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).

A novel reagent derived from salicylaldehyde has been synthesized and characterized by determining its crystalline structure through X-ray diffraction analysis. The complex formation of this reagent with iron(III) has been investigated by spectrophotometric methods. The dissociation constant of the reagent was determined by potentiometry in an aqueous–ethanolic medium, yielding pK = 9.66 ± 0.02. The interaction of iron(III) with 2-(((1-(3-bromophenyl)ethylidene)hydrazono)methyl)phenol in the presence and absence of diantipyrylmethane (DAM), diantipyrylphenylmethane (DAPhM), and diantipyrylpropylmethane (DAPrM) has been thoroughly studied. Optimal conditions for complex formation (λopt, pHopt) were found. Iron(III) forms colored mixed-ligand complexes with the reagent in the presence of the third component—DAM, DAPhM, or DAPrM,—resulting in a hypsochromic shift in the absorption spectrum. The maximum yield of complexes was achieved in a more acidic medium compared to the binary complex. Molar absorption coefficients of the complexes and the ranges of compliance with Beer’s law were determined. Component ratios in the homogeneous and mixed-ligand complexes were established using isomolar series methods, as well as the relative yield of the Starik–Barbanel and equilibrium shift methods. These analyses revealed that the component ratio of Fe(III)–R in the binary complex is 1 : 2, while in the mixed-ligand complexes Fe(III)–R–DAM, Fe(III)–R–DAPhM, and Fe(III)–R–DAPrM, the ratios are 1 : 2 : 1, 1 : 1 : 1, and 1 : 1 : 2, respectively. The mixed-ligand complexes of iron(III) with 2-(((1-(3-bromophenyl)ethylidene)hydrazono)methyl)phenol exhibit favorable chemical-analytical characteristics. The developed procedure was successfully applied to the determination of trace amounts of iron(III) in oil sludge.

This article presents the results of a study of the complex formation of samarium(III) with 3-(2-hydroxy-3-sulpho-5-(nitrophenylhydrazo)pentan-2,4-dione (R) in the presence and absence of surfactants: cetylpyridinium chloride (СPСl), cetylpyridinium bromide (СPBr), cetyltrimethylammonium bromide (CTMABr). The ratio of the reacting components in the composition of the same- (1:2) and mixed-ligand (1:2:2) compounds was established. The range of compliance with Beer's law was determined. The specific electrical conductivity of the studied complexes was studied by the method of conductometric titration. A technique for the photometric determination of samarium in monazite has been developed. The acidity of the solutions was monitored on an I-130 ion meter with an ESL-43-07 glass electrode. The optical density of the solutions was measured on a LAMBDA-40 spectrophotometer (Perkin Elmer) and a KFK-2MP photocolorimeter in a cuvette with a layer thickness of 1 cm. The specific electrical conductivity of the solutions was measured on a Mettler Toledo conductometer. It was found that in the presence of third components analytical parameters of mixed-ligand complexes. Results of investigation were used for determination of Sm(III) in monacite

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.

The effect of the third components of cationic surfactants – chloridecetylpyridinium (CPCl), cetylpyridinium bromide (CPBr), cetyltrimethylammonium bromide (CPMABr) for complexation of nickel (II) with 4- (2´, 3´, 4´-trihydroxyphenyl) -3-sulfo-5-chlorophenylazo benzene (R). Same- (NiR) and mixed-ligand complex compounds (Ni (II) -RCPCl, Ni (II) -RCPBr and Ni (II) -RCPMABr) are formed at pH 6, 4, 4 and 4, respectively. All complexes are formed immediately after mixing the solutions of the components and differ in stability. The ratio of the reacting components in the composition of same- (1: 1) and mixed-ligand (1: 1: 1) complexes are established. The interval of obedience to Beer's law is determined. The coefficients of the calibration curve equation are determined by the method of least squares. Complexation of nickel (II) is expressed by linear dependence of A = f (c) is. Stability constants of same- (NiR) and mixed-ligand complexes (Ni (II) -RCPCl, Ni (II) -RCPBr and Ni (II) -RCPMABr) are calculated. Under optimal conditions of complexation, Ni-R was titrated with a solution of third components (CPCl, CPBr and CPMABr) by conductometric method. The influence of foreign ions on complexation of nickel (II) with R in the absence and in the presence of third components was studied. A technique has been developed for the spectrophotometric determination of microquantities of nickel in the waters of the Akstafa and Jogaz rivers of the Kazakh region of the Republic of Azerbaijan

Porous silicon is actively used in the fabrication of sensors and detectors because of its large specific surface area, which is an important characteristic for gas adsorption. To improve the operating parameters of the sensors and increase the stability of operation, a film of tin oxide was deposited on the substrate of porous silicon by vacuum-thermal evaporation. The choice of tin is due to its wide forbidden zone, low cost, and high sensitivity. Porous silicon was obtained by the electrochemical anodization of single-crystalline silicon KEF (100). The data on morphology, composition and optical properties of the initial sample of porous silicon and the sample with deposited tin have been obtained by scanning electron microscopy, infrared and photoluminescence spectroscopy. It was found that the chemical tin deposition on porous silicon leads to the formation of composite structure, which significantly prevents further oxidation of the porous layer during storage, and to the shift of the luminescence band maximum

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

Министерство науки и высшего образования Российской Федерации Российская академия наук Научный совет по неорганической химии РАН Научный совет по аналитической химии РАН Научный совет по химической технологии РАН Российское химическое общество имени Д.И

The effect of the third components of cationic surfactants - chloridecetylpyridinium (CPCl), cetylpyridinium bromide (CPBr), cetyltrimethylammonium bromide (CPMABr) for complexation of nickel (II) with 4- ( 2', 3', 4'-trihydroxyphenyl) -3-sulfo-5-nitrophenylazo benzene (R). Same- (NiR) and mixed-ligand complex compounds (Ni (II) -RCPCl, Ni (II) -RCPBr and Ni (II) -RCPMABr) are formed at pH 6, 3, 3 and 4, respectively. All complexes are formed immediately after mixing the solutions of the components and differ in stability. The ratio of the reacting components in the composition of same- (1: 1) and mixed-ligand (1: 1: 1) complexes are established. The interval of obedience to Beer's law is determined. The coefficients of the calibration curve equation are determined by the method of least squares. Complexation of nickel (II) is expressed by linear dependence of A = f (c) is. Stability constants of same- (NiR) and mixed-ligand complexes (Ni (II) -RCPCl, Ni (II) -RCPBr and Ni (II) -RCPMABr) are calculated. Under optimal conditions of complexation, Ni-R was titrated with a solution of third components (CPCl, CPBr and CPMABr) by conductometric method. The influence of foreign ions on complexation of nickel (II) with R in the absence and in the presence of third components was studied.

We studied the complexation of titanium(IV) with 2,2',3,4-tetrahydroxy-3'-nitro-5'-sulfoazobenzene (R) in the presence of cationic surfactants (CSs) cetylpyridinium chloride (CPCl), cetylpyridinium bromide (CPBr), and cetyltrimethylammonium bromide (CTMABr). In the presence of cationic surfactants, mixed-ligand complexes are formed with the ratio of components $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ : H4R– : CS = 1 : 2 : 2. The optimal pH values of the complex formation were found: 4.5 for ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2 and 3.5 for mixed-ligand complexes ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2(CPCl)2, ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2(CPBr)2, and ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2(CTMABr)2. We also investigated the effect of time, temperature, and concentrations of the reacting components on the formation of mixed-ligand complexes. The Beer law is observed in the concentration range of ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2, ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2(CPCl)2, ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2(CPBr)2, and ( $${\text{Ti}}({\text{OH}})_{{\text{2}}}^{{{\text{2}} + }}$$ (H3R2–)2(CTMABr)2 of 0.10–1.8, 0.10–1.92, 0.10–1.92, and 0.08–1.92, respectively. The effect of foreign ions and masking substances on the determination of titanium(IV) as mixed-ligand complexes was studied. We developed a procedure for the spectrophotometric determination of trace amounts of titanium in sea sand taken from the Caspian Sea coast near the Turkan village.

A new copper(II) complex with bis(4,4′-(ethane-1,2-diylbis(azanediyl))bis(3-(2-(4-fluorophenyl) hydrazinyl)pentan-2-one) (1) is synthesized and analyzed by single crystal X-ray diffraction. The crystals are monoclinic: a = 11.1340(9) Å, b = 11.6716(10) Å, c = 18.7797(16) Å, β = 94.792(2)°, V = 2431.9(4) Å3, space group P21/n, Z = 4, ρcalc = 1.713 mg/m3, R = 0.0695. The environment of the copper atom is formed by four donor nitrogen atoms (N1, N3, N4, N6). These atoms are at the equatorial position. The N6 atom slightly deviates from the middle plane. Phenyl rings are not involved in the coordination. Additional crystallographic data are available from the Cambridge Crystallography Data Center under number CCDC 1907359.

Синтезирован новый комплекс меди(II) с бис(4,4'-(этан-1,2-диилбис(азанедиил))бис(3-(2-(4-фторфенил)гидразинил)пентан-2-оном) (1) и проведен его рентгеноструктурный анализ. Кристаллы моноклинные: a = 11.1340(9) Å, b = 11.6716(10) Å, c = 18.7797(16) Å, β = 94.792(2)°, V = 2431.9(4) Å3, пространственная группа P21/n, Z = 4, ρвыч = 1.713 мг/м3, R = 0.0695. Окружение атома меди сформировано четырьмя донорными атомами азота (N1, N3, N4, N6). Эти атомы находятся в экваториальной позиции. Атом N6 чуть отклоняется от средней плоскости. Фенильные кольца не принимают участия в координации. Дополнительные кристаллографические данные доступны из Кембриджского центра кристаллографических данных под номером CCDC 1907359.

The complex formation of iron(III) with 3-((2-hydroxyphenyl)diazenyl)pentadione-2,4 and diantipyrylmethane was investigated by spectrophotometric method and highly selective method of determination of its microamounts in natural objects established.It's found that at pH 2.0-2.5 in the presence of diantipyrylmethane Fe(III) forms with reagent intensively colored mixed-ligand complex Fe(III)-R-DAM with the ratio of components 1:2:1.During formation of mixed-ligand complex bathochromic shift and hyperchromic effect are observed compared to binary complex.The optimum conditions of formation of same and mixed-ligand complexes of Fe(III) were determined and the main spectrophotometric characteristics calculated.By spectrophotometric method stability constants of complexes are determined and found that mixed-ligand complex Fe(III)-R-DAM has high stability: lgβ(Fe-R)=5.76±0.10;lgβ(Fe-R-DAM)=14.65±0.26.The new highly selectivity spectrophotometric method for the determination of iron(III) has been developed and applied for the determination of its quantity in volcanic mountain rocks.

In a present paper methods of concentration of Ce(III) from aqueous solutions onto synthetic polymer adsorbent. The sorption-photometric determination of the microquantities of cerium ions by new polymeric chelating sorbent, modified with dithizone has been studied. Sorption process was carried out under static conditions. Optimal characteristics of the sorption process: influence of pH, time of contact, effect of the initial concentration of metal, influence of ionic strength were studied. pH for extracting Ce is 5; the residence time is 210 min. Optimal ionic strength was achieved at a value of μ =0.6. The sorption capacity of the sorbent and the percentage recovery were determined from the difference in the initial and final concentrations of cerium(III) in the solution. The sorbability of cerium(III) ions was 91.38%, sorption capacity of sorbent with respect to cerium ions is 682.85 mg∙g-1. At the final stage, a desorption process was carried out using different (organic and mineral) acids with the same concentrations (0.5, 1.0, 1.5, and 2.0 M). 1M HCl has the highest eluting ability with respect to cerium (III) ions. Sorbent modified with dithizone based on a styrene-maleic anhydride (SMA) copolymer is proposed as synthetic sorbent with the best analytical properties (high sorption capacity, residence time 3 h with respect to cerium ions). Multiple use of the regenerated sorbent for concentration is possible. The developed techniques can be used to determine Ce(III) in standard samples, soil and tap water.

4-(2, 4-bis((2-aminoethyl)-imino)pentane-3-yl)diazenyl)benzoic acid was synthesized using 3-[4-carboxyphenylazo]pentanedione-2,4 (R) reagent obtained by the standard procedure. The composition and structure of the synthesized reagent is determined by the methods of elemental analysis and NMR spectroscopy. The complexation of copper (II) with 3-[4-carboxyphenylazo]pentanedione-2,4 (R) in the presence and in the absence of 8-hydroxyquinoline, diphenylguanidine and ethylenediamine was studied spectrophotometrically. Optimal conditions for complexation are specified and composition of homo- and mixed-ligand complexes are determined. When copper (II) interacts with R at pH 3 – 10, the maximum yield of the complex compound is observed at pH 5 λ max = 553 nm. The molar absorption coefficients and the stability constants of copper (II) complexes were determined. A range in which Beer’s law is valid is determined. Study of the complex with 8-hydroxyquinoline (Ox), diphenylguanidine (DPG) and ethylenediamine (ED) present showed that under the effect of these compounds, the optical density of the complex solutions significantly increases and the pH value of the medium providing optimal complexing shifts to the acidic region: pH 2 – 3. The maxima of the absorption of mixed-ligand complexes are observed at λ = 564 nm (CuR 2 -Ox), λ = 568 nm (CuR 2 -DFG), λ = 576 nm (CuR 2 -Ed). Comparison of the values of the stability constants of homo- and mixed-ligand Cu (II) complexes shows that CuR 2 -ED is more stable than the other ones under study. The effect of foreign ions and masking substances on complexation was studied. The selectivity of the obtained reagent for copper (II) determination, compared to the reagents of the same duty known from the literature appeared advantageous. The high selectivity of the studied reactions provided developing of a rapid method for copper determination in rocks. A procedure for the spectrophotometric determination of copper (II) in pyrite is developed.

Reagents were synthesized on the basis of acetyl acetone which consist of –C =Nand –N=Ngroup. Extraction possibilities of some metals with synthesized reagents were studied. It was found that all reagents with respect to the studied elements behave similarly. Based on the extraction abilities elements can be positioned in a row of iron> copper> Ni> Co> zinc>Mn> cadmium. In all cases, the best element to be extracted is iron.

Novel compounds 2-(2-(2-hydroxy-4-nitrophenyl) hydrazono)-1,3-diphenyl propane-1,3-dione and 2-(2-(2-hydroxy-4-nitrophenyl) hydrazono)-1-phenyl butane-1,3-dione are prepared on the base of β-diketones. Crystal and molecular structures of synthesized compounds are determined by X-ray diffraction analysis. The crystals are found to be monoclinic. The compounds are represented only by their hydrazo forms. The structural data for the two obtained compounds are compared with previously reported data.