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Interaction of copper (II) with 1-(2-thenoyl)-4-trifluonne-2-[2-hidroxy-3-carboxy-5-sul-phophenylazo]butadion-1,3 in the presence of cationic surfactants
R. Aliyeva, F Aliyeva, R. Sulkhnedjad, F. Chiragov
исходит взаимодеиствие пероксиднои группировки молибдена с иодид-ионами. Показано, что катализ на основе ГПС Na2H7SmMoW9O36 протекает в нейтральной среде. Определены константы скоростей всех стадий процесса.
Список использованных источников
1. Панов М. Ю. Кинетика реакции окисления иодид-ионов пероксидом водорода. СПб.: ВВМ, 2002. С. 10-14.
2. Бусев А. И. Аналитическая химия молибдена. М.: Изд. АН СССР, 1962. С. 155-243.
Информация об авторе
• Нагиев Р. С. // студент IV курса химико-технологического факультета СурГУ ХМАО-Югры, г. Сургут
The complexation of copper (II) with 1-(2-thenoyl)-4-trifluo-rine-2-[2-hidroxy-3-carboxy-5-sulphophenylazo]butadion-1,3 in the presence of cationic surfactants — cetylpyridinium chloride, cetylpyridinium bromide, cetylpyridinammonium bromide is studied by photometric method. And also it is established in the presence of surfactants, that optimal conditions of complexation improved, complexation displaced to the acidic area and with increasing of the stability of associates detection limit of copper decreased. The influence of foreign ions and masking compounds on the complexation is learned. The technique of photometric determination of copper (II) in aluminum alloys is worked out.
Literature data has shown that surfactants have great influence on acidic properties of polydentant chromophores and increase their chemical-analytical properties [1,2]. Therefore, the complexation of copper (II) with 1-(2-thenoyl)-4-triflu-orine-2-[2-hidroxy-3-carboxy-5-sulphophenylazo] buta-dion-1,3 in the presence of cationic surfactants is investigated and high selective technique of photometric determination of copper (II) in aluminum alloys is worked out.
Experimental section The reagent is synthesized by known technique [3]. Composition and structure are determined by element analysis of IR and NMR spectroscopy. The formula of reagent is:
Standard 1-10"1 M solution of copper (II) was prepared from metallic copper (99,9%), corresponding to technique [4]. Work solutions were prepared by dilution of standard
ho3s
CF3
'=o
(OVN=N-?H
/-' c=o
HOOC OH
solution with distilled water. 110-3 M solution of reagent — 1-(2-thenoyl)-4-trifluorine-2-[2-hidroxy-3-carboxy-5-sulphophenylazo] butadion-1,3 (R) and 110-2 M solutions of surfactants — cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr), cetylpyridinammonium bromide (CPAmBr) were prepared by dissolving of corresponding amounts in water. For necessary acidity they used acetate-ammoniac buffer solutions (pH 3-11) and standard solution of HCl (pH 0-2). All used reagents are pure for the analysis.
Ph titration in aqua solution is used for determination of dissociation constant of reagent. Volume of 2-10"3 M of titrated solutions is 50 ml. Ionic strength (0,1) is kept with calculated amount of KCl. 4-10-2 M KOH solution, freed from carbonic acid, is used as titrant. For calculation of dissociation constant of reagent they used the equation [5].
Acidity of solutions were controlled with ionomer I-130 with glass electrode ESL-43-07, tuned with standard buffer solution. Optical density of solutions was measured on spectrophotometer Lambda-40 (Perkin Elmer) and on photo colorimeter KFK-2 in ditch with thickness of 1 sm.
Results and discussion In this article is shown that azoderiva-tives of acetyl acetone can exist at least in three tautomer forms. By IR,NMR and X-ray electron spectroscopy it was established that hydrazine form is more preferable because of its three
Химические науки
conjugate binary bonds and intramolecular hydrogen bond [7].
Stability constants were calculated pKt =4,17+0,01; pK =5,37+0,03; pK3 =8,78+0,02.
During the interaction of copper (II) with reagent the colored complex compound forms with maximum lightabsorption at ^=473 nm. Maximum yield of the complex is at pH 4,0. In this medium the reagent is absorbed at X=394 nm. In the presence of surfactants differentligand complexes Cu(II)-R-surfactant are formed and the bathochromic shift is observed on the comparison with spectrum of binary complex and maximum yield moves into more acidic medium. Lightabsorption of complexes Cu(II)-R- CPCl, Cu(II)-R-CPBr, Cu(II)-R- CPAmBr is maximal at X=481, 488 and 492 nm, correspondingly. Maximal yield of defferentligand complexes is observed at 3,0;c2,0; 2,0, correspondingly.
For determination of optimal conditions of formation of differentligand complexes the influence of concentration of reagents, temperature and time was studied. So, it found that yield of all differentligand complexes is maximal at 8,0-10" 5 M R and 8,0'10"5 M of surfactant, correspondingly. Binary and all differentligand complexes of copper(II) form instant after mixing of solutions of components and they differ from each other by their stability. In this way, in case when binary complex is stable during 5 hours at heating to 60°C, differentligand complexes are stable during one week at heating to 80°C.
Ratio of reagents in formed colored compounds is determined by isomolecular series method relatively to Starik-Barbanel's yield and equilibrium's shift [8]. Results of all methods show that ratio of components in binary complex is equal to Cu(II)-R=1:2 and in differentligand complexes it
Table 1. Chemical-analytic characteristics of copper(II) with 1-(2-thenoyl)-4-trifluorine-2-[2-hidroxy-3-carboxy-5-sulphophenylazo] butadion-1,3 in the presence of surfactants
Complexes PHopt Amaxnm AX,nm Ration of complexes, M:R:surfactant E'10-4 Obedience to Beer's law, Mg/ml lg ß
Cu(II)-R 4,0 473 99 1:2 2,5±0,13 0,20-2,56 4,64±0,05
Cu(II)-R- CPCl 3,0 481 104 1:2:2 3,0±0,12 0,18-3,07 5,25±0,07
Cu(II)-R- CPBr 2,0 488 100 1:2:2 3,3±0,10 0,12-2,56 5,32±0,06
Cu(II)-R- CPAmBr 2,0 492 102 1:2:2 2,8±0,11 0,12-2,56 5,14±0,08
Table 2. Characteristics of systems R-surfactant at optimal medium of complexation (Xn — 393 nm, R:surfactant= 1:1, pH 2,0; 3,0)
Cationic surfactant 4urf,nm ^surf-R,nm Lg K
CPCl 252 405 2,60±0,02
CPBr 250 408 2,67±0,02
CPAmBr 206 418 2,48±0,05
Table 3. Results of cunductometric titration of cationic surfactant's solution with reagent at pHopt (X10-4 OM-1 sm-1 )
VR ml Surfactant 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0
CPCl 3,63 3,68 3,57 3,53 3,52 3,49 3,48 3,48 3,48 3,48
CPBr 3,68 3,62 3,59 3,56 3,55 3,53 3,51 3,51 3,49 3,49
CPAmBr 3,74 3,71 3,69 3,66 3,64 3,60 3,60 3,58 3,58 3,57
Table 4. Admissible parities of foreign compounds to copper (II) during its determination in the form of homogenous and mixed ligand complexes (error 5%)
Ions or compounds R R+ CPCl R+ CPBr R+ CPAmBr Pycramine epsilon 5-(2-hydroxy3,5-dinitrophenilazo)-N-hyrdoxy-8-hydroxychinoline [10]
Na(I) 1796 1796 1800 1796
K(I) 3046 3046 3060 3046
Mg(II) 38 95 110 90
Ca(II) 188 260 280 265
Ba(II) 214 840 970 830
Zn(II) 508 512 705 525 200
Cd(II) 875 1030 1205 1100 200
Mn(II) 9 140 180 140 10
Co(II) 461 480 510 480
Ni(II) 277 390 420 420 25
Fe(III) interferes 15 25 20
La(III) 217 320 360 360
Er(III) 261 325 375 345
In(III) 180 340 345 340
Ga(III) 160 320 335 320 60
Sn(III) 19 250 290 260
Mo(VI) 85 220 270 246 3
Bi(III) 33 160 210 170
W(VI) 120 390 470 480 100
C2O4- 9 80 95 75
Lemon acid interferes 95 102 70
thyourea 10 320 320 310
Na2HPO4x12 H2O 40 310 330 305
Wine acid 20 240 240 220
F- 56 85 90 70
Всероссийский журнал научных публикаций, апрель 2011
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is equal to Cu(II)-R-Surfactant= 1:2:2. For finding out the chemism of complexation of Cu(II) with the reagent in the presence and absence of surfactants Astakhov's method was used [9]. There is established that in all cases the dependence lg(AA/AAmax-AA) on pH in the interval of pH 3-4; 2-3; 1-2 angle's tangent is 2.
By method of crossing curves stehiometry and stability constant of binary complex Cu(II)-R is determined.
The results, found by above mentioned methods during the determination of stehiometry, are confirmed and it found that lgP=4,64±0,05. Stability constants are determined, considering the molar ratio of components in differentligand complexes. It is established that in the presence of surfactants stability constant considerably increases: lgp (Cu(II)-R-CPCl)= 5,32+0,07; lgp (Cu(II)-R- CPBr)=5,25±0,06; lgp (Cu(II)-R- CPAmBr)= 5,14+0,08. Molar lightabsorption coefficients of the complexes are Cu(II)-R,Cu(II)-R-CPCl, Cu(II)-R- CPBr, Cu(II)-R- CPAmBr at X t are equal to (2,5+0,73)-104; (3,3+0,12)-104; (3,0+0,10)p104; (2,8+0,11)104 .
As we can from the table 1, chemical-analytical characteristics of complex Cu(II) with reagent increase in the presence of surfactants. Therefore, for studying of influence of surfactants on complexation ligand-ligand interaction in the system R-surfactant has been investigated. With that end in view the reagent's absorption spectrums were taken in the presence of surfactants at pH 2-3.
It is established, that in the presence of surfactants batho-chromic shift in lightabsorption's spectrum is observed (table 2). It is known, that cationic surfactant is in cationic form in the solution and interacts with reagent electrostatically,and forms ionic associates. Stehiometry and stability constant of associate is determined by crossing curves method and results are shown in table 2.
Regent in acid medium (pH 0-3) is ni molecular form (pKj =4,17+0,01) and because of this at pH 2-3 ionic associates with ratio of components R:surfactant=1:1 form at the expense of electrostatic interaction of sulphogroup and surfactant. Maximum delocalization of n-electron system of reagent leads to bathochromic shift of absorption zone of formed associate, what is also related to increasing of negative induction effect of sulphogroup under the influence of cati-onic surfactants. As we can see, stability constant decreases among R- CPCl> CPBr> CPAmBr. Comparison chemical-analytical characteristics of associates and differentligand complexes show that with increasing of stability constants of associates the stability constants increase too, molar lightabsorption coefficient and contrast of reaction of differentligand complexes' formation.
Specific electrocunductivity of associates R-cationic surfactants was determined with conductometric titration (table 3). We see that electroconductivity of associates and their complexes' with copper (II) increases among: R- CPCl> CPBr> CPAmBr, where their stability constant decreases.
Influence of foreign ions and masking agents on photometric determination of copper as homogenous and mixed ligand complexes was studied (table 4). During the compari-
son of selectivity of known reagent [10,11] for determination of copper (II) we can see that the reagent synthesized by us in the presence of third component is moiré selective than others.
Worked out technique of photometric determination of copper (II) in different ligand complexes with 1-(2-thenoyl)-4-trifluorine-2-[2-hidroxy-3-carboxy-5-sulphophenylazo] butadion-1,3 in the presence of surfactants was applied for determination of its microquantity in aluminium alloys.
Determination of copper (II) in aluminium alloys Certain quantity of the alloy's sample was diluted in the mixture of 2 ml HF + 2 ml HCl+ 2 ml HNO3 + 10 ml H2O. The received paste has been processed three times with 3-4 ml HNO3 at 60-70°C to full distillation of HF. Precipitate is dissolved in water, filtered, transferred to a flask with volume 50 ml and diluted with water to a mark. The received solution (1 ml) is transferred to a flask with volume 25 ml and then they add 2 ml of 110-3 M solution of reagent (R), 2 ml 110"2 M CPCl, 1 ml 110-1 M NH4 F and then dilute with buffer solution (pH 2) to a mark. Optical density of solutions is measured at X= 490 nm in ditch of 1 cm on the KFK-2, concerning a solution of control experience. Results of determination of copper(II) in aluminium alloys are shown in table 5.
Table 5. Results of determination of copper (II) in aluminium alloys (n=3, p=0,95)
Standard sample of alloy The copper maintenance under the passport, % Photometric method
Xcu Mg/ml X±
A 195-3 0,14 1,13 0,14±0,001
A 195-4 0,11 0,88 0,11±0,002
A 194-5 0,04 0,32 0,04±0,002
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Authors
• R. Aliyeva // Baku Stare University, chemistry department.
• F. Aliyeva // Baku Stare University, chemistry department.
• R. Sulkhnedjad // Baku Stare University, chemistry department.
• F. Chiragov // Baku Stare University, chemistry department.
