Search

Background: This study is one of the dynamics molecular docking that presents the interactions between a molecular model of the mixture of humic acid structure and 18 aristolochic acids structures, from PubChem database in a water box that simulates the environment reactions. Objective: The major objective was to identify what happens in this procedure(LD/MM+) with the coupled species. Method: LD/MM+ SIMULATION ( Langevin dynamics simulation) Results: The R-Squared statistic indicates that the model as fitted by MLR , explains 90.9437% of the variability in Volume. Conclusion: The interactions of these acids, the types of forces, and the way that these molecules can get closer to each other, in terms of total energy density, while identifying the specificities vis-à-vis of wateraromaticity or water-reactivity behaviors.

The adsorption properties of two coordination polymers, resulting from the reaction of divalent metal (Ca2+ or Co2+) salts with (2-carboxyethyl)(phenyl)phosphinic acid, are presented in this paper. The structural and textural characterization before and after adsorption experiments is presented. The adsorbent materials were prepared using the hydrothermal procedure. The compound Ca[O2P(CH2CH2COOH)(C6H5)]2 (CaCEPPA) has a layered topology, with the phenyl groups oriented into the interlayer space and crystallizes in the monoclinic system. Compound Co2[(O2P(CH2CH2COO)(C6H5)(H2O)]2·2H2O (CoCEPPA) has a 1D structure composed of zig-zag chains. The adsorption performances of CaCEPPA and CoCEPPA materials were tested in the removal of cadmium and lead from aqueous solutions. The optimum pH of ions adsorption was found to be five for both adsorbent materials. Pseudo-first and second-order kinetic models were used for fitting kinetic experimental data, and Langmuir and Freundlich isotherms were used for modeling the equilibrium experimental data. The pseudo-second-order kinetic model and Langmuir isotherm best described the adsorption of Cd and Pb ions onto the studied materials, judging from the results of the error function (correlation coefficient, sum of square error, chi-square test, and average relative error) analysis. The studied materials present a higher affinity for Cd ions compared with the adsorption capacity developed for the removal of Pb ions from aqueous solutions. CoCEPPA showed the highest adsorption performance in the removal process of metal ions from aqueous solutions compared with CaCEPPA (qm = 54.9 mg Cd2+/g of CoCEPPA, qm = 36.5 mg Cd2+/g of CaCEPPA).

In this paper, copolymerization of methyl methacrylate (MMA) with n-butyl acrylate (BA) in a bubble column reactor using benzoyl peroxide as free radical initiator, at a temperature over 85 °C, is presented. This mode of copolymerization keeps an inert atmosphere throughout the entire reaction and contributes to proper mixing of the monomers. Higher pressure of the bubbling ensures the faster contact of the species, and a higher conversion was obtained in a shorter reaction time. The conversion of monomer at 124 Pa after 210 min is total, which is particularly noteworthy due to the absence of residual monomer that represents hazardous compounds, with negative impact upon employees and end-user safety. Higher conversions are obtained at 96 °C, 124 Pa nitrogen bubble pressure, 60/40% moles monomer ratio BA/MMA and 2% POB. The molar mass Mw, Mn and PDI decrease with the increase in temperature quite linearly. In the absence of nitrogen bubbling, the copolymer composition is approximately the same as in the feeding mixture. The corrosion protection efficiency of steel painted with these acrylic coatings was carried out by means of OCP and potentiodynamic polarization testing and electrochemical impedance spectroscopy (EIS).

The present work describes the synthesis of novel hybrid materials by grafting process of phenyl phosphinic acid on different metal oxide surfaces (V2O5, ZrO2 and SnO2), by using a reactive milling process. Therefore, the syntheses took place in the solid phase, avoiding the presence of solvents. The grafting of the metal oxide surface is performed by using phenyl phosphinic acid as the coupling agent. After the syntheses in the solid phase were finished, the grafted materials were further characterized by FTIR, TGA, SEM and EDX methods. While phenyl phosphinic acid is water-soluble, the synthesized hybrids are insoluble in water. Moreover, from TGA results, it can be observed that the thermal stability increased significantly for the obtained hybrids in comparison with the starting reagents. In addition, the EDX data confirmed the presence of phosphorus, as well as the presence of the used metals (Zr, V and Sn).

We report herein the synthesis, structural characterization and electrocatalytic properties of three new coordination polymers, resulting from the combination of divalent metal (Ca2+, Cd2+ or Co2+) salts with (2-carboxyethyl)(phenyl)phosphinic acid. In addition to the usual hydrothermal procedure, the Co2+ derivative could also be prepared by microwave-assisted synthesis, in much shorter times. The crystal structures were solved by ab initio calculations, from powder diffraction data. Compounds MII[O2P(CH2CH2COOH)(C6H5)]2 {M = Cd (1) or Ca (2)} crystallize in the monoclinic system and display a layered topology, with the phenyl groups pointing toward the interlayer space in a interdigitated fashion. Compound Co2[(O2P(CH2CH2COO)(C6H5)(H2O)]2·2H2O (3) presents a 1D structure composed of zig-zag chains, formed by edge-sharing cobalt octahedra, with the phenyl groups pointing outside. Packing of these chains is favored by hydrogen bond interactions via lattice water molecules. In addition, H-bonds along the chains are established with the participation of the water molecules and the hydrophilic groups from the ligand. However, the solid exhibits a low proton conductivity, attributed to the isolation of the hydrophilic regions caused by the arrangement of hydrophobic phenyl groups. Preliminary studies on the electrocatalytic performance for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) have been conducted for compound 3 and its pyrolytic derivatives, which were previously thoroughly characterized. By comparison, another Co2+ phosphinate, 4, obtained by microwave-assisted synthesis, but with distinct stoichiometry and a known structure was also tested. For the OER, the best performance was achieved with a derivative of 3, prepared by heating this compound in N2 at 200 °C. This derivative showed overpotential (339 mV, at a current density of 10 mA cm−2) and Tafel slope (51.7 mV dec−1) values comparable to those of other Co2+ related materials.

In the present work, novel organic-inorganic hybrids containing zirconium and phosphorus compounds were synthesized by using the sol-gel method, starting from zirconyl chloride hexahydrate (ZrOCl2·6H2O) and phenyl phosphonic acid (PPA). All the syntheses were performed at room temperature by using water as solvent. For some of the performed syntheses, alcohols with long hydrocarbon chain (n = 4–8) were added to the sol-gel process. They behave as nonionic surfactants due to their hydrophobic and hydrophilic groups, and they decrease the surface tension but without micelles formation, therefore without reaching CMC (critical micellar concentration). At a certain concentration, they will phase separate. This leads to the formation of a liquid/liquid interface. When the used alcohols were more hydrophobic, the obtained interface was more stable. This helped the synthesis and significantly changed its kinetics, as follows: in water, the chemical reaction was finished in 6 h, but when heptanol or octanol were added, the reaction time decreased to 3 h.

The present paper presents the obtaining and the characterization of a new complex acid dye by combining the transition metal Cu (II) with an azo acid dye, namely Amido Black 10B (C.I. 20.470), as ligand. The ligand and the resulted new azo complex were characterized by FT/IR spectroscopy, UV-Vis spectroscopy, AAs spectrometry, thermal analysis, and PXRD spectrometry. The structure of the ligand and the structure of the new synthesized copper complex were elucidated by all the above mentioned analysis methods. The formation of the azo metal complex with Cu(II) was confirmed by UV-Vis spectrum. Thermogravimetric and spectral analysis reveal its different stability in the air and nitrogen atmosphere, with high nitrogen stability. The PXRD analysis shows crystalline structure for the copper complex. At the same time, the color analysis was performed for the ligand and the synthesized complex in powder by means of UV-Vis CIEL*a*b* color space parameters, under the CIE recommended illuminants: D65 (natural day light), A (incandescent light) and F2 (fluorescent light) under the standard 10� observer angle. An important color phenomenon, namely metamerism, was highlighted for the complex, as well. Due to the presence of the Cu (II) ions, this azo complex presents a different color, calculated by the color differences AE*ab and AC*, a superior saturation and color strength than its ligand.

Thermal and crystallographic characterization of one solvent-free bis(iminophosphorane)ethane (BIPE) form and three solvates with acetonitrile (ACN), dimethyl sulfoxide (DMSO) and toluene is presented. Thermal behaviors of new compounds indicate that the solvent is removed differently from the BIPE structure, accordingly with the stoichiometric solvent molecule amount incorporated. Thus, the solvent-free BIPE reveals high thermal stability up to 315 °C, while BIPE solvates have a similar pattern behavior with low stability about 130 °C. The kinetic parameters of the thermal decomposition process were determined by three different methods Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose and nonparametric kinetic. Crystallographic data revealed that the solvent plays the role of space filler without strong interactions with host molecules. Guest-free BIPE, BIPE0.5ACN and BIPE0.35DMSO crystallized in monoclinic C2/c (№15) space group, while BIPETOLUENE in a triclinic P - 1 (№2) one. Crystallographic and thermogravimetric data show a good correlation between molecular structures and activation energies.

Hydroxyapatite is intensely studied not only for its bone repair applications but for many other applications, too. In this paper, hydroxyapatite obtained from calcium acetate and dimethyl phosphate was doped with two different metals, one being zirconium and the other one was chosen between M(II) and M(III) metals, under ultrasonication conditions. These types of compounds are not mentioned in the literature. The influence of the doped metals on the thermal behavior of hydroxyapatite precursors was studied using thermal analysis, UATR–FTIR spectrometry, energy dispersive X-ray analysis and ICPOS analysis.

Organophosphorus (OP) chemicals were broadly used as insecticides and in the treatment of human diseases such as malaria mosquitoes, parasitosis, myasthenia, and glaucoma. The OP toxicity is well known. They can cause environmental and health problems and have the possibility to accumulate in the food chain. The acceptable daily intake (ADI) can be considered as a measure of the effect of pesticide residues in food on human health. In this paper, the partial least squares (PLS) approach is used to evaluate the ADIs (expressed as pADIs) of a series of 46 structurally diverse OPs. OP structures were pre-optimized using the MMFF94s force field, and structural descriptors were calculated for the minimum energy conformers. This dataset was divided into 26 training compounds, and 20 pesticides were included in the prediction set. Several criteria to check the model robustness, overfitting, and the potential outliers in the X and Y space were employed. The PLS results indicated that new experimental toxicological data would be needed for five out of the 46 OPs, to improve their known ADI values, for qualitative and quantitative dietary long-term risk assessments.

Summary Aims Sports drinks, when used by adult athletes, can have significant performance benefits. Sports drinks provide carbohydrates, electrolytes and fluids to the body, and help the body hydration, before, during, and after physical activity. The carbohydrates supply the muscles with fuel during exercise. The main electrolyte from sport drinks is sodium, which improves the drive to drink and can assist with fluid replacement. One of the main aim of using sport drinks is hydration, without decreasing sodium level in order to prevent hyponatremia. The addition of protein may be beneficial to prevent muscle damage and may improve or maintain subsequent performance over consecutive days. Other active ingredients (as vitamins) may play a role in energy metabolism or in free radical defense, but are usually found in small amounts and it is unclear if they have any direct performance benefits. Caffeine improves reaction time and if consumed few hours before anaerobic/resistance exercise may improve the performance, but has no effect on repeated high-intensity training. Conclusion Sport drinks are useful only for adults athletes involved in endurance training, but are not recommended for children and adolescents. Sport drinks have the proper amounts and concentrations of carbohydrates and electrolytes to help the physical performance, in comparison with energy drinks, caffeinated energy drinks or other beverages.

Ultrasound technique represents a green method for the synthesis of different class of compounds. In this review, the progress in the synthesis of aminophosphonates, an important class of phosphorus derivatives having biological applications, under sonication, with or without catalysts or solvents, is presented. Aminophosphonates were obtained in very good yield from amines, aldehydes (ketones), and dialkyl or trialkyl phosphites under ultrasound. Ultrasound had a notable effect on the reaction conditions, the purity and yield of obtained compounds. Aminophosphonates which cannot be obtained by traditional methods were obtained when ultrasound is used.

Organophosphorus chemistry was developed in the last decade by promoting the synthesis reactions using ionic liquids either as solvent or catalyst. Ionic liquids (ILs), the so-called “green solvents”, have gained interest in the synthesis of organophosphorus compounds as alternatives to flammable and toxic organic solvents and catalysts. ILs have beneficial properties because they provide high solubility for many organic and inorganic compounds or metal complexes, have no vapor pressure, and are reusable. Also, in some cases, they can enhance the reactivity of chemical reagents. In this review, we aimed at showing the synthesis of different organophosphorus compounds under green and mild conditions using ILs as reaction media or catalysts, according to a trend developed in the last years. A novel trend is to perform these syntheses under microwave irradiation conditions together with ILs as solvents and catalysts.

The functionalization of S–1% DVB copolymer was carried out with aminophosphonate groups, and then the samples were covered with silica to obtain hybrid materials. The obtained hybrid materials were used as supports for impregnation of transition metal ions [Cu(II) and Mn(II)], and they were subsequently used as catalysts in oxidation reactions. The supports and catalysts were characterized by FTIR and UV–Vis spectroscopy, thermal analysis, SEM, and TEM electron microscopy. The results of FTIR spectroscopy indicated the formation of a hybrid of silica and an aminophosphonate polymer by the sol–gel route. The UV–Vis spectra showed a strong interaction of Cu(II) and a weak interaction of Mn(II) with aminophosphonate groups of the supports. The catalytic tests confirm different interactions between the metal cations and obtained supports. The formation of the immobilized Cu(II) complexes shows the possibility of using these materials selectively in oxidation of various organic compounds (anisole, cyclohexene, toluene, styrene, phenol). The purpose of this article is to develop some new poly(aminophosphonates)/silica hybrid materials immobilized with transition metal such as Cu(II) and Mn(II) ions for future use in the oxidation process.

Summary Introduction The main aim of the present review is to describe the advantages of using honey for general population and for athletes during endurance training, and to show its benefits as a healthy natural product, used as a huge energy source for human body. Conclusion Honey represents a sustainable and a natural food source which offers many advantages and health benefits through its antioxidant properties, antibacterial and antiseptic effects, as well as antifungal activity. Due to its properties and health benefits, an alternative medicine branch based on honey, called apitherapy, was developed during the last decades.

In this paper, we present the synthesis of tris(4-hydroxybutyl acrylate) phosphate using 1-methylimidazole as acid scavenger for hydrochloric acid by-product, when an ionic liquid is formed. The synthesis was performed in the absence of any organic solvent. The yield is 83% for ester. The phosphate was characterized by 1H–31P NMR and FTIR. The obtained phosphate is appropriate monomer for UV curing in the presence of photoinitiator. The obtained polymer was characterized by thermal analysis and LOI. The results showed good thermal stability and flame retardancy of UV-cured polymer.

This paper is designated to the development of flame retardant solid polymer electrolytes based on phosphorus containing polymers. The new green technique synthesis, respectively polycondensation under microwave irradiation of hexylphosphonic dichloride (HPD) with 4,4′-(1,3-phenylenediisopropylidene) bisphenol (bisphenol M) was described. 86% yield and 0.95 dl g −1 inherent viscosity were obtained. The polyphosphonate was characterized by FT-IR, 1 H and 31 P NMR spectroscopy, gel permeation chromatography, and thermal analysis. The polymer presents thermal stability, begins to lose weight above 280 °C. The influence of the reaction temperature and reaction time on yield and inherent viscosity for MW polycondensation was studied and the results were compared with the results of polycondensation reaction under conventional heating in similar conditions. Best results were obtained under microwave irradiation. Solid polymer electrolytes were obtained from the polyphosphonate complexed with different lithium salts using casting technique and the electrochemical properties were determined. The low activation energy of conduction determined for solid polymer electrolyte membrane with bis(oxalato)borate anions overcomes the activation energy request for relaxation process and this membrane presents the best conductivity. Also, the flammability of polyphosphonate and membranes was investigated by measuring limiting oxygen index values.

The chlorometylated styrene–divinylbenzene copolymer with different percent of divinylbenzene (code: S-6.7 DVB, S-12DVB, and S-15DVB) was functionalized with 3-hydroxybenzaldehyde for obtaining intermediated polymers. The aminotrimethoxysilanphosphonate groups were grafted by one-pot reactions in tetrahydrofuran using three components: polymers grafted with aldehyde groups (code: CHO-6.7, CHO-12, and CHO-15), 3-aminopropyltrimethoxysilane, diethylphosphite. The aminotrimethoxysilanphosphonate groups functionalized onto styrene-(6.7, 12, and 15%) divinylbenzene copolymer (code: PAF-6.7, PAF-12, and PAF-15) and evolution of the reaction were evidenced by FT-IR spectroscopy and porous structure by N2 adsorption-desorption, SEM microscopy. The thermal behavior of aldehydes and materials: PAF-6.7, PAF-12, and PAF-15 are different than initial polymer supports.

An understanding of the fate of organic compounds originating from plants in soil is crucial for determining their persistence and concentrations in the environment. Aristolochic acids are believed to be the causal agents that induce Balkan endemic nephropathy by food contamination through soil adsorption of humic acids, major components of soil. Aristolochic acids are active chemicals in Aristolochia plant species found in endemic villages. In this article, molecular structure interactions between 18 structures of aristolochic acids with an inserted humic acid structure were studied. These structures were optimized in vacuo and by periodic box simulation with water solvate using the computational molecular mechanics MM+ method with HyperChem software. The QSPR models were used for correlation of the relationship between the hydrophobicity values of 18 AA structures coupled with a HA structure by MM+ and QSAR+ properties. Computational hydrophobicity values were considered dependent variables and were related to the structural features obtained by molecular and quantum mechanics calculations by multiple linear regression approaches. The obtained model was validated, and the results indicated differing hydrophobicity between the MM+ and QSAR+ properties.

Vinylphosphonic acid is homopolymerized with dimethylvinylphosphonate by radical polymerization using using UV light and photoinitiator Darocur 4265 (3 wt%). The molar ratio between vinylphosphonic acid and dimethylvinylphosphonate is varied between 1:1 and 4:1, respectively. The obtained homopolymer of vinylphosphonic acid and copolymers are characterized by Fourier transform infrared spectroscopy (FTIR), thermal analysis and size exclusion chromatography - multi angle laser light scattering. The polymerization by UV light is efficient and an average molar mass of 34,200 g/mol is obtained for poly(vinylphosphonic acid) and in the range from 12,700 to 19,120 g/mol for copolymers, which also have a good thermal stability until 320 °C. The polymers structure allows the formation of random coil conformation. The copolymers are tested as inhibitors against corrosion of iron in NaCl aqueous solution, and, as a result, it was shown that these copolymers exhibit promising anticorrosion properties.

Polyphosphoesters are environmentally friendly and multifunctional materials. They were noted for their special properties, i.e. fire resistance, plasticity, lubricity, high physical-mechanical performance, thermal stability, and as degradable biopolymers which properties can be modified specifically to desired application in medicine, biology and agriculture. They have a wide range of application as: flame retardants, scaffolds for tissue engineering, gene carriers, drug delivery, carriers for the sustained release of nerve growth factor, pH/thermoresponsive materials, or as solid polymer electrolytes. In this paper we present our researches concerning the synthesis and application of polyphosphates, and polyphosphonates using different modern methods. Different approaches were used. These polyphosphoesters were used as solid polymer electrolytes for lithium polymer batteries by complexation of polyphosphoesters obtained from different phospho(n)ric dichlorides and aliphatic or aromatic diols with lithium salts. These polymers present two important features: they have good conductivity, around 10−6 S/cm, and are fire proof.

In this paper, the carcinogenic potential and mammalian toxicity on rodents, based on the quantitative relationship models between structure and biological activity (QSAR), were evaluated. The carcinogenicity and acute toxicity were evaluated by docking molecular physicochemical descriptors, on a series of 33 thiophosphonates. These properties, mainly hydrophobicity, electronic distribution, hydrogen bonding characteristics, molecule size and flexibility, and the presence of various pharmacophoric features, influence the behavior of molecule in a living organism, including bioavailability, transport properties, affinity to proteins, reactivity, toxicity, metabolic stability and many others. The model was validated using linear regression methods: principal component analysis (PCA), partial least squares (PLS) and multiple linear regression (MLR); non-linear regression methods: cluster analysis (CA) and discriminant analysis (DA); and neural network analysis: probabilistic neural network (PNN), identifying the best predictor.