Complex formation of vanadium(V) with 4-(2',3',4'-trihydroxyphenyl)-3-nitro-5-sulfoazobenzene (R) in the presence of cationic surfactants (CS), cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr), and cetyltrimethylammonium bromide (CTMABr), is studied. Vanadium(V) and R form a colored complex at a component ratio of 1 : 2 and pH of 5.0–5.5. The absorbance maximum of the complex is at 449 nm, while the reagent under these conditions absorbs light at 395 nm. In the presence of cationic surfactants, mixed-ligand complexes with a component ratio of V(V) : R : CS = 1 : 2 : 2 are formed, which results in a bathochromic shift of the absorbance maximum. Additionally, the pH value for the maximum complex formation shifts to a more acidic medium compared to the homoligand V(V)–R complex. The absorbance of the V(V) : R : CPCl, V(V): R : CPBr, and V(V) : R : CTMABr complexes is maximal at 457, 461, and 466 nm, respectively. The yield of these complexes is the highest at pH of 3.5–4.0 for VV(V) : R : CPCl and V(V): R : CPBr, and at a pH of 2.5–3.0 for V(V) : R : CTMABr. The formation of both homoligand and mixed-ligand vanadium(V) complexes depends on the reaction time, temperature, and concentrations of the reacting components. The determined stability constants indicate the high stability of the resulting mixed-ligand complexes. The specific conductivity of the complexes under the optimal conditions of complex formation was determined using conductometric titration. Calibration curves for the determination of vanadium(V) as homoligand and mixed-ligand complexes are linear. The effect of foreign ions and masking agents on the determination of V(V) as homoligand and mixed-ligand complexes was analyzed; it was shown that the presence of cationic surfactants significantly increases the selectivity of the reaction. An analysis of water samples from Lake Khanbulan, Lankaran District, Azerbaijan Republic using the developed procedure showed the presence of small amounts of vanadium(V).

Исследована возможность экстракции комплекса никеля(II) с 1-(2-алиламино-1-метилэтил)тиокарбамидом в присутствии и в отсутствие гидрофобных аминов- дифенилгуанидина и трифенилгуанидина. Установлено, что в присутствии гидрофобных аминов образуются смешанолигандные комплексы, хорошо растворимые в бутаноле-1. Извлечение комплексов происходит в течение 60 с, разделение фаз занимает 80 с. Однократной экстракцией извлекается до 96.7 и 98.0% никеля(II) в присутствии дифенилгуанидина и трифенилгуанидина соответственно. Установлены оптимальные условия образования и экстракции комплексов никеля(II) в присутствии и в отсутствие гидрофобных аминов. Определено соотношение компонентов в составе комплексов, установлен интервал линейности градуировочного графики для определения никеля(II) (0.10–2.80 мкг/мл) и получены уравнения градуировочных графиков по методу наименьших квадратов. Изучено влияние посторонних ионов и маскирующих веществ на экстракционно-спектрофотометрическое определение никеля(II) и установлено, что за счет образования смешанолигандных комплексов значительно увеличивается избирательность реакции. Разработана методика экстракционно-спектрофотометрического определения микроколичеств никеля в водах рек Акстафа и Джогаз Казахского района Азербайджанской Республики.

A possibility of extracting nickel(II) complex with 1-(2-allylamino-1-methylethyl)thiocarbamide in the presence and absence of hydrophobic amines, diphenylguanidine and triphenylguanidine, was studied. It was found that, in the presence of hydrophobic amines, mixed ligand complexes formed, which are readily soluble in 1-butanol. The extraction of complexes occurred within 60 s, phase separation took 80 s. A single extraction recovered up to 96.7 and 98.0

The effect of surfactants (CS) - chloride cetylpyridinium (CPCl), cetylpyridinium bromide (CPBr) and cetyltrimethylammonium bromide (CTABr) on the complexation of samarium (III) with 2,2',3,4-tetrahydroxy-3-sulfo-5'-nitroazobenzene (R)-investigated and optimal conditions for the formation of multiligand complexes were found. It was found that in the presence of cationic surfactants, multi-ligand complexes are formed with the ratio of the components Sm(III): R: CS = 1: 1: 1. The chemical-analytical characteristics of binary and multi-ligand complexes of samarium ( III) have been determined by the spectrophotometric method. Under optimal conditions for the formation of multi-ligand complexes, ligand-ligand interactions between the reactant and the CS were investigated and it was established that ionic associates with a 1: 1 ratio are formed. By the method of conductometric titration, the specific electrical conductivity of the complexes was investigated. A concentration interval obeying Beer's law has been established and the effects of foreign ions and masking substances on the determination of samarium(III) in the form of multi-ligand complexes have been studied. A method for spectrophotometric determination of samarium microquality in monocyte has been developed.

The interaction of Ti(IV) with 4-(2',3',4'-trihydroxyphenyl)-2-nitro-1-sulfoazobenzene (H3L) in the presence and in the absence of cationic surfactants (CAS) (cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr), cetyltrimethylammonium bromide (CTMABr)) was studied. The interval of concentration obeying Beer's law is established. In the complex formation of titanium(IV), the dependence A = f(C) is expressed by linear equations. The effect of time and temperature has been studied. The stability constants of binary and mixed-ligand titanium(IV) complexes were calculated. The ratio of the reacting components in the binary complex is 1:2, and in the mixed ligand 1:2:2. The effect of foreign ions and masking substances on the complex formation of titanium(IV) with reagents has been studied. Alkaline, alkaline earth and some transitional elements practically do not interfere to the determination. A technique has been developed for the spectrophotometric determination of titanium(IV) in aluminum-based standard samples

Complexation of bismuth (III) with 2,3,4-trihydroxy-4’-sulfoazobenzene in presence and in the absence of nonionic surfactant - Triton X-114 - is studied. An acidic environment (pH 2.5 - 3.0) promotes formation of ternary complex with a maximum light absorption at λ = 464 nm. Optimal conditions of complex formation are specified and the basic spectrophotometric characteristics of binary and ternary complexes of bismuth (III) are calculated. A new sensitive and highly selective method for determination of bismuth in pharmaceuticals and in standard samples of copper-based alloys is developed.

The complexation of gallium(III) with 2,2′,3,4-tetrahydroxy-3′-sulfo-5′-nitrobenzene in the presence of and without 1,10-phenanthroline was studied. In the presence of 1,10-phenanthroline, a mixed-ligand complex with the component ratio 1:2:1 and the stability constant logβ = 15.5 ± 0.2 is formed. The effect of pH, time, temperature, and the concentration of components on the formation of the binary and mixed-ligand complexes of gallium was studied. A procedure was developed for the photometric determination of gallium(III) in the presence of aluminum (III).

The effect of diantipyrilmethane and its homologues on the complexation of zirconium(IV) with 2,3,4-trihydroxiphenylazo-5′-sulfonaphthalene is studied, and conditions for the formation of mixed-ligand complexes are determined. Correlations between the acidity constants of diantipyrilmethane and its homologues and the stability constants and the specific conductivity of complexes, and degree of contrast, and the change in the Gibbs free energy are found for the complexation reaction. A method is developed for the selective photometric determination of zirconium in pyrite containing modified quartz diorite.

The complexation of molybdenum(VI) with Bromopyrogallol Red in the presence of the nonionic surfactant Triton X-114 is studied spectrophotometrically. A mixed-ligand complex is formed with the component ratio 1: 1: 1 and a stability constant of logβ = 8.2. The effect of pH, time, temperature, and component concentrations on the formation of the mixed-ligand complex is studied. A highly selective procedure for the spectrophotometric determination of trace molybdenum(VI) in drinking water in the presence of tungsten has been developed.

Procedures were developed for the photometric determination of tin(II) with pyrogallol azo compounds, 2,3,4-trihydroxyphenylazo-5′-sulfonaphthalene (R 1 ) and 2,2′,3,4-tetrahydroxy-3′-sulfo-5′-chlorazobenzene (R 2 ), in the presence of triphenylguanidine and bathophenantroline. The complexation of tin(II) with R 1 and R 2 was studied. It was found that different-ligand complexes formed in the presence of hydrophobic amines. A bathochromic shift in absorption spectra was observed along with shifts of optimum pH formation. The effect of reagent concentration, time, and temperature on the formation of different-ligand complexes was studied, and their stoichiometry was determined by different methods. It was shown that the determination of tin(II) with R 2 in the presence of the third component is highly selective. The developed procedures were used for the photometric determination of tin in Caspian Sea water.

The formation of niobium(V) and tantalum(V) complexes of 2,3,4-trioxyphenylazo-5-sulfonaphthalene in the presence of cetyltrimethylammonium bromide was studied by spectrophotometry. The effect of surfactants on the chemical and analytical properties of niobium(V) and tantalum(V) complexes of this reagent was studied. Procedures were developed for the spectrophotometric determination of niobium and tantalum present simultaneously as mixed-ligand complexes. The procedures were tested on model solutions.

An extraction method for separation of iron(III), copper(II), and cobart(II) is described; subsequently, these elements are analyzed by atomic-absorption spectrophotometry in an extract - acetone mixture (1 : 1). The potential use of N-(1-phenyl-2,3-dimethylpyrazolone-5)-C-(1-phenyl-3-methylpyrazolone-5)-phenylazomethine as a new extractant for Fe(III), Ni(II), Mn(II), Co(III), Cr(III), Cu(II), and Zn(II) is considered. Conditions for complexation of iron(III), copper(II), and cobalt(II) are specified and an extractive atomic-absorption method for analysis of these elements in copper alloys is proposed.