4,5Diphenyl imidazole an 2-[3-Methyl Benzen azo]-4,5-Diphenyl imidazole. 11) Alaa Khdhair Hassan (Thesis submitted to the college of Education for girls-Kufa University for Ms.c.) Solvent Extraction of Cu and Ag as cations by use of ligand 2-[α -Naphthylazo]-4,5diphenyl imidazole. 12) Zhijan Kany, Christine C. Dylastra and David W. Boykin (Molecules 9, 158-163, 2004) the synthesis of Dicationic Extended Bis- Benzimidazoles. 13) Shushing Zhang, Shiying Wang, Youghong Wen and Kui Jiao (Molecules 8, 866-872, 2007) synthesis and crystal structure of Hexakis (imidazole) Nickle(II) 0,0'-diphenyldithiophosphate [Ni (Im)6] (Ph2O2PS2)2 . 14) Z.Marczenko (copying by Allis horoo de limited 1974) separation and spectrophotometric determination of elements. 15) A.M. Hababan (Ph.D Thesis, university of Baghdad, College of sciences 1999) synthesis and application of complexation for different azo compounds with transition metal elements. 16) K.J. Khadumm Al-adely (Ph.D Thesis, university of Baghdad, College of sciences 2000) studies about complexes for transition metal elements with different azo compound and its derivatives. 19

‫االستخالص السائلي اليونات الكادميوم‪Cd2+‬من المحاليل‬ ‫الحامضية بأستخدام الليكاند‬

‫‪-4( ]-2‬كلورو‪-2-‬ميثوكسي فنيل) آزو[‪-5,4-‬ثنائي فنيل اميدازول‬ ‫شوكت كاظم جواد‬

‫‪,‬‬

‫زينب عبد المطلب‬

‫جامعة الكوفة كلية التربية للبنات‬

‫الخالصة‪:‬‬ ‫تجارب االستخالص اليونات الكادميوم ‪ Cd2+‬من المحاليل المائية بواسطة الليكاند ‪-4]-2‬‬ ‫كلورو‪-2-‬ميثوكسي فنيل)آزو [ ‪-5 , 4-‬ثنائي فنيل اميدازول )‪ (4-ClMePADI‬بينت ان القيمة الدالة‬ ‫الحامضية التي لالستخالص كانت )‪ (pH=10‬وان زمن الرج التالي للعملية هو (‪ 15‬دقيقة) كما ان‬ ‫التركيز االمثل أليونات الكادميوم ‪ Cd2+‬في الطور المائي كان ‪. ( 1.8*10 -5 ( 20µg‬اما دراسة‬ ‫تأثير المذيب العضوي على عملية االستخالص أظهرت انه ال توجد أية عالقة خطية بين نسبة التوزيع‬ ‫)‪ (D‬وثابت العزل الكهربائي (‪ )ε‬للمذيبات العضوية المستخدمة ‪ ,‬بينما هناك تأثير لتركيب المذيب‬ ‫العضوي على عملية االستخالص وقيم نسب التوزيع )‪ . (D‬دراسة تركيب معقد الترابط االيوني‬ ‫المستخلص اليونات الكادميوم ‪ Cd2+‬كان (‪. [Cd(4-ClMePADI)]2+(Cl-)2 )1:1‬باالضافة الى‬ ‫الدراسة الثرموديناميكية لعملية االستخالص أثبتت ان التعامل بين ايونات الكادميوم ‪ Cd2+‬والليكاند‬ ‫)‪ (4-ClMePADI‬كان التفاعل باعث للحرارة ‪ Exothermic‬وان القيم الثرموديناميكية كانت‬ ‫‪∆Hex=-0.0471 KJmole-1, ∆Sex=-180.6 KJmole-1 , ∆Gex=-56.57 Kjmole-1‬‬

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