A SEM-EDX Study on the Structure of Phenyl Phosphinic Hybrids Containing Boron and Zirconium.

The SEM-EDX method was used to investigate the structure and morphology of organic-inorganic hybrids containing zirconium, boron and phosphorus compounds, synthesized by the sol-gel method. We started by using, for the first time together, zirconyl chloride hexa-hydrate (ZrOCl2·6H2O), phenyl phosphinic acid and triethyl borate as precursors and reagents, at different molar ratios. The obtained hybrids showed a very high thermal stability and are not soluble in water or in organic solvents. As a consequence, such hybrid solid materials are suitable for applications at high temperatures. The obtained hybrids have complex 3D structures and form organic-inorganic networks containing Zr-O-Zr, Zr-O-P and Zr-O-B bridges. Such organic-inorganic networks are also expected to form supramolecular structures and to have many potential applications in different fields of great interest such as catalysis, medicine, agriculture, energy storage, fuel cells, sensors, electrochemical devices and supramolecular chemistry.

Wittig and Wittig-Horner Reactions under Sonication Conditions.

Carbonyl olefinations are among the most important organic syntheses that form C=C bonds, as they usually have high yields and in addition offer excellent stereoselectivity. Due to these advantages, carbonyl olefinations have important pharmaceutical and industrial applications. These reactions contain an additional step of an α-functionalized carbanion to an aldehyde or ketone to produce alkenes, but syntheses performed using metal carbene complexes are also known. The Wittig reaction is an example of carbonyl olefination, one of the best ways to synthesize alkenes. This involves the chemical reaction between an aldehyde or ketone with a so-called Wittig reagent, for instance phosphonium ylide. Triphenylphosphine-derived ylides and trialkylphosphine-derived ylides are the most common phosphorous compounds used as Wittig reagents. The Wittig reaction is commonly involved in the synthesis of novel anti-cancer and anti-viral compounds. In recent decades, the use of ultrasound on the Wittig reaction (and on different modified Wittig syntheses, such as the Wittig-Horner reaction or the aza-Wittig method) has been studied as a green synthesis. In addition to the advantage of green synthesis, the use of ultrasounds in general also improved the yield and reduced the reaction time. All of these chemical syntheses conducted under ultrasound will be described further in the present review.

The Influence of Boron on the Structure and Properties of Hybrid Compounds Containing Zirconium and Phosphorus.

In the present work, novel organic-inorganic hybrid materials containing boron, zirconium, and phosphorus were synthesized at different molar ratios, using the sol-gel method, starting from zirconyl chloride hexa-hydrate, triethyl borate, and phenyl phosphonic acid as the precursors. The sol-gel process is used for the first time in the present work in order to obtain organic-inorganic hybrids (or the so-called inorganic polymers) containing together boron, zirconium, and phosphorus. The sol-gel syntheses were performed at room temperature in ethanol. Zirconium containing compounds are already well known for their applications in medicine in restorative or prosthetic devices, including dental implants, knee and hip replacements, middle-ear ossicular chain reconstruction, and so on. Zirconium is a strong transition metal, which started to replace hafnium and titanium in the last decade in important applications. On the other hand, boron has the capability (similar to carbon) to form stable covalently bonded molecular networks. In addition to this capability, boron also offers mixed metallic and nonmetallic properties, because of its place on the periodic table, at the border between metals and nonmetals. Boron is responsible for the higher thermal stability of synthesized hybrid compounds. In the structure of those hybrid compounds, zirconium, boron, and phosphorus atoms are always connected via an oxygen atom, by P-O-Zr, Zr-O-Zr, or Zr-O-B bridges.

Hybrid Coordination Networks for Removal of Pollutants from Wastewater.

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).

Synthesis and electrochemical properties of metal(ii)-carboxyethylphenylphosphinates.

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.

Ld/Mm+ Simulation of Some Aristolochic and Humic Acids Species Coupled in Periodic Box with Water.

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 acid structures, from the 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. METHODS: 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-àvis of water-aromaticity or water-reactivity behaviors were observed.

Combined Experimental and Theoretical Insights into the Corrosion Inhibition Activity on Carbon Steel Iron of Phosphonic Acids.

The inhibition effect of N,N'-phosphonomethylglycine (PMG) and vinyl phosphonic acid (VPA) on the 3% NaCl acidic solution corrosion of carbon steel iron was studied at different immersion times by potentiodynamic polarization, electrochemical impedance spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and computational methods. It is found from the polarization studies that PMG and VPA behave as mixed-type inhibitors in NaCl. Values of charge transfer resistance (Rct) and double layer capacitance (Cdl) in the absence and presence of inhibitors are determined. The PMG and VPA inhibitors were capable of inhibiting the corrosion process up to ≈91% and ≈85%, respectively. In the presence of PMG, the synergic effect of chlorine ions was observed. Density functional theory (DFT) was engaged to establish the adsorption site of PMG, VPA, and their deprotonated states. For studied compounds, the resulted values of ELUMO, EHOMO, energy gap (∆E), dipole moment (µ), electronic hardness (η), global softness (σ), electrophilic index (ω), and the electronic potential map are in concordance with the experimental data results regarding their corrosion inhibition behavior and adsorption on the metal surface.

A Theoretical Study of the Molecular Coupled Structures of Aristolochic Acids and Humic Acid, Potential Environmental Contaminants.

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.

The antiviral activity and cytotoxicity of 15 natural phenolic compounds with previously demonstrated antifungal activity.

The present study attempted to evaluate the carcinogenicity of natural phenolic compounds with previously demonstrated antifungal activity, using a computational structure-cytotoxicity approach, namely the quantum structure cytotoxicity relationship model. The cytotoxicity of 15 phenolic compounds with antiviral activity 96 h after treatment was studied using the AdmetSAR computational program. Per the EPA classification, four of the investigated compounds would be included in the second cytotoxicity category, four in the third category, and six showed no toxicity, rendering the studied natural phenolic compounds much less toxic to aquatic life than synthetic pesticides, the organophosphorus compounds, which mostly fall into the first and second categories of toxicity.

Potential carcinogenicity predicted by computational toxicity evaluation of thiophosphate pesticides using QSTR/QSCarciAR model.

This study presents in silico prediction of toxic activities and carcinogenicity, represented by the potential carcinogenicity DSSTox/DBS, based on vector regression with a new Kernel activity, and correlating the predicted toxicity values through a QSAR model, namely: QSTR/QSCarciAR (quantitative structure toxicity relationship/quantitative structure carcinogenicity-activity relationship) described by 2D, 3D descriptors and biological descriptors. The results showed a connection between carcinogenicity (compared to the structure of a compound) and toxicity, as a basis for future studies on this subject, but each prediction is based on structurally similar compounds and the reactivation of the substructures of these compounds.

Molecular docking study to evaluate the carcinogenic potential and mammalian toxicity of thiophosphonate pesticides by cluster and discriminant analysis.

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.

Quantitative structure-activity/ecotoxicity relationships (QSAR/QEcoSAR) of a series of phosphonates.

In this paper the structure-toxicity relationship studies were performed for a series of 60 phosphonates. The toxicity of the compounds was determined by two ways: by quantifying the measured toxicity values, Mlog(1/MRIC50) collected by literature, for rodents species; second by using EcoSAR software version 1.11, for calculating the toxicity for fish species, considered as dependent variables and they were related to structural features obtained by molecular and quantum mechanics calculations. The QSAR/QEcoSAR was validated by multiple linear regression (MLR), although the purpose of this work was not to validate the model proposed, but rather to test the influence of structural parameters of the proposed model QSAR/QEcoSAR. The obtained models showed that the toxicity of phosphonates was influenced by steric and molecular geometry which cause inhibition of cholinesterase activity.

Grafted α-hydroxyphosphonic acids onto polymeric supports: preparation, characterization, and antimicrobial effect.

The paper deals with the preparation and characterization of compounds with antimicrobial activity: α-hydroxyphosphonic acids grafted onto styrene-12%-(15%)-divinylbenzene copolymer. These products proved to have antimicrobial effect against two species of gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two species of gram-positive bacteria (Staphylococcus aureus and Bacillus cereus) and a species of yeast (Candida albicans). Tests showed the reduction of bacterial load at different time intervals during the 18 h of contact.

Polymers containing phosphorus groups and polyethers: from synthesis to application.

BACKGROUND: Phosphorus-containing high performance polymers have aroused wide interest, mainly due to good mechanical properties and their excellent fire resistance. The flexibility of synthetic polyphosphoesters allows the development of polymers in order to obtain solid polymer electrolytes for rechargeable lithium batteries based on solid films with superior fire resistance. RESULTS: Novel linear Phosphonate-PEG polymers were synthesized by solution polycondensation of 4-chlorophenyldichlorophosphonate as a linking agent and poly(ethylene glycol)s with different molecular weights in the presence of triethylamine or 1-methylimidazole as acid scavenger. The yields were between 54% and 88% and inherent viscosity between 0.18-0.48 dl/g. Molar masses, Mn were about 26300 g/mol for polyphosphonates with PEG 2000 and 4600 g/mol for polyphosphonates with PEG 200. The LOI values for these polymers and membranes are in the range of 26-29. The membranes based on polyphosphonate with PEG 200 and 2000 showed conductivity between 6 × 10-8 S.cm-1 and 6 × 10-7 S.cm-1 at room temperature and total ionic transference number between 0.87- 0.96. The evolution of conductivity vs. temperature is linear. CONCLUSIONS: 1-methylimidazole was found to be better HCl scavenger than triethylamine, and allowed higher yields and more eco-friendly synthesis of the Phosphonate-PEG polymers for SPE. These polymers and membranes based on these polymers showed good LOI values and indicate an improvement of the safety of lithium batteries. The membranes present conductivities around 6 × 10-7 S.cm-1at room temperature and total ionic transference number is higher for membranes based on polymers with high EG unit content. Best results yield 88%, inherent viscosities 0.48 dl/g and Mn 26000 were obtained with 1-methylimidazole and PEG 2000. These membranes based on these polymers showed good LOI values (in the range 26-29%) and indicate an improvement of the safety of lithium batteries.

Structure simulation into a lamellar supramolecular network and calculation of the metal ions/ligands ratio.

BACKGROUND: Research interest in phosphonates metal organic frameworks (MOF) has increased extremely in the last two decades, because of theirs fascinating and complex topology and structural flexibility. In this paper we present a mathematical model for ligand/metal ion ratio of an octahedral (Oh) network of cobalt vinylphosphonate (Co(vP)·H2O). RESULTS: A recurrent relationship of the ratio between the number of ligands and the number of metal ions in a lamellar octahedral (Oh) network Co(vP)·H2O, has been deducted by building the 3D network step by step using HyperChem 7.52 package. The mathematical relationship has been validated using X ray analysis, experimental thermogravimetric and elemental analysis data. CONCLUSIONS: Based on deducted recurrence relationship, we can conclude prior to perform X ray analysis, that in the case of a thermogravimetric analysis pointing a ratio between the number of metal ions and ligands number around 1, the 3D network will have a central metal ion that corresponds to a single ligand. This relation is valid for every type of supramolecular network with divalent metal central ion Oh coordinated and bring valuable information with low effort and cost.

Synthesis of new phosphorus-containing (co)polyesters using solid-liquid phase transfer catalysis and product characterization.

This paper is directed towards the development of safe, and thermally stable solid polymer electrolytes. Linear phosphorus-containing (co)polyesters are described, including their synthesis, thermal analysis, conductivity, and non-flammability. Polycondensation of phenylphosphonic dichloride (PPD) with poly(ethylene glycol) (PEG 12000) with and without bisphenol A (BA) was carried out using solid-liquid phase transfer catalysis. Potassium phosphate is used as base. Yields in the range of 85.0-88.0%, and inherent viscosities in the range of 0.32-0.58 dL/g were obtained. The polymers were characterized by gel permeation chromatography, FT-IR, (1)H- and (31)P-NMR spectroscopy and thermal analysis. Their flammability was investigated by measuring limiting oxygen index values. The polymers are flame retardants and begin to lose weight in the 190 °C-231 °C range. Solid phosphorus- containing (co)polyesters were complexed with lithium triflate and the resulting ionic conductivity was determined. Conductivities in the range of 10(-7)-10(-8) S cm(-1) were obtained.

Divalent metal vinylphosphonate layered materials: compositional variability, structural peculiarities, dehydration behavior, and photoluminescent properties.

A family of M-VP (M = Ni, Co, Cd, Mn, Zn, Fe, Cu, Pb; VP = vinylphosphonate) and M-PVP (M = Co, Cd; PVP = phenylvinylphosphonate) materials have been synthesized by hydrothermal methods and characterized by FT-IR, elemental analysis, and thermogravimetric analysis (TGA). Their structures were determined either by single crystal X-ray crystallography or from laboratory X-ray powder diffraction data. The crystal structure of some M-VP and M-PVP materials is two-dimensional (2D) layered, with the organic groups (vinyl or phenylvinyl) protruding into the interlamellar space. However, the Pb-VP and Cu-VP materials show dramatically different structural features. The porous, three-dimensional (3D) structure of Pb-VP contains the Pb center in a pentagonal pyramid. A Cu-VP variant of the common 2D layered structure shows a very peculiar structure. The structure of the material is 2D with the layers based upon three crystallographically distinct Cu atoms; an octahedrally coordinated Cu(2+) atom, a square planar Cu(2+) atom and a Cu(+) atom. The latter has an unusual co-ordination environment as it is 3-coordinated to two oxygen atoms with the third bond across the double bond of the vinyl group. Metal-coordinated water loss was studied by TGA and thermodiffractometry. The rehydration of the anhydrous phases to give the initial phase takes place rapidly for Cd-PVP but it takes several days for Co-PVP. The M-VP materials exhibit variable dehydration-rehydration behavior, with most of them losing crystallinity during the process.

Effect of a phosphonium salt grafted on polymers on cucumber germination and initial growth

The aims of this study were the synthesis, characterization and the testing of vinyldiphenylphosphonium salt phytotoxicity. Phytotoxicity of the synthesised salt was tested on Cucumis sativus L. seed germination and early seedling growth, at five different concentrations, using a standardized toxicity test. Endpoints included the determination of some seedling parameters: root and shoot length, root and shoot biomass, root and shoot dry weight ratio and final germination percentage. The vinyldiphenylphosphonium salt showed moderate to strong root length and root biomass inhibition, which increases progressively with the increasd of the concentration level.