Phosphoric Acid Derivatives Research Articles

Intercalation modified nano zirconium phosphate inhibitor for inhibiting coal spontaneous combustion

The synthesis and characterization of a modified zirconium phosphate (MZrP) nano-inhibitor for spontaneous coal combustion inhibition were explored through isooctylamine intercalation. Using oxidation experiment, FTIR and SEM, the variation rules of the characteristic parameters of the different coal samples were investigated. It was observed that MZrP exhibited enhanced dispersion within the coal matrix post-intercalation modification. As the MZrP concentration increased, there was a notable decrease in oxygen consumption rate, gas production concentration, and active group content in the coal, alongside a significant increase in apparent activation energy and inhibition efficacy. This enhanced inhibition is attributed to two primary mechanisms. Firstly, the hydrophilic nature of MZrP allows for its uniform distribution on the coal surface and within internal pores, creating a dense carbonized layer. This layer effectively retains moisture and isolates oxygen, enhancing physical inhibition. Secondly, MZrP inhibitor is thermally decomposed into phosphoric acid and its phosphoric acid derivatives, which can effectively capture the H- and -OH in the coal, and strengthens the inactivation of its reactive free radicals. The optimal inhibition was observed in coal samples treated with 6 wt% MZrP, exhibiting an average inhibition rate of 62.2 %, coupled with the lowest rates of gas production and oxygen consumption.

Chiral (S)-BINOL-phosphates: Design, synthesis and their antibacterial and α-glucosidase inhibition studies

A new series of chiral (S)-BINOL-derived phosphoric acid derivatives (8a-k) with 3,3′-disubstitution were successfully synthesized under microwave irradiation, yielding high product quantities within a short reaction time. The antibacterial and α-glucosidase inhibitory properties of these compounds were evaluated. Notably, compound 8b exhibited remarkable antibacterial efficacy against B. subtilis, S. aureus, S. epidermidis, P. aeruginosa, and K. pneumoniae, with a MIC value of 1.17 g mL−1. Furthermore, the electron-withdrawing nitro group-containing derivative, 8d displayed potent antibacterial activity (MIC = 1.17 g mL−1) against B. subtilis, S. epidermidis, and E. coli. Among the synthesized compounds, compound 8b, containing chloro substitutions at the 3,5-positions of the phenyl groups in (S)-3,3′-disubstituted BINOL, demonstrated the most noteworthy α-glucosidase inhibitory activity with IC50 value of 2.067 ± 0.017 M.

Dynamics of Coordinated Phosphonate Group Directly Observed by 17O-NMR in Lanthanide(iii) Complexes of a Mono(ethyl phosphonate) DOTA Analogue.

Biological phosphates can coordinate metal ions and their complexes are common in living systems. Dynamics of mutual oxygen atom exchange in the tetrahedral group in complexes has not been investigated. Here, we present a direct experimental proof of exchange ("phosphonate rotation") in model Ln(III) complexes of monophosphonate H4dota analogue which alters phosphorus atom chirality of coordinated phosphonate monoester. Combination of macrocycle-based isomerism with P-based chirality leads to several diastereoisomers. (Non)-coordinated oxygen atoms were distinguished through 17O-labelled phosphonate group and their mutual exchange was followed by various NMR techniques and DFT calculations. The process is sterically demanding and occurs through bulky bidentate (κ2-PO2)- coordination and was observed only in twisted-square antiprism (TSA) diastereoisomer of large Ln(III) ions. Its energy demands increase for smaller Ln(III) ions (298ΔG≠(exp./DFT)=51.8/52.1 and 61.0/71.5 kJ mol-1 for La(III) and Eu(III), respectively). These results are helpful in design of such complexes as MRI CA and for protein paramagnetic NMR probes. It demonstrates usefulness of 17O NMR to study solution dynamics in complexes involving phosphorus acid derivatives and it may inspire use of this method to study dynamics of phosphoric acid derivatives (as e. g. phosphorus acid-based inhibitors of metalloenzymes) in different areas of chemistry.

Chemistry, Metabolism and Neurotoxicity of Organophosphorus Insecticides: A Review

Organophosphorus compounds (OPs) are phosphoric acid derivatives represented by the formula (R2XP=O/S), R as organic groups; however, they need not contain a direct carbon-phosphorus bond. The organophosphorus compounds can be categorized into three classes, viz., organophosphates, carbamates nerve agents. The OPs having application as insecticides are generally phosphorothioates (i.e., containing P=S bond). These sulfur analogs are first bioactivated (in vivo) and converted to oxygen analogs responsible for exerting toxic action. These organophosphorus compounds are esters, fluorides, anhydrides, and amides of phosphoric, phosphorothioate, and phosphorodithioic acids. The toxicity of OPs is related to their molecular structure, metabolism in the targeted organisms, concentration, mode of decomposition, application, ingestion in organisms, etc. Exposure to OPs leads to the appearance of neurological symptoms followed by acute poisoning by targeting the target primarily, acetylcholine (AChE). However, secondary targets and other harmful effects besides nerve system problems are also reported. Organophosphates poison insects and other animals, including birds, amphibians, and mammals. These chemicals can have neural effects (Neurotoxicity), non-neuronal effects, or acute toxicity, which may also result in fatality. Their uncontrollable widespread became a significant threat to the environment; thus, corrective measures have been essential to save living beings and the environment from further damage.

Efficient synthesis of phosphorus containing melamine salt for enhancing flame retardancy of poly(lactic acid)/polyamide 11 blends

AbstractA tetrakis (melamine)‐1‐hydroxyethylidene‐1,1‐diphosphonic acid salt (EA‐MEL) was synthesized by a straightforward acid–base neutralization reaction between 1‐hydroxyethylidene‐1,1‐diphosphonic acid (EA) and melamine (MEL). This compound, which contains phosphorus and nitrogen elements, exhibits a 40% carbon residue at a temperature of 800°C. When combined with diethyl aluminium hypophosphite (OP1230) as a flame‐retardant composite in polylactic acid (PLA)/polyamide 11 blends through melt blending, a synergistic effect between the two flame retardants is observed. Consequently, the limiting oxygen index value significantly increases to 34.3, showcasing a remarkable 64.6% improvement. Additionally, the material achieves a V‐0 rating according to UL‐94 standards, and the peak heat release rate drops to 269 kW∙m−2 with the addition of just 5 wt% EA–MEL. These results demonstrate that EA‐MEL and OP1230 contribute to the generation of phosphoric acid derivatives and the formation of a crosslinked (PN)n or (PON)n network. This network enables the formation of a complete, compact, and expanded char residue, effectively isolating heat and oxygen.

Synergistic effect of phenyl phosphoric acid derivatives and DOPO on multifunctional epoxy resin: Fire safety, mechanical properties, transparency and hydrophobicity

A novel reactive flame retardant named PPDA was synthesized by neutralizing phenyl phosphate (PPOA) with 4,4′-diamino diphenyl ether (ODA). When 2.5 wt% of PPDA was incorporated into epoxy resin (EP) alongside 2.5 wt% of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), EP/PPDA/DOPO composite possessed UL-94 V-0 rating and a limited oxygen index (LOI) of 34.2% while exhibiting a remarkable synergistic effect between PPDA and DOPO. In contrast to pure EP, EP/PPDA2.5/DOPO2.5 exhibited a significant reduction in peak heat release rate, total heat release, and total smoke production by 56.3%, 23.0%, and 26%, respectively, when increasing char yield to 30.2%. The synergistic system formed char with organic phosphorus structures containing P-O-C, P-N-C, and P=O bonds, along with benzene rings in the condensed phase, meanwhile forming P-containing radicals and non-flammable nitrogen-containing compounds in the gas stage. Additionally, it was discovered that the presence of the NH bond in PPDA and the P-H bond in DOPO facilitated the ring-opening reaction of the epoxy groups, which contributed to the preservation of the mechanical properties and transparency of the EP. PPDA/DOPO was a halogen-free, low-cost alternative for flame retardants, demonstrating excellent performance and potential for future applications.

Surface coating of biomass-modified black phosphorus enhances flame retardancy of rigid polyurethane foam and its synergistic mechanism

A novel surface coating based on chitosan (CS) modified black phosphorus (BP) is obtained through layer-by-layer self-assembly and applied to flame-retardant rigid polyurethane foam (PUF). The CS-BP coating tightly adheres to the PUF surface through hydrogen bonding and electrostatic interaction, improving the PUF's thermal stability, photothermal conversion performance and fire safety performance without compromising its mechanical properties. The 9L-CS-BP/PUF exhibits reduced the peak of CO2 release, PHRR, and THR by 36.7%, 39.5%, and 28.8%, respectively, while increasing its residual carbon content by 35.2%. Moreover, a systematic comparison is made between the residual carbon inside and on the surface before and after combustion, and the results indicate that a large number of P-O-C structures and phosphoric acid derivatives are generated on the surface. The surface carbon layer formed by CS-BP effectively inhibited the thermo-oxidative degradation process of inner PUF. In the gas phase, modification of CS increases both the temperature range for the release of phosphorus-containing compounds during BP pyrolysis and the release of non-combustible gases during combustion, synergistically enhancing the gas-phase flame retardancy of CS-BP coating. This study provides a new approach to enhance the flame retardancy efficiency and broaden the application of BP-based flame retardants.

Synthetic Chemistry of Phosphoroselenoic Acid Derivatives with a Binaphthyl Group

The first synthetic example of phosphoric acids with a binaphthyl group appeared in 1971. Since then, their use as chiral molecular tools slowly increased. In contrast, the reports in 2004 that those acids with 3,3’-disubstituted binaphthyl groups catalyzed Mannich-type asymmetric reactions dramatically facilitated the development of catalytic reactions with those acids as chiral Brønsted acids. One simple idea to design isologues of those acids was the replacement of the oxygen atom of P=O and P-O groups with heavier elements in the Periodic Table. In fact, some isologues with a P=S bond appeared, but no derivatives with a P=Se bond were seen in 2001. We then started to develop the synthetic chemistry of selenium isologues of phosphoric acid derivatives with a binaphthyl group. The accidental finding of the formation of phosphoroselenoyl chlorides with a binaphthyl group stimulated our studies, and we developed a range of the derivatives with oxygen-, nitrogen-, and carbon-containing substituents on the phosphorus atom. Some of them can be used as a chiral discriminating agent, key starting materials to optically active alcohols, diselenides, organophosphorus compounds with a chiral carbon atom adjacent to the phosphorus atom, optically active trivalent organophosphorus compounds. During our studies, we also found the reaction involving the transfer of the axial chirality of a binaphthyl group to the central chirality of the phosphorus atom.

Design, Synthesis and Actual Applications of the Polymers Containing Acidic P-OH Fragments: Part 2-Sidechain Phosphorus-Containing Polyacids.

Macromolecules containing acidic fragments in side-groups—polyacids—occupy a special place among synthetic polymers. Properties and applications of polyacids are directly related to the chemical structure of macromolecules: the nature of the acidic groups, polymer backbone, and spacers between the main chain and acidic groups. The chemical nature of the phosphorus results in the diversity of acidic >P(O)OH fragments in sidechain phosphorus-containing polyacids (PCPAs) that can be derivatives of phosphoric or phosphinic acids. Sidechain PCPAs have many similarities with other polyacids. However, due to the relatively high acidity of −P(O)(OH)2 fragment, bone and mineral affinity, and biocompatibility, sidechain PCPAs have immense potential for diverse applications. Synthetic approaches to sidechain PCPAs also have their own specifics. All these issues are discussed in the present review.

Parahydrogen-Induced Hyperpolarization of Unsaturated Phosphoric Acid Derivatives

Parahydrogen-induced nuclear polarization offers a significant increase in the sensitivity of NMR spectroscopy to create new probes for medical diagnostics by magnetic resonance imaging. As precursors of the biocompatible hyperpolarized probes, unsaturated derivatives of phosphoric acid, propargyl and allyl phosphates, are proposed. The polarization transfer to 1H and 31P nuclei of the products of their hydrogenation by parahydrogen under the ALTADENA and PASADENA conditions, and by the PH-ECHO-INEPT+ pulse sequence of NMR spectroscopy, resulted in a very high signal amplification, which is among the largest for parahydrogen-induced nuclear polarization transfer to the 31P nucleus.

An Artificial SEI Layer Based on an Inorganic Coordination Polymer with Self‐Healing Ability for Long‐Lived Rechargeable Lithium‐Metal Batteries

AbstractUpon immersion of a lithium (Li) anode into a diluted 0.05 to 0.20 M dimethoxyethane‐solution of the phosphoric acid derivative (CF3CH2O)2P(O)OH (HBFEP), an artificial solid electrolyte interphase (SEI) is generated on the Li‐metal surface. Hence, HBFEP reacts on the surface to the corresponding Li salt (LiBFEP), which is a Li‐ion conducting inorganic coordination polymer. This film exhibits – due to the reversibly breaking ionic bonds – self‐healing ability upon cycling‐induced volume expansion of Li. The presence of LiBFEP as the major component in the artificial SEI is proven by ATR‐IR and XPS measurements. SEM characterization of HBFEP‐treated Li samples reveals porous layers on top of the Li surface with at least 3 μm thickness. Li−Li symmetrical cells with HBFEP‐modified Li electrodes show a three‐ to almost fourfold cycle‐lifetime increase at 0.1 mA cm−2 in a demanding model electrolyte that facilitates fast battery failure (1 M LiOTf in TEGDME). Hence, the LiBFEP‐enriched layer apparently acts as a Li‐ion conducting protection barrier between Li and the electrolyte, enhancing the rechargeability of Li electrodes.

Activated Monomer Mechanism (AMM) in Cationic Ring-Opening Polymerization. The Origin of the AMM and Further Development in Polymerization of Cyclic Esters.

The origin of the activated monomer mechanism (AMM) in cationic ring-opening polymerization (CROP) is described first. Then, conditions leading to the active chain end (ACE) mechanism and AMM are compared, as well as methods allowing to distinguish between these two mechanisms. These methods are based on the "ion trapping" of the active ionic species using highly basic phosphines or by comparing ACE and AMM kinetics of polymerization. The major factors deciding on the actual mechanism include: basicity of the monomers, ring strain, and the presence of the protic additives in the reaction system. These factors are tabulated for major cyclic ethers and cyclic esters. The historically evolved subsequent steps of AMM in the polymerization of cyclic esters are described: from the first experiments with trialkyloxonium salts, precursors of protonic acids, and added alcohols, via HCl as catalyst, and then CF3S(═O)2OH (polymerizing lactides) to the most popular derivatives of phosphoric acid, like diphenyl phosphate. Conditions allowing to synthesize poly(ε-caprolactone) (PCL), according to AMM-CROP, with molar mass up to 105 g·mol-1, are described as well as methods to polymerize CL with a protic initiator and acidic catalyst in one molecule. Then various methods enhancing the activity of the polymerizing systems are compared, based predominantly on hydrogen bonding, either to the polymer active end group (usually the hydroxyl group) or to the acid anion. Finally, kinetic equations for ACE and AMM are compared, and it is shown that the majority of the AMM-CROP systems, mostly studied for CL and lactides, proceed as living/controlled polymerizations. Since polymer end groups are hydroxyl groups, then, as it was shown in several papers, any initiator with one or many hydroxyl groups provides macromolecules with the corresponding architecture. The papers on synthetic methods are not discussed in detail.

Nazarov Cyclizations Catalyzed by BINOL Phosphoric Acid Derivatives: Quantum Chemistry Struggles To Predict the Enantioselectivity.

Quantum chemical calculations have successfully predicted the stereoselectivities of many BINOL phosphoric acid catalyzed reactions over the past 10-15 years. Herein we report a contrasting example: a reaction for which standard quantum chemistry techniques have proven unexpectedly ineffective at explaining the stereoselectivity. The Nazarov cyclizations of a divinyl ketone catalyzed by a BINOL phosphoric acid or H8-BINOL dithiophosphoric acid were studied with a conventional contemporary quantum chemical approach, consisting of transition state optimizations with B3LYP-D3(BJ) and single-point calculations with several functionals in implicit solvent. Unexpectedly, different functionals gave widely different predictions of the level of enantioselectivity and were unable even to agree on which enantiomer of the product would predominate. Molecular dynamics simulations with the OPLS-AA force field provided evidence that the transition state geometries optimized with DFT in the gas phase or in implicit solvent are not good representations of the true transition states of these reactions in solution. One possible reason for this, which may also explain the failure of quantum chemical techniques to reliably predict the enantioselectivity, is the fact that the transition states contain ion pairs which are not highly organized and do not contain any strongly directional noncovalent interactions between the substrate and the catalyst.

Organocatalytic Enantioselective Intramolecular (Hetero)Michael Additions in Desymmetrization Processes

AbstractThe organocatalytic enantioselective desymmetrization reaction by means of an intramolecular (hetero)Michael addition is a useful strategy for the creation of complex carbo‐ and heterocycles with the generation of multiple stereocenters in a very simple manner. The intramolecular addition of carbon, oxygen and nitrogen nucleophiles to prochiral substrates bearing electronically deficient olefins takes place in the presence of organocatalysts, such as chiral primary and secondary amines, NHCs, ureas, thioureas, and BINOL phosphoric acid derivatives, reaching high levels of diastereo‐ and enantioselectivity. The main bottleneck of this methodology is the design and synthesis of the starting materials, which compromises its application. To date, the majority of examples are related to the use of 1,4‐cyclohexanedione derivatives.

Insight into the Mechanism of the Acylation of Alcohols with Acid Anhydrides Catalyzed by Phosphoric Acid Derivatives.

Insight into the mechanism of a safe, simple, and inexpensive phosphoric acid (H3PO4)-catalyzed acylation of alcohols with acid anhydrides is described. The corresponding in situ-generated diacylated mixed anhydrides, unlike traditionally proposed monoacylated mixed anhydrides, are proposed as the active species. In particular, the diacylated mixed anhydrides act as efficient catalytic acyl transfer reagents rather than as Brønsted acid catalysts simply activating acid anhydrides. Remarkably, highly efficient phosphoric acid (1-3 mol %)-catalyzed acylation of alcohols with acid anhydrides was achieved and a 23 g scale synthesis of an ester was demonstrated. Also, phosphoric acid catalyst was effective for synthetically useful esterification from carboxylic acids, alcohols, and acid anhydride. Moreover, with regard to recent developments in chiral 1,1'-bi-2-naphthol (BINOL)-derived phosphoric acid diester catalysts toward asymmetric kinetic resolution of alcohols by acylation, some phosphate diesters were examined. As a result, a 31P NMR study and a kinetics study strongly supported not only the acid-base cooperative mechanism as previously proposed by other researchers but also the mixed anhydride mechanism as presently proposed by us.

Lubricating materials based on waste oleo products

Phosphatide concentrates and waste cooking oils - wastes that do not find qualified use and sources of environmental pollution, on the one hand, and on the other - valuable raw materials for the production of lubricating materials, additives and surfactants. The paper demonstrates the possibility of using these wastes as components in technologies for obtaining hydrated calcium greases and surfactants. By saponification of phosphatide concentrates and waste cooking oils were obtained the dispersed phases of thixotropic systems and were investigated their rheological properties. Derivatives of phosphoric acid in the composition of greases form a stronger structural framework, which is characterized by increased melting point and tribological properties capable of operating in high-load friction points. Surfactants were obtained by amidation of phosphatide concentrates and waste cooking oils. Synthesized alkanolamides combine with almost all mineral and synthetic oils and based on them developed compositions of lubricating materials. Tests of these compositions shown that synthesized surfactants from waste prove as effective multifunctional additives. Due to the chelating groups -OH, -NH2, -CONH, -COOH, -PO(OH)2, hydrophobic chelate complexes are formed, which not only impart systems homogeneity, but also provide improved protective, antioxidant and tribochemical properties of oils and lubricating compositions. Bench tests of resistance to oxidation of lubricating compositions with amidated phosphatide concentrates conducted at a temperature of 150 ºC confirmed their inhibitory effect, which allows to recommend them for use in high-temperature greases.

New Propargyl-Containing Derivatives of Phosphoric and Phosphonic Acids: Prospective Inhibitors of Acidic Corrosion of Steels for Oil Production

Based on propargyl alcohol esters, new derivatives of phosphorous and phosphonic acids of the acetylene series of various structures were synthesized (10 compounds). The prepared substances (6 compounds) significantly inhibit the corrosion of 08kp low-carbon steel in 5 M HCl (T = 20–60°C). The protective effect of these inhibitors increases with a rise in their content in solution and with increasing temperature. The strongest inhibition of steel corrosion is provided by phosphonic acid esters containing an alcohol group in their composition. For the synthesized corrosion inhibitors, an adsorption-polymerization mechanism of action is assumed, which is evidenced by the enhancement of the protective effect of these compounds with increasing temperature.

Phosphate-sensing with (di-(2-picolyl)amino)quinazolines based on a fluorescence on-off system.

Detection and visualization of phosphates such as ATP in living organisms can facilitate the elucidation of various biological events. Although substantial efforts had been made in this area, present methods have disadvantages such as the need for specialized equipment and poor sensitivities. To address these limitations, novel fluorescent probes, (di-(2-picolyl)amino)quinazolines, were developed for application in ATP detection. They selectively recognized copper ions by fluorescence quenching, and their copper complexes displayed fluorescence enhancement in the presence of phosphoric acid derivatives. This fluorescence on–off system enabled highly sensitive fluorescence detection of ATP when combined with a phenyl boronic acid-modified γ-cyclodextrin through a plausible multipoint recognition system.

Catechol-thiol-based dental adhesive inspired by underwater mussel adhesion

The critical problem associated with the underwater mussel adhesive catechol-based 3,4-dihydroxy-L-phenylalanine (DOPA) is its sensitivity to oxidation. To overcome this problem, mussels underwent etching in the presence of acidic pH conditions (<3.0), and thiol chemistry was used to control the propensity of DOPA for oxidation. Similar strategies deployed by mussels are also actively utilized in dental adhesives which undergo etching in the presence of phosphoric acid derivatives to maximize the bonding strength and adapt thiol chemistries to minimize shrinkage stress. In view of the similarities between dental and underwater mussel adhesives, we employ in this study the strategy of mussel adhesion—the combination of DOPA and thiol chemistry with acid etching—to one of the most critical issues in dental adhesives, namely, the dentin bonding with zirconia. As a result, the adhesion bonding between zirconia and dentin, one of the most elusive problems in dentistry, has improved compared to the commercially available adhesive resin formulation. In addition, in view of the similar human oral and mussel adhesive environments, our findings will considerably contribute to the translation of the adhesive system inspired by mussels. Statement of significanceMussels are effectively operated by creating an acidic environment when adhering with 3,4-dihydroxy-l-phenylalanine (DOPA)–thiol redox chemistry for underwater bonding. Similarly, in dental adhesives, phosphoric acid-based etching is used for dentin-bonding materials. In view of the similarity between dental adhesives and underwater mussel adhesives, the combination of DOPA and thiol chemistry with acid etching can be used to overcome one of the most critical issues in dentin medical adhesives. The proposed adhesion method produces high adhesion strengths compared to those currently used in dentin and zirconia adhesives. Here, we extend and evaluate dentin and zirconia dental adhesives by mixing with mussel (DOPA)–thiol redox chemistry and acid etching.

Comparative Metabolic Responses Induced by Pyridine and Imidazole in Blakeslea trispora.

Lycopene cyclase needs to be inhibited by the blockers like pyridine or imidazole in the lycopene accumulation of Blakeslea trispora. This work investigated how pyridine and imidazole impacted the basal metabolism of B. trispora, the results helped us understand how they could affect the lycopene production and application, and see the metabolic risks from different inhibitors. In this study, the highest yield of lycopene with pyridine was obtained at 176 mg/L without amino acids supplement, and got more lycopene at 237 mg/L adding tyrosine, lysine, proline all together as 0.01 mol/L each in fermented broth. GC-MS and Principal Component Analysis (PCA) were used to find that amino acids, fatty acids, organic acids including phosphoric acid, carbon source and imidazole derivatives played the most important roles in lycopene fermentation with imidazole, differently, fatty acids, carbon source, and pyridine derivatives were more significant in the pyridine process and it was remarkable that the residual of both blockers' derivatives would bring the potential risks on applications of lycopene products. Predominantly, durene met 0.35 mg/g DCW with imidazole and piperidine formaldehyde attained 0.24 mg/g DCW with pyridine after the end of lycopene fermentations.