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The reaction of sulfoxides with peroxy acids in various organic media was studied. The reaction mechanism involves the rapid formation of a sulfoxide-–peroxy acid intermediate which decomposes in the second stage to form carboxylic acid and the corresponding sulfone. The second stage is the rate-limiting step. The reaction medium significantly affects the rate of oxidation. The calculated activation parameters of the oxidation process indicate a compensation effect in the investigated reaction. Correlations between the main physicochemical parameters of solvents and the effective rate constants (k) of dimethyl sulfoxide oxidation with peroxy acids were found. Depending on the reaction conditions, the main factors affecting the k values are specific and nonspecific solvation of the reactants and structural factors. [ABSTRACT FROM AUTHOR]

Four complexes [Ni(DMA)2(H2O)4]Cl2·2H2O, [Ni(DMF)2(H2O)4]Cl2·2H2O, and [Ni(DMA)6][NiCl4], [Ni(DMF)2(H2O)2Cl2] were isolated from ternary water-organic saline systems containing nickel chloride and N, N-dimethylacetamide-water and N, N-dimethylformamide-water binary solvents. The obtained complexes were studied by X-ray structural analysis. The formation of hydrogen bonds between water molecules of the nickel ion solvate sphere, chloride ions, and non-coordinated water molecules located in the cavity of the crystal structure was detected. [ABSTRACT FROM AUTHOR]

The possibility of using spectrophotometric method for the evaluation of ozone solubility in highly concentrated solutions by measuring absorption in the Chappuis band directly in the liquid phase has been demonstrated. The solubilities of ozone in various organic solvents have been determined, and its limiting solubility has been calculated. The molar absorption coefficient in the long-wavelength band of ozone has been found to depend on the solvent nature. [ABSTRACT FROM AUTHOR]

In this work, a new application of Cu(II) complex with 3-hydroxy-2-naphtoic acid (Cu-HNA) as a reusable heterogeneous catalyst in the synthesis of tetrahydrobenzo[a]xanthene-11-ones via a one-pot three-component condensation of aryl aldehydes, 2-naphthol, and dimedone in solvent-free condition was reported. At the end of the reaction, with a simple filtration, the catalyst was easily recovered and reused at least five times with no significant loss of its catalytic activity. Appropriate activity and efficient of the catalyst, very good yields, short reaction time, mild and simple work-up, and no use of organic solvents are other benefits of this proposed methodology. [ABSTRACT FROM AUTHOR]

Layered magnesium silicate was modified by water-insoluble chlorin e6 derivatives with two and three ethanolamine fragments on the periphery of the macrocycle by introducing chlorin e6 derivatives into the reaction medium as solutions in hydrochloric acid without the use of organic solvents. The modified layered silicates obtained are characterized by intense fluorescence along with photostability and exhibit photochemical activity in reactions of photosensitized oxidation of model pollutants like xanthene (rhodamine 6G) and azo dyes (methyl orange). [ABSTRACT FROM AUTHOR]

The metal-exchange reaction between Cd(II) octa-(4-bromophenyl)porphyrinate and cobalt chloride in DMF and DMSO was studied by UV-Vis spectroscopy. The kinetic parameters of the metal-exchange reaction were calculated. A possible mechanism of the reaction was established. An effect of the nature of the solvent and metal salt on the reaction rate was revealed. Comparative analysis of the apparent rate constants of the metal exchange reaction between CoCl2 and Cd(II) octa-(4-bromophenyl)porphyrinates and Cd(II) octa-(4-bromophenyl)tetraazaporphyrinate in DMF and DMSO was performed. [ABSTRACT FROM AUTHOR]

The extraction of trace amounts of U(VI), Th(IV), Am(III), and lanthanides(III) from nitric acid solutions with polyphosphinylbenzenes was studied. The stoichiometry of the extracted complexes was determined, and the influence of the extractant structure, the HNO3 concentration in the aqueous phase, and the nature of organic solvents on the efficiency of metal ions extraction into the organic phase was considered. It was found that compounds with diphenylphosphoryl groups attached directly to the benzene ring in the ortho position in their molecules have the highest extraction ability with respect to actinides and lanthanides. [ABSTRACT FROM AUTHOR]

Isocyanates readily reacts with NaN3 in the presence of ZnCl2 in organic solvents to form the corresponding carbamoyl azides. The formation of carbamoyl azides completed in 5–10 min at room temperature, which prevent the risk of release of hydrogen azide. The obtained carbamoyl azides without isolation can be used for the preparation of 1-substituted tetrazol-5-ones. [ABSTRACT FROM AUTHOR]

The reactions of 1-germatranol hydrate with malonic, succinic, maleic, cork, sebacic acids, and bistrimethylsilyl ester of succinic acid, and also of bis(germatran-1-yl)oxane with succinic acid in acetonitrile, water, methanol, and dimethylsulfoxide were studied. In organic solvents, mono- and dicarboxyl-substituted 1-germatranols are formed, which, like 1-germatranol, are reversibly hydrolyzed with water in an acidic medium. Removing water from reaction mixtures due to evaporation and a topochemical reaction increases the yield of esterified 1-germatranol. [ABSTRACT FROM AUTHOR]

Extraction of rare-earth elements(III) ions from chloride solutions with mixtures of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and phosphoryl-containing podands in organic solvents has been studied. The observed significant synergistic effect is associated with the formation of hydrophobic mixed-ligand complexes of rare-earth elements(III). The stoichiometry of the extracted complexes has been determined, and the extraction constants have been calculated. The influence of the phosphoryl-containing podand structure, the organic solvent nature, and the aqueous phase composition on the efficiency of the extraction of rare-earth element(III) ions into the organic phase has been considered. [ABSTRACT FROM AUTHOR]

Extraction of rare earths(III) from hydrochloric acid solutions with mixtures of new tridentate carbamoylmethylphosphine oxides Ph2P(O)CH2CON(R)CH2CH2P(O)Ph2 (R = Me, Bu, Oct) and 4-benzoyl-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one in organic solvents has been studied. The observed strong synergistic effect has been attributed to the formation of hydrophobic mixed-ligand rare earth complexes in the organic phase. Stoichiometry of the extractable complexes has been determined, and extraction constants have been calculated. The effect of organic solvent and composition of the aqueous phase on the extraction efficiency has been analyzed. [ABSTRACT FROM AUTHOR]

The association of N-[3-(dimethylamino)propyl](meth)acrylamides in tetrachloromethane, tetrahydrofuran, and N, N-dimethylformamide has been studied by means of IR spectroscopy and quantum-chemical simulation at the B3LYP/6-31+G(d,p)/PCM level. The effect of the hydrogen bonding capacity of the solvent on the degree of participation of N-[3-(dimethylamino)propyl](meth)acrylamides in hydrogen bonding with the formation of the amide-solvent type self-associates and heteroassociates has been elucidated. [ABSTRACT FROM AUTHOR]

Exploration (factor, cluster, and decision tree), regression (multiple linear regression), and neural network (regression, classification) models of clustering, approximation and prediction of the stability constants of cation complexes with ionophore antibiotics (nonactin, monactin, dinactin, trinactin, ennatin B, monensin A, and valinomycin) according to the properties of organic solvents (methanol, ethanol, acetonitrile, and nitrobenzene) and cations (Li+, Na+, K+, Rb+, Cs+, Tl+, Ag+, NH4+, Mg2+, Ca2+, Sr2+, Ba2+, and Mn2+) have been developed. It has been shown that neural network performance is better than that of multiple linear regression (the correlation coefficient on the training sample 0.756 compared to 0.697). The neural network classifier and the classification tree has confirmed the clustering of stability of ionophore–cation complexes carried out by the exploratory k-means method by 97.2%. The prognostic capabilities of the constructed multilayer perceptron have been demonstrated. [ABSTRACT FROM AUTHOR]

It was proved by the IR spectroscopy that the first coordination sphere of nickel cations in the NiCl·2DMSO·9HO, NiCl·5DMSO·4HO, and NiCl·4DMSO·2HO compounds contains dimethyl sulfoxide and water ligands. According to X-ray structural analysis, in crystals of the NiCl·4DMSO·2HO compound, noncovalent contacts between sulfur atoms of neighboring dimethyl sulfoxide molecules are realized in the inner sphere of the complex. [ABSTRACT FROM AUTHOR]

On the way to solving the problem of developing an ecofriendly technology for preparing hydrophobic protective coatings to replace the existing technology involving casting from polymer solutions in toxic organic solvents, amphiphilic organosilicon oligomers, promising emulsifiers for preparing aqueous emulsions of organosilicon polymers, were synthesized. The synthesized oligomers were used to obtain stable aqueous emulsions of a film-forming silicone block copolymer. The resulting emulsions can be used to form hydrophobic protective coatings on the surface of construction materials. It was shown that the contact angle of wetting depends on the specific features of the preparation of the emulsion and reaches a maximum of 134°. [ABSTRACT FROM AUTHOR]

Models of multiple linear regression and multilayer artificial neural network have been developed for modeling and predicting the stability constants of sodium and potassium coronates basing on the properties of aqueous-organic solvents (water-methanol, water-propan-2-ol, water-acetonitrile, and water-acetone). The values of the coronates stability constants in water-ethanol solvents have been predicted, and the predictions of the models of multiple linear regression and an artificial neural network models have been compared. The contributions of electrostatic, cohesive, and electron-donating interactions to the increase in the stability of the coronates have been quantitatively assessed basing on the models of multiple linear regression and the principle of free energies linearity. Neural network models based on unsupervised (multilayer perceptrons) and supervised (Kohonen networks) learning algorithms have been developed to classify the stability of sodium and potassium coronates. The neural network classifiers have fully confirmed the classification of the coronated stability via the k-means exploration method. [ABSTRACT FROM AUTHOR]

О′,О′-Diethyl-[2-(3,4-dicyanophenoxy)phenyl]phosphonate has been synthesized for the first time and introduced in template condensation on lithium and zinc cations to prepare a series of new neutral and acidic phthalocyanines containing four fragments of 2-oxyphenylphosphonic acid. A scheme of modification of the peripheral substituents at the phosphoryl group was developed allowing a targeted synthesis of phthalocyanine ligands and complexes soluble in organic solvents or aqueous media. [ABSTRACT FROM AUTHOR]

Choline tetrachloroferrate with a magnetic response property is applied in multicomponent one-pot synthesis of 2-amino-4 H-chromenes as effective catalyst. The catalyst is characterized by the UV-Vis and Raman spectroscopies and by the electrospray ionization mass spectrometry. [ABSTRACT FROM AUTHOR]

New metal-containing polymers, poly(salicylidene azomethines) containing metal atoms (Co, Ni, Cu) in the backbone, were synthesized from aromatic carbazolediamine derivatives. It was found that the polymers with a decyl substituent in the carbazole fragment are soluble in organic solvents (chloroform, methanol, DMSO, DMF) and exhibit film-forming and semiconductor properties. IR and NMR spectroscopy was used to show that the semiconductor properties of the new polymers are associated with the presence in the polymer backbone of transannular polyconjugation zones formed by intramolecular donor-acceptor interactions of the metal and nitrogen valence shells. [ABSTRACT FROM AUTHOR]

Phthalocyanines containing gallic acid moieties were synthesized and investigated by the method of electron absorption spectroscopy. It was shown that in organic solvents the prepared phthalocyanines exist predominantly in associated form. [ABSTRACT FROM AUTHOR]

4,5-bis[(4-phenoxy)phenoxy]phthalonitrile was obtained by the reaction of 4,5-dichlorophthalonitrile with 4-phenoxyphenol. On its basis 2,3,9,10,16,17,23,24-octakis-[(4-phenoxy)phenoxy]phthalocyanine and its single- and double-decked complexes with erbium were synthesized. Spectral-luminescent properties of resulting phthalocyanines were studied. The tendency of phthalocyanines to association in dichloromethane depends on the structure of their molecules. [ABSTRACT FROM AUTHOR]

The interaction of a series of acrylic and cinnamic acid amides with bis(pentafluorophenyl)-phosphinic acid proceeds vigorously at room temperature without any catalyst in the presence of the organic solvents providing for a high fraction of the >P-OH tautomer of the phosphinic acid. The reactions have afforded (2-carbamoylethyl)bis(pentafluorophenyl)phosphine oxides in a high yield. [ABSTRACT FROM AUTHOR]

Oxidation of ferrocenylboric acid with hydrogen peroxide in organic solvents and in aqueous solutions in the presence and in the absence of acids and bases has been investigated by electron absorption spectroscopy. Kinetics of FcB(OH) oxidation in neutral, acidic, and basic media has been studied; possible mechanisms of the reactions accounting for the substituent acting as the Lewis-type acidic center have been suggested. [ABSTRACT FROM AUTHOR]

In this article, the first use of silicotungstic acid (HSiWO) as a catalyst for the synthesis of octahydroxanthene-1,8-diones by the reaction of 5,5-dimethylcyclohexane-1,3-dione (dimedone) with various aldehydes under thermal solvent-free conditions is described. The obtained results showed that the catalyst has a high catalytic activity, and the desired products were obtained in high yields. Moreover, the catalyst was found to be reusable, and a considerable catalytic activity still could be achieved after the fifth run. Easy work-up and avoidance of using harmful organic solvents are the other advantages of this simple procedure. [ABSTRACT FROM AUTHOR]

The organic bismuth compounds PhBi(OCCH=CHCH) and PhBi(OCEt) decompose under scattered light in the presence of spin traps (2-methyl-2-nitrosopropane and C-phenyl- N- tert-butylnitrone) in organic solvents (acetonitrile, benzene, toluene) to form adducts of phenyl radicals with the traps. [ABSTRACT FROM AUTHOR]

Isocyanates readily reacts with NaN3 in the presence of ZnCl2 in organic solvents to form the corresponding carbamoyl azides. The formation of carbamoyl azides completed in 5–10 min at room temperature, which prevent the risk of release of hydrogen azide. The obtained carbamoyl azides without isolation can be used for the preparation of 1-substituted tetrazol-5-ones. [ABSTRACT FROM AUTHOR]

Modified extractants, carbamoylmethylphosphine oxides Ph2P(O)CH2CON(R)CH2P(O)Ph2 (R = Et, i-Pr, Bu, Oct), containing a phosphoryl group in the amide part of the molecule, have been synthesized. The extraction of microquantities of REE(III), U(VI), and Th(IV) with solutions of the obtained extractants in organic solvents from nitric acid solutions has been studied. The stoichiometry of the extractable complexes was determined, and the influence of the extractant structure, the organic diluent nature, and the aqueous phase composition on the efficiency and selectivity of the U(VI), Th(IV), and REE(III) extraction into the organic phase was considered. It has been shown that the modification of diphenyl(N,N-dialkylcarbamoylmethyl)phosphine oxide by introducing an additional coordinating group CH2P(O)Ph2 into the amide part of the molecule leads to an increase in the efficiency of heavy REE(III) extraction and a decrease in the efficiency of light REE(III), and also Th(IV) and U(VI) extraction from nitric acid solutions. The degree of REE(III), U(VI), and Th(IV) extraction into the organic phase by the carbamoylmethylphosphine oxides increases significantly in the presence of the ionic liquid 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide. [ABSTRACT FROM AUTHOR]

α-Conjugated oligoselenophenes are characterized by very low solubility in organic solvents. Their higher solubility may be achieved by introducing alkyl side chains into the β-positions of selenophene moieties. For the first time, β,β′-dihexyl sexiselenophene is synthesized according to the conventional approach. Physical and electrochemical studies of β,β′-dialkyl oligomers are analyzed and compared with corresponding thienyl oligomers. [ABSTRACT FROM AUTHOR]

By the reaction of nucleophilic substitution of bromine atom and the nitro group of 4-bromo-5- nitrophthalonitrile 4,5-diphenoxyphthalonitrile was obtained and on its basis new derivatives of octa-4,5- phenoxyphthalocyanine were synthesized soluble in water- and organic solvents. The spectral properties and thermodestruction of the products were investigated. [ABSTRACT FROM AUTHOR]

Computer analysis of the thermodynamic constants of complexation of [2.2.2]-cryptand with alkali metal cations (M[222]+ cryptates with M = Li, Na, K, Rb, and Cs) in water and organic solvents such as methanol, ethanol, 1-propanol, acetonitrile, benzonitrile, acetone, N,N-dimethylformamide, N-methylpyrrolidone, nitrobenzene, nitromethane, 1,2-dichloroethane, and propylene carbonate at 298.15 K has been performed. Exploratory (factorial, cluster, discriminant, canonical, decision tree), regression and neural network models of effects of the properties of solvents and cations on the cation cryptates stability have been built. The neural network approximator MLP 4-7-1 and the classifiers of the stability constants of cryptates – the multilayer perceptron MLP 4-7-4 and the self-organizing Kohonen map SOFM 8-4 – have been trained. Independent data on the stability constants of alkali metal cations cryptates demonstrate the predictive capabilities of the trained MLP 4-7-1 perceptron approximator. [ABSTRACT FROM AUTHOR]

Exploratory, regression, and neural network analysis of the stability constants of crown ether [12C4, 16C5, (CH3)216C5, DB21C7, DB24C8, DCH24C8, DB30C10] 1 : 1 complexes with alkaline (Li+, Na+, K+, Cs+, Rb+), alkaline-earth (Ca2+, Sr2+, Ba2+), and heavy (Ag+, Tl+, Co2+, Cu2+, Pb2+) metals and NH4+ in water and organic solvents (methanol, acetonitrile, acetone, N,N-dimethylformamide, nitrobenzene, nitromethane, 1,2-dichloroethane, propylene carbonate) at 298.15 K obtained via conductometry has been performed. Factor, cluster, discriminant, canonical, decision tree, regression, and neural network models of clustering, approximation, and prediction of thermodynamic constants of the complexation depending on the properties of the ligand, the cation, and the solvent have been developed. The trained MLP 7-5-5 Multilayer Perceptron Cluster has completely confirmed the k-means clustering. Independent data on the stability constants of coronates have demonstrated the predictive capacity of the trained perceptron-approximator MLP 7-7-1. [ABSTRACT FROM AUTHOR]

The results of the study of ternary systems containing copper, cobalt, nickel, and cadmium halides and sulfates in binary water-organic and mixed organic solvents are summarized. The influence of the donor-acceptor properties of the ternary system components, the relative dielectric permittivity, and the intermolecular association in the mixed solvent on the solubility of salts and the crystalline structure of solvates is analyzed. [ABSTRACT FROM AUTHOR]

The data on the kinetics of the reaction between hexachlorocyclotriphosphazatriene (the phosphazene) with pyridine N-oxide in mixed organic solvents in the presence of water are presented. The reaction of the phosphazene with pyridine N-oxide leads to the formation of the onium salt. It has been found that water catalyzes this reaction, the catalytic action resulting from the solvation of the polar transition state due to the formation of the phosphazene complex with hydrogen bonding, thus facilitating the rupture of the phosphorus bond with the leaving anion. [ABSTRACT FROM AUTHOR]

The kinetics of thermal decomposition of didecanoyl diperoxyadipate in different organic solvents have been studied. The primary homolytic dissociation of the peroxide bond (O-O) is accompanied by secondary induced chain decomposition processes. The reaction medium affects both the rate of primary homolytic decomposition and secondary decomposition processes. Correlation equations have been proposed for the rate constants of the reactions under study and physicochemical parameters of the solvents. [ABSTRACT FROM AUTHOR]

Solubility of copper(II) chloride at 25°C in binary organic solvents consisting of dimethyl sulfoxide, N,N-dimethylacetamide, and 1,4-dioxane was determined by the isothermal saturation method. The shape of solubility isotherms for all ternary systems under study is connected with the structural type of formed copper chloride solvates, the composition of which is defined by the solvent donor number. Solvates crystallize predominantly, where the metal ion coordinates molecules of the solvent with a greater donor power. The temperature increase in the system CuCl2-dimethylacetamide-dioxane up to 50°C leads to the formation of the cluster compound [Cu4Cl6O(DMA)4]; its structure was determined by the X-ray structural analysis method. [ABSTRACT FROM AUTHOR]

Acetic acid functionalized poly(4-vinylpyridinium) bromide is a highly efficient and recyclable catalyst for the construction of 2,4,5-trisubstituted imidazole derivatives by a three-component condensation of benzyl with various aldehydes and ammonium acetate under solvent free conditions. The microwave initiated process leads to analytically pure compounds within 2-5 min. The advantages of this “green” methodology are cost-effectiveness, simple procedure, low energy consumption, no involvement of organic solvents, safe operation, clean reaction profile, high yields, and recyclability of the catalyst. [ABSTRACT FROM AUTHOR]

Thermal decomposition of peroxydecanoic acid has been investigated in various organic solvents. The reaction medium significantly affects the rate of peroxydecanoic acid thermal decomposition. It has been shown that primary homolytic decomposition of peroxy group is followed by induced radical chain decomposition reactions. The solvent nature influences both primary homolytic decomposition and secondary induced reactions. The correlation equations relating kinetic parameters of peroxydecanoic acid thermolysis and basic solvent properties have been derived. [ABSTRACT FROM AUTHOR]

Aldol and cross-aldol condensations of aromatic aldehydes with various ketones in the presence of nanometasilica disulfuric acid (NMSDSA) as heterogeneous catalyst are presented. The catalyst was prepared according to the developed earlier method using inexpensive and readily available starting materials. The highly active catalyst gave excellent yields of the desired aldol products without self-condensation reaction taking place. Reaction times were short, the procedure and work-up were simple, and no volatile or hazardous organic solvents were involved. The catalyst could be recovered three times with only slight reduction in activity. [ABSTRACT FROM AUTHOR]