Compounds In Water Solutions Research Articles

Неоствальдовское поведение дисперсных систем в процессах испарения и кристаллизации капель водно-органических растворов

In this paper, experiments with water-based solutions of some organic compounds, which demonstrate non-Ostwald behavior have been described. Small-volume droplets demonstrate higher stability during evaporation and crystallization in comparison with larger ones, such an effect has been previously described only for water-based solutions of inorganic salts. It has been shown that non-Ostwald behavior has the same thermodynamic nature with Ostwald ripening and could occur in dispersed systems of a complicated chemical composition. Peculiar realization of such phenomena driven by surface activity of organic compounds in water solutions has also been described. The studied regularities could be used to obtain solutions of organic and bioorganic substances with concentrations significantly higher than their solubility limits under normal conditions as well as to reproduce narrow size distributions of droplets in various spray technologies.

Spectral determination of novel methacryloyl guanidine compounds in water solutions

For production and application of novel biocidal guanidine polymer compounds techniques for monitoring the toxic monomer and oligomer components in polymer aqueous solutions are required. A direct spectroscopic method is offered for determination of methacryloyl guanidine salts, polymer and copolymer in water solutions at native pH. The impact of unsubstituted guanidine and methacrylate guanidine contaminants is also discussed. The spectroscopic method offered is simple, rapid and effective for monitoring contamination of polymethacryloylguanidines with toxic monomer components during synthesis of polymers and copolymers from different monomer salts, during dialysis and other manufacturing stages of biocidal polymers.

A Simple and Low-Cost Optical Fiber Intensity-Based Configuration for Perfluorinated Compounds in Water Solution.

We present a very simple approach for the detection of the Perfluorinated Alkylated Substances (PFAs) in water solution. Perfluorooctanesulfonate (PFOS) and Perfluorooctanoate (PFOA) are the most extensively investigated perfluoroalkyl and polyfluoroalkyl substances in water because human exposition can occur through different pathways, even if the dietary intake seems to be their main route of exposure. The developed sensor is based on a specific Molecularly Imprinted Polymer (MIP) receptor deposited on a simple D-shaped Plastic Optical Fiber (POF) platform. This novel chemical sensor has been characterized using a very simple and low-cost experimental setup based on an LED and two photodetectors. This optical sensor system is an alternative method to monitor the presence of contaminants with an MIP receptor, instead of a surface plasmon resonance (SPR) sensor in D-shaped POFs. For the sake of comparison, the results obtained exploiting the same MIP for PFAs on a classic SPR-POF sensor have been reported. The experimental results have shown that the actual limit of detection of this new configuration was about 0.5 ppb. It is similar to the one obtained by the configuration based on an SPR-POF with the same MIP receptor.

Ruthenium Arene Complexes with α‐Aminoacidato Ligands: New Insights into Transfer Hydrogenation Reactions and Cytotoxic Behaviour

The RuII arene complexes [Ru(η6‐p‐cymene)(κ2N,O‐aa)Cl] (aa = l‐glutaminato, 1; l‐homoserinato, 2; l‐tyrosinato, 3; l‐serinato, 4; l‐prolinato, 5; trans‐4‐hydroxyl‐l‐prolinato, 6; l‐threoninato, 7; glycinato, 8) were synthesized in high yields by the reactions of [Ru(η6‐p‐cymene)Cl2]2 with aa/MOH (M = Na, K). The salt [Ru(η6‐p‐cymene)(κ2N,O‐l‐serinato)(PPh3)][CF3SO3], 9[CF3SO3], was prepared in 68 % yield from 4 and AgSO3CF3/PPh3. All the products were fully characterized by analytical and spectroscopic methods, moreover the X‐ray structures of 1 and 2 were elucidated by X‐ray diffraction. Compounds 1–7 and 9[CF3SO3] were studied as catalytic precursors for the transfer hydrogenation reaction (THR) of acetophenone, using 2‐propanol or sodium formate (in water) as hydrogen sources, under variable experimental conditions. The catalytic process was investigated also under microwave irradiation. In general, all the catalytic reactions selectively afforded 1‐phenylethanol, and the best results were achieved with 5 and 6, in terms of both activity and enantioselectivity (enantiomeric excess up to 78 %). The in vitro cytotoxicity of 1, 4, 5 and 9[CF3SO3] was assessed towards the human pancreatic cancer cell line BxPC3 and the mouse embryo fibroblast Balb/3T3 Clone A31 cell line, all of the investigated compounds showing to be substantially inactive. The catalytic and biological results will be discussed in relation to the relevant chemical behaviour of the compounds in water solution.

Analysis of prospects to obtaining nanosized metal compounds by treatment of the water solution by contact non-equilibrium plasma

This paper discusses the prospects of using the method of processing solutions by the contact non-equilibrium plasma with reduced pressure to obtain nanosized metal compounds as highly dispersed powders and colloidal dispersions on example of obtaining oxygen-containing compounds of cobalt, copper and silver compounds in water solution. The difference of this method is the ability to use very dilute solutions, also thanks to its constructive design, the process of synthesis of particles is controlled by adjusting the parameters of plasma-chemical process. It is noted that this method has undoubted advantages in terms of versatility, low power, the possibility of obtaining a size of 10-100 nm particles. A separation into fractions by separating them in the water solution after the plasma chemical treatment is possible. The ability to control the process of synthesis of particles by adjusting the parameters of plasma chemical processing, ease of control parameters of the process, possibility of obtaining particles with the division on fractions, possibility of a significant reduction in energy consumption and improve product quality in the transition to film mode allows to speak about high prospects of this method to produce ultra and nanosized metal compounds.

CYTOGENETIC EVALUATION OF THE DRINKING WATER TOXICITY

There was considered the use of biotesting for the assessment of the quality of drinking water from the different water supply sources (artesian, packaged and water-pipe one). The method consists in determination of the toxicants action on the specially selected organisms in the standard conditions with registration of changes at behavior, physiological, cellular and subcellular level using hematological indices of fish, frogs, rats and the lymphocyte cultures of the peripheral human blood. Physical-chemical methods determine only the presence and number of chemical elements in the tested water samples because of the very large number of possible combinations of chemical compounds in water solutions (more than 75 million combinations), including behavior of anthropogenic compounds and the natural vulnerability of the water ecosystems to the combined effects from its toxic influence. As the optimal set of determination of the some structural and functional changes of cell genome as the result of the toxic influence of combination of the chemical compounds in the water solutions was offered the micronuclear test and leukocytic formula of the fish, frog and rat blood as biomarker. The reaction of fish, frog, rat test-organisms on the toxic irritation is presented in the change of qualitative content of the cells of peripheral blood. There were demonstrated the prospects of the use of hematological indices of the following test-organisms: Danio rerio fishes, Xenopus clawed frogs, Wistar rats and also the lymphocytes cultures of the human peripheral blood. The special attention was paid to the assessment of the risk for human health of the toxic substances in drinking water, genotoxicity and cytotoxicity that are revealed using hematological indices of animal cells. The universality of cellular organization opens the wide possibilities for toxicological studies using peripheral blood of the different groups of animals (fish, frogs, rats), human lymphocyte cultures and allow assume the following possibility of extrapolation of the received results on human organism

The Effect of Support on the Surface Properties and Photocatalytic Activity of Supported TiO<sub>2</sub> Catalysts

In the present work two series of TiO2/SiO2 and TiO2/Al2O3 photocatalysts were investigated. The content of the active component was varied. Photocatalysts were prepared using the heterogeneous deposition method. It was revealed that the prepared photomaterials demonstrate high photocatalytic activity in decomposition of organic compounds in water solutions, and application of SiO2 aerogel as a support ensured the incorporation of TiO2 into the structure of the support via formation of Ti-O-Si bonds. The prepared materials, in which the active component is under the influence of electron-acceptor media, demonstrated enhanced selectivity of the surface towards the ability to generate electronic vacancies (about 90%). According to the experimental data, TiO2/SiO2 photocatalysts proved to be more active in comparison with TiO2/Al2O3 materials.

How do complexities form?

Science knows many examples when ideas that appeared naive and interesting only to historians were read anew and became topical in light of previously unknown facts. More than 2500 years ago, the Ancient Greek philosopher Thales, in search of arche, the element underlying the existence of all substances, generalized his knowledge about the surrounding world and concluded that “water stood under all things.” Today we know that matter has a highly complicated composition and water is a compound that appeared at a late stage of the development of the universe, but the thesis of Thales acquires a new meaning in considering the evolution of matter on our planet. A.I. Oparin wrote about the important role of water in the rise of organic matter, but the author of the article published below goes further and shows that data of geology, geochemistry, geophysics, and other related disciplines make it possible to conclude that water is the key element of the matter-complicating mechanism, and, hence, studying the properties of water and water environments deepens our understanding of global evolution and, most importantly, favors the construction of an evolutionary model in which different stages do not oppose one another rigidly but are described as the components, although fundamentally different, of the continuous and consistent process of emergence of complex compounds in water solutions of various compositions.

Solvent impact on the aromaticity of benzene analogues: implicit versus explicit solvent approach

Solvent impact on the structural index of aromaticity was modelled by polarised continuum field approximation (IEFPCM) and hybrid quantum chemistry (QM/MM) method. Significant solvent related relaxation of the solutes geometries were noticed especially for highly polar species. The significant reduction of the aromaticity was observed for some aromatic compounds in water solution compared to gas phase. The rationale of this fact was provided based on dipole moment changes, energy penalty for polarisation of solute and the distribution of frontier orbital densities. The incoherent predictions of explicit and implicit solvation models are noticed since in some cases the PCM approach artificially exaggerate the geometry relaxation in solution which is not observed if explicit solvent molecules are taken into account.

新規水溶性チタン錯体を用いた水熱法による酸化チタン多形の選択的合成

A panel of new stable and water soluble complexes of titanium (IV) with natural hydroxy-carboxylic acids such as citric, tartaric, lactic or glycolic acid as ligands was developed. A typical structure of these complex ions includes a peroxo-group, and a hydroxy-carboxylic acid molecule attached to the metal ion by carboxylic and hydroxylic groups to form stable species. The tight coordination and negative charge of complex ions are responsible for stability of these new compounds in water solutions in a wide range of temperatures and pH. Use of natural non-toxic ligands and ammonium as counterions make such titanium compounds convenient reagents for green synthesis of titanium containing materials by aqueous solution methods.The architecture of titanium complexes includes structural motifs of different polymorphic forms of TiO2, which allows for application of these compounds as building blocks (tecton) for synthesis of titania with different crystal structures by a simple hydrothermal processes. In this way anatase, rutile, TiO2(B) and brookite were prepared in a reproducible and highly selective way. For the first time TiO2(B) and brookite were synthesized as single phase nano-crystals by a one-pot hydrothermal process, and their outstanding photo-catalytic activities were revealed.

Tris(2-cyanoethyl)tin(IV) bromide and tris(2-cyanoethyl)tin(IV) iodide, their structure, properties and reactions with adenosine, AMP and ATP

Complexes [Sn(CH 2CH 2CN) 3I] ( 1) and [SnBr(CH 2CH 2CN) 3] ( 2) have been obtained by the oxidation reactions of hexakis(2-cyanoethyl)ditin(III) by means of iodine and bromine. The complexes have been characterized by NMR and IR spectroscopy methods and X-ray crystallography. Both compounds consist of zigzag single-strand chains with a bridging 2-cyanoethyl ligand coordinating via the CH 2 group and N atom. The tin atoms are in a distorted trigonal bipyramidal environment with bromo or iodo ligands and a nitrogen atom occupying the axial coordination sites. The Sn(1)–N(3i) distances in complexes 1 and 2 are considerably longer than the tin-equatorial ligand bonds. The molecular and electronic structures and IR spectra of [SnBr(CH 2CH 2CN) 3] mononuclear and [SnBr(CH 2CH 2CN) 3] 2 dinuclear fragments of the complex have been studied by the DFT B3LYP method. The calculated interatomic distances for the entity containing a five-coordinate tin atom agree well with those found crystallographically. The compounds in water solutions form trigonal bipyramidal complexes containing aqua and hydroxo axial ligands. The interaction of these complexes with adenosine, 5′-adenosine monophosphate and 5′-adenosine triphosphate has been investigated.

TiO2-based photocatalysts impregnated with metallo-porphyrins employed for degradation of 4-nitrophenol in aqueous solutions: role of metal and macrocycle

Photodegradation of organic compounds in water solutions by means of economically advantageous and environment-friendly processes is a topic of growing interest. In recent years a great attention has been devoted to TiO2-based photocatalysts for the oxidative degradation of various organic pollutants. In this context, we have prepared new photo-catalytic polycrystalline TiO2 systems impregnated with sensitizers, i.e., copper, iron or manganese porphyrins, and investigated their photoactivity for 4-nitrophenol oxidation compared with that of bare TiO2. A significant improvement of the photoreactivity was observed in the case of TiO2 impregnated with copper porphyrin, while only a slight beneficial effect was observed in the case of iron porphyrin. In contrast, the presence of manganese porphyrin appeared to be detrimental.

Development of enzyme biosensor based on pH-sensitive field-effect transistors for detection of phenolic compounds

This article describes a biosensor based on pH-sensitive field-effect transistors (pH-FETs) as transducer, and immobilised enzyme tyrosinase as biorecognition element, which was used for the determination of phenolic compounds in water solutions. The biologically active membrane was formed by cross-linking of tyrosinase with bovine serum albumin (BSA) in saturated glutaraldehyde (GA) vapours on the sensitive transducer surface. The main analytical characteristics were studied under different conditions as well as the possibility to optimise these working parameters. Different factors such as the pH of immobilisation, the enzyme loading, the time of exposition to glutaraldehyde vapours were investigated in regards to the influence on sensitivity, limit of detection, dynamic range, and operational and storage stability.

Sonochemical and photochemical oxidation of organic matter

Recent developments in sonochemistry have led us to study its use to treat water and wastewater. The effects of ultrasound wave in hydrophilic chemical oxidations are mainly due to hydroxyl radical production during the cavitation-induced water decomposition. Currently, the sonochemical destruction of aromatic compounds in water solution is obtained with low rates. The aim of this work is to evaluate the efficiency of the sonochemical effect in conjunction with a photochemical irradiation. Taking phenol as an example, the combined action of sonochemistry and photochemistry has been considered in a ‘sonuv’ reactor. An important enhancement of the degradation rate of phenol has been observed. It may be the result of three different oxidative processes: direct photochemical action, high frequency sonochemistry and reaction with ozone (produced by UV irradiation of air). The process has been successfully tested to lower the chemical oxygen demand of a municipal wastewater.

Modeling Infinite Dilution Activity Coefficients of Environmental Pollutants in Water Using Conformal Solution Theory

Abstract The fate of organic pollutants in the environment and in wastewater treatment processes is commonly modeled using a Henry's law constant approach. By definition, Henry's law constant is the product of a compound's vapor pressure and infinite dilution activity coefficient. For many organic compounds in water solution, the infinite dilution activity coefficients are very large and are not adequately modeled by conventional methods such as UNIFAC. In this work, infinite dilution activity coefficients were determined for phenol, pyridine, aniline, p-toluidine, and o-toluidine in water by differential ebulliometry. An equation rigorously derived from conformal solution theory and van der Waals one-fluid mixing rules was used to model the temperature dependency of the infinite dilution activity coefficients. No corrections other than the introduction of two adjustable parameters were incorporated into the model to account for the strong interactions between molecules. Relationships derived from corresponding states theory were used to relate molecular parameters for size and energy interaction to the critical properties. Arithmetic mean combining rules and geometric mean combining rules were used to calculate size and interaction parameters, respectively.

Syntheses and Antibacterial Activity of New N-Halamine Compounds

The syntheses of three new N,N′-dihalamine compounds in the class of tetramethylimidazolidinones are described. The stabilities and disinfection efficacies against Staphylococcus aureus of the compounds in water solution are compared with those for 3-chloro-4,4-dimethyl-2-oxazolidinone which has been studied extensively in recent years in these laboratories and elsewhere. The new compounds exhibit considerable promise as general-purpose disinfectants, particularly in applications for which long-term stability is necessary.

ChemInform Abstract: Chelation of Metal Anions with Organic Hydroxy Compounds in Water Solutions

Chemischer InformationsdienstVolume 17, Issue 43 Reviews ChemInform Abstract: Chelation of Metal Anions with Organic Hydroxy Compounds in Water Solutions M. BARTUSEK, M. BARTUSEKSearch for more papers by this author M. BARTUSEK, M. BARTUSEKSearch for more papers by this author First published: October 28, 1986 https://doi.org/10.1002/chin.198643335Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue43October 28, 1986 RelatedInformation

X-ray structure of the ternary complex Zn(II)-ATP-2,2'-bipyridyl and possible model for ATP transport.

Ternary complexes between metal ions, nucleotides and aromatic heterocyclic amines are being investigated by X-ray diffraction as possible models for enzyme-metal-substrate interactions. Kennard and coworkers have reported the crystal structure of the ATP disodium salt. Although more recently several crystal structures of binary and ternary complexes between metal ions and nucleoside monophosphates have been reported, no structure combining metal complexes with nucleoside di- or triphosphates has been reported. Most divalent metal ions catalyse the nonenzymatic transfer of phosphate from nucleoside polyphosphates to various acceptors. Therefore, these compounds in water solution undergo extensive hydrolysis in the presence of metal ions, leading to the formation of the monophosphates; for instance, at pH 6.5, Cu2+ accelerates the hydrolysis of ATP by a factor of about 300 (ref. 5). We report here the crystal and molecular structure of the complex [Zn(II)-H2ATP-2,2'-bipyridyl]2.4H2O, determined by single crystal X-ray analysis. The complex molecule provides a possible model for ATP transport and phosphate group transfer mechanism.

An Improved Method of Determining Concentration of Quaternary Ammonium Compounds in Water Solutions and in Milk

abstract Methods of determining concentration of quaternary ammonium compounds (QACs) in water solution and in milk have been reviewed briefly by Miller and Elliker, who also reported a new, rapid test for QAC in milk based on reaction of QAC with eosin to form a red precipitate and subsequent titration to a colorless endpoint with a standard solution of anionic surf ace active agent (2). The rapid test has proven satisfactory for routine detection of QAC in milk, but the extraction method used does not yield total recoveries of QAC. Consequently a series of known concentrations of QAC in milk must be set up as standards and tested with the unknown sample for accurate interpretation of results with the method. A study therefore was undertaken to improve methods of extraction and titration of QAC in milk. The results obtained in this study also have been applied in developing a new method of determination of QAC in water solutions.