تحضير وتشخيص المشتق (2-(4- ميثوكسي فنيل) آزو (5,4 – ثنائي فنيل اميدازول)) وأستخدامه في التقدير الطيفي لايوني النحاس (II) والفضة (I) وتطبيقاته التحليلية

Preparation and Identification of (2-(4-methoxyphenyl)azo(4,5-diphenyl imidazole )) and use it for spectrophotometric determination of copper(II) and silver(I) and its analytical applications

The Study involves the synthesis and identification of a new azo-dye reagent via diazotization of 4-methoxy aniline and coupling of the formed diazonium salt with 4,5-diphenyl imidazole . The possibility of using the synthesized product as achromogenic reagent for (11) cation was investigated. The investigation shows the possibity of utilizing (2-(4-methoxyphenyl)azo (4,5-
diphenylimidazole)) reagent for spectrophotometric determination of Cu(II) and Ag(I) at pH 8 and 10 respectively in ethanol in medium. Different parameters that affect the absorption of Cu(II) complex at 507nm and Ag(I) complex at 525nm (namely, the pH volume. of reagent, time , temperature , type of buffer , order of addition and ionic strength ) were studied. Calibration curves of these complexes were constructed . Beer’s low was obeyed in the range (1.000×10^-7– 1.000×10^-6M) of Cu(II) with coefficient of linear (R²= 0.9989) and molar absorptivity ε=(0.7214×10⁴L.moL^-1.cm^-1) Sandell sensitivity was (0.009μg/cm²) as for Ag⁺, the range was (0.740×10^-7-1.480×10^-6M) coefficient of linear (R²=0.9987) and molar absorptivity ε =(0. 2516×10⁴L.moL^-1.cm^-1) , and
Sandell Sensitivity was (0.042μg/cm²) .The stoichiometry of the formd Cu(II) and Ag(I) complexes were investigated by the continuous variations method ,mole ratio, and mollerd method . The ratio (M:L) were formd (2:1)for to Cu(II)
complex at pH (8.0), and (1:1) for Ag (I) complex at pH (10.0) .The stability constants (Ksta) of the formed complexes were calculated and were equal to (Kst =4.091×10⁸)and (Kst=1.746×10⁵)for Cu²⁺ and Ag⁺ respectively

The thermodynamic function (ΔG,ΔH and ΔS) for both complexes were also Calculated . The study showed that reaction between Cu²⁺ and the reagent is exothermic ,while that for the formation Ag⁺ complexe is endothermic , The effect of the presence of diversi cation and anion which causes
interferace in the determination of Cu(II) and Ag (I) , as well as the possibility of masking of these ions by suitable masking agents was studied . Thus these ions interfere differently according to the nature and concentration of the intrudent ion . The electric charge of the dissolved complexes was identified by passing it on cationic and anionic resin to show that both complexes were non charged . Precision and accuracy of the analytical procedure investigated by using three different concentration for each ions , Values of the RSD% of Cu (II) were between (0.534-2.903%) where as the (Re)% were between(95.9%-92.06%) As for the Ag (I) the RSD% were between (0.864-1.737%) whereas
the(Re)% were between( 95.50%-92.02%) . was also calculated by measuring the (D.L) which was of (2.361×10^-6M )(0.0299μg/mL) for Cu(II) and (2.610×10^-6M) (0.0564μg/mL) for Ag (I) which proved the sensitivity of the method by using
this (MPAI) the physical properties of precipitants were studied through the establishment of melting point , solubility and molar conductivity as well as the measurement of infrared spectra and (C.H.N) , with the suggestion of structural formula of the formed complexes with the reagent (MPAI) The method was applied for the determination of the content of Cu(II) in tea leaves , and sample
of filling teeth for determination of the content of Cu(II), Ag(I) found that the method with high accuracy and sensitivity .