- Binding and hydrolysis of soman by human serum albumin
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Human plasma and fatty acid free human albumin were incubated with soman at pH 8.0 and 25°C. Four methods were used to monitor the reaction of albumin with soman: progressive inhibition of the aryl acylamidase activity of albumin, the release of fluoride ion from soman, 31P NMR, and mass spectrometry. Inhibition (phosphonylation) was slow with a bimolecular rate constant of 15 ± 3 M-1 min-1. MALDI-TOF and tandem mass spectrometry of the soman-albumin adduct showed that albumin was phosphonylated on tyrosine 411. No secondary dealkylation of the adduct (aging) occurred. Covalent docking simulations and 31P NMR experiments showed that albumin has no enantiomeric preference for the four stereoisomers of soman. Spontaneous reactivation at pH 8.0 and 25°C, measured as regaining of aryl acylamidase activity and decrease of covalent adduct (pinacolyl methylphosphonylated albumin) by NMR, occurred at a rate of 0.0044 h -1, indicating that the adduct is quite stable (t1/2 = 6.5 days). At pH 7.4 and 22°C, the covalent soman-albumin adduct, measured by MALDI-TOF mass spectrometry, was more stable (t1/2 = 20 days). Though the concentration of albumin in plasma is very high (about 0.6 mM), its reactivity with soman (phosphonylation and phosphotriesterase activity) is too slow to play a major role in detoxification of the highly toxic organophosphorus compound soman. Increasing the bimolecular rate constant of albumin for organophosphates is a protein engineering challenge that could lead to a new class of bioscavengers to be used against poisoning by nerve agents. Soman-albumin adducts detected by mass spectrometry could be useful for the diagnosis of soman exposure.
- Li, Bin,Nachon, Florian,Froment, Marie-Therese,Verdier, Laurent,Debouzy, Jean-Claude,Brasme, Bernardo,Gillon, Emilie,Schopfer, Lawrence M.,Lockridge, Oksana,Masson, Patrick
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Read Online
- METHYLIDENEPHOSPHINE
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Methylidenephosphine 1 was formed by gas-phase or liquid-phase HCl-elimination from chloromethylphosphine 2 and unambiguously characterized by chemical trapping and spectroscopic analysis (MS, IR, 31P NMR).
- Pellerin, Bruno,Guenot, Pierre,Denis, Jean-Marc
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Read Online
- A Peanut-Like Sb-Embedded Polyoxoniobate Cage for Hydrolytic Decomposition of Chemical Warfare Agent
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A Sb-embedded polyoxoniobate has been originally synthesized under hydrothermal conditions. Particularly, the peanut-like [Sb2Nb24O72]18? cluster cage in 1 with C2h symmetry is composed of two 9-nuclear {SbNb9O33} motifs and one {Nb6O24} crown-shaped ring. The compound 1 present the novel structure of Sb-substituted sandwich-type polyoxoniobate with antimoniobate cluster cage. Decomposition catalytic studies indicate that compound 1 exhibits good hydrolytic activity and stability on the degradation of nerve agent simulant dimethylphosphonate (DMMP).
- Wu, Yan-Lan,Zhong, Zhuo-Hao,Wu, Ping-Xin,Sun, Yan-Qiong,Li, Xin-Xiong,Zheng, Shou-Tian
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Read Online
- {Nb288O768(OH)48(CO3)12}: A Macromolecular Polyoxometalate with Close to 300 Niobium Atoms
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A protein-sized (ca. 4.2×4.2×3.6 nm3) non-biologically derived molecule {Nb288O768(OH)48(CO3)12} (Nb288) containing up to 288 niobium atoms has been obtained, which is by far the largest and the highest nuclearity polyoxoniobate (PONb). Particularly, in terms of metal nuclearity number, Nb288 is the second largest cluster so far reported in classic polyoxometalate chemistry (V, Mo, W, Nb, and Ta). Nb288 can be described as a giant windmill-like cluster aggregate of six nanoscale high-nuclearity PONb units {Nb47O128(OH)6(CO3)2} (Nb47) joined together by six additional Nb ions. Interestingly, the 47-nuclearity Nb47 units generated in situ can be isolated and bridged by copper complexes to form an inorganic–organic hybrid three-dimensional PONb framework, which exhibits effective catalytic activity for hydrolyzing nerve agent simulant of dimethyl methylphosphonate. The unique Nb47 cluster also provides a new type of topology to very limited family of Nb-O clusters.
- Wu, Yan-Lan,Li, Xin-Xiong,Qi, Yan-Jie,Yu, Hao,Jin, Lu,Zheng, Shou-Tian
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Read Online
- Wet and dry processes for the selective transformation of phosphonates to phosphonic acids catalyzed by br?nsted acids
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A "wet"process and two "dry"processes for converting phosphonate esters to phosphonic acids catalyzed by a Bronsted acid have been developed. Thus, in the presence of water, a range of alkyl-, alkenyl-, and aryl-substituted phosphonates can be generally hydrolyzed to the corresponding phosphonic acids in good yields catalyzed by trifluoromethyl sulfonic acid (TfOH) at 140 °C (the wet process). On the other hand, with specific substituents of the phosphonate esters, the conversion to the corresponding phosphonic acids can be achieved under milder conditions in the absence of water (the dry process). Thus, the conversion of dibenzyl phosphonates to the corresponding phosphonic acids took place smoothly at 80 °C in toluene or benzene in high yields. Moreover, selective conversion of benzyl phosphonates RP(O)(OR′)(OBn) to the corresponding mono phosphonic acids RP(O)(OR′)(OH) can also be achieved under the reaction conditions. The dealkylation via the generation of isobutene of ditert- butyl phosphonate, and the related catalysis by TfOH took place even at room temperature to give the corresponding phosphonic acids in good to high yields. Nafion also shows high catalytic activity for these reactions. By using Nafion as the catalyst, phosphonic acids could be easily prepared on a large scale via a simple process.
- Li, Chunya,Saga, Yuta,Onozawa, Shun-Ya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
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p. 14411 - 14419
(2020/12/29)
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- Magnesium Exchanged Zirconium Metal-Organic Frameworks with Improved Detoxification Properties of Nerve Agents
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UiO-66, MOF-808 and NU-1000 metal-organic frameworks exhibit a differentiated reactivity toward [Mg(OMe)2(MeOH)2]4 related to their pore accessibility. Microporous UiO-66 remains unchanged while mesoporous MOF-808 and hierarchical micro/mesoporous NU-1000 materials yield doped systems containing exposed MgZr5O2(OH)6 clusters in the mesoporous cavities. This modification is responsible for a remarkable enhancement of the catalytic activity toward the hydrolytic degradation of P-F and P-S bonds of toxic nerve agents, at room temperature, in unbuffered aqueous solutions.
- Gil-San-Millan, Rodrigo,López-Maya, Elena,Platero-Prats, Ana E.,Torres-Pérez, Virginia,Delgado, Pedro,Augustyniak, Adam W.,Kim, Min Kun,Lee, Hae Wan,Ryu, Sam Gon,Navarro, Jorge A. R.
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supporting information
p. 11801 - 11805
(2019/08/28)
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- Synthesis of the Tripeptides Tyr-Thr-Lys Phosphorylated with Isopropyl Methyl- and (Deuteromethyl)phosphonochloridates as Reference Standards for the Analysis of Biomedical Samples
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A procedure for the phosphorylation of the tripeptide Tyr-Thr-Lys with isopropyl methyl- or (deuteromethyl)phosphonochloridate is developed. The phosphorylated tripeptides are intended for use as reference standards in the analysis of blood samples of people suspected to have been exposed to acetylcholinesterase inhibitors. Conditions of hromatographic separation and purification of the synthesized compounds are determined and optimized, which ensures the preparation of high-purity phosphorylated tripeptides.
- Rodin,Baygildiev,Krylov,Osipov,Krylov,Yashkir,Rybalchenko
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p. 2103 - 2107
(2019/11/29)
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- Investigating the breakdown of the nerve agent simulant methyl paraoxon and chemical warfare agents GB and VX using nitrogen containing bases
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A range of nitrogen containing bases was tested for the hydrolysis of a nerve agent simulant, methyl paraoxon (MP), and the chemical warfare agents, GB and VX. The product distribution was found to be highly dependant on the basicity of the base and the quantity of water used for the hydrolysis. This study is important in the design of decontamination technology, which often involve mimics of CWAs.
- Wilson, Craig,Cooper, Nicholas J.,Briggs, Michael E.,Cooper, Andrew I.,Adams, Dave J.
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supporting information
p. 9285 - 9291
(2019/01/03)
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- Methylphosphonic Acid Biosynthesis and Catabolism in Pelagic Archaea and Bacteria
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Inorganic phosphate is essential for all life forms, yet microbes in marine environments are in near constant deprivation of this important nutrient. Organophosphonic acids can serve as an alternative source of inorganic phosphate if microbes possess the appropriate biochemical pathways that allow cleavage of the stable carbon–phosphorus bond that defines this class of molecule. One prominent source of inorganic phosphate is methylphosphonic acid, which is found as a constituent of marine-dissolved organic matter. The cycle of biosynthesis and catabolism of methylphosphonic acid by marine microbes is the likely source of supersaturating levels of methane in shallow ocean waters. This review provides an overview of the rich biochemistry that has evolved to synthesize methylphosphonic acid and catabolize this molecule into Pi and methane, with an emphasis on the reactions catalyzed by methylphosphonic acid synthase MpnS and the carbon–phosphorus lyase system. The protocols and experiments that are described for MpnS and carbon–phosphorus lyase provide a foundation for studying the structures and mechanisms of these and related enzymes.
- Ulrich, Emily C.,Kamat, Siddhesh S.,Hove-Jensen, Bjarne,Zechel, David L.
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p. 351 - 426
(2018/05/16)
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- Decontamination of 2-chloro ethyl ethyl sulphide and dimethyl methyl phosphonate from aqueous solutions using manganese oxide nanostructures
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Current study investigates the efficiency of reactive adsorbent composed of MnO2 nanoparticles and nanorods for the detoxification of 2-chloro ethyl ethyl sulphide (CEES) and dimethyl methyl phosphonate (DMMP), well-known simulants of sulphur mustard and sarin, respectively. The MnO2 nanoparticles and nanorods were synthesised using novel reactive magnetron sputtering technique and then characterised by powder XRD, Raman spectroscopy, FE-SEM, TEM, BET, FT-IR and Thermogravimetry (TG) analysis. Powder XRD and Raman results confirm the formation of pure tetragonal phase of MnO2 nanostructure material. The FE-SEM and TEM analysis exhibited the formation of aggregate MnO2 nanoparticles and nanorods. The surface area of the synthesised aggregate MnO2 nanoparticles and nanorods (164.28 m2/g) was found to be enhanced significantly in comparison with what was reported in the literature. Decontamination reactions of synthesised nanostructure material were examined by GC equipped with FID and the products obtained after reaction were analysed by GC-MS and FT-IR techniques. It was observed that the currently synthesised MnO2 nanoparticles and nanorods exhibit much better decontamination results towards CEES as well as DMMP in comparison to or as per existing solid decontaminants. The reactions exhibited pseudo first order kinetic behaviour with rate constant and half life value 0.267 h- 1 and 2.58 h for CEES and 0.068 h- 1 and 10.10 h for DMMP, respectively. The data exhibits the formation of non-toxic hydrolysis products in the detoxification of CEES as well as DMMP.
- Verma, Monu,Chandra, Ramesh,Gupta, Vinod Kumar
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p. 285 - 292
(2016/01/09)
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- Broad-Spectrum Liquid- and Gas-Phase Decontamination of Chemical Warfare Agents by One-Dimensional Heteropolyniobates
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A wide range of chemical warfare agents and their simulants are catalytically decontaminated by a new one-dimensional polymeric polyniobate (P-PONb), K12[Ti2O2][GeNb12O40]?19 H2O (KGeNb) under mild conditions and in the dark. Uniquely, KGeNb facilitates hydrolysis of nerve agents Sarin (GB) and Soman (GD) (and their less reactive simulants, dimethyl methylphosphonate (DMMP)) as well as mustard (HD) in both liquid and gas phases at ambient temperature and in the absence of neutralizing bases or illumination. Three lines of evidence establish that KGeNb removes DMMP, and thus likely GB/GD, by general base catalysis: a) the k(H2O)/k(D2O) solvent isotope effect is 1.4; b) the rate law (hydrolysis at the same pH depends on the amount of P-PONb present); and c) hydroxide is far less active against the above simulants at the same pH than the P-PONbs themselves, a critical control experiment.
- Guo, Weiwei,Lv, Hongjin,Sullivan, Kevin P.,Gordon, Wesley O.,Balboa, Alex,Wagner, George W.,Musaev, Djamaladdin G.,Bacsa, John,Hill, Craig L.
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supporting information
p. 7403 - 7407
(2016/07/06)
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- Effective, Facile, and Selective Hydrolysis of the Chemical Warfare Agent VX Using Zr6-Based Metal-Organic Frameworks
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The nerve agent VX is among the most toxic chemicals known to mankind, and robust solutions are needed to rapidly and selectively deactivate it. Herein, we demonstrate that three Zr6-based metal-organic frameworks (MOFs), namely, UiO-67, UiO-67-NH2, and UiO-67-N(Me)2, are selective and highly active catalysts for the hydrolysis of VX. Utilizing UiO-67, UiO-67-NH2, and UiO-67-N(Me)2 in a pH 10 buffered solution of N-ethylmorpholine, selective hydrolysis of the P-S bond in VX was observed. In addition, UiO-67-N(Me)2 was found to catalyze VX hydrolysis with an initial half-life of 1.8 min. This half-life is nearly 3 orders of magnitude shorter than that of the only other MOF tested to date for hydrolysis of VX and rivals the activity of the best nonenzymatic materials. Hydrolysis utilizing Zr-based MOFs is also selective and facile in the absence of pH 10 buffer (just water) and for the destruction of the toxic byproduct EA-2192.
- Moon, Su-Young,Wagner, George W.,Mondloch, Joseph E.,Peterson, Gregory W.,DeCoste, Jared B.,Hupp, Joseph T.,Farha, Omar K.
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supporting information
p. 10829 - 10833
(2015/11/27)
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- Textile/metal-organic-framework composites as self-detoxifying filters for chemical-warfare agents
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Abstract The current technology of air-filtration materials for protection against highly toxic chemicals, that is, chemical-warfare agents, is mainly based on the broad and effective adsorptive properties of hydrophobic activated carbons. However, adsorption does not prevent these materials from behaving as secondary emitters once they are contaminated. Thus, the development of efficient self-cleaning filters is of high interest. Herein, we report how we can take advantage of the improved phosphotriesterase catalytic activity of lithium alkoxide doped zirconium(IV) metal-organic framework (MOF) materials to develop advanced self-detoxifying adsorbents of chemical-warfare agents containing hydrolysable P-F, P-O, and C-Cl bonds. Moreover, we also show that it is possible to integrate these materials onto textiles, thereby combining air-permeation properties of the textiles with the self-detoxifying properties of the MOF material. The silk of human kindness: Insertion of lithium alkoxides in zirconium metal-organic frameworks (MOF) which are then deposited on silk fibers gives rise to protective fabrics capable of self-detoxifying chemical-warfare agents. The fabrics combine the air-permeation properties of the textiles with the highly active phosphotriesterase catalytic activity of the MOF for the hydrolysis of P-F, P-O, and C-Cl bonds.
- L?pez-Maya, Elena,Montoro, Carmen,Rodríguez-Albelo, L. Marleny,Aznar Cervantes, Salvador D.,Lozano-Pérez, A. Abel,Cenís, José Luis,Barea, Elisa,Navarro, Jorge A. R.
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supporting information
p. 6790 - 6794
(2015/06/08)
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- Tripodal molecules for the promotion of phosphoester hydrolysis
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A series of low molecular weight tripodal amide/histidine-containing compounds (1-2) have been synthesised and shown to increase the rate of bis-(p-nitrophenyl) phosphate (BNPP) and soman (GD) breakdown in buffered aqueous solution. This journal is the Partner Organisations 2014.
- Hiscock, Jennifer R.,Sambrook, Mark R.,Cranwell, Philippa B.,Watts, Pat,Vincent, Jack C.,Xuereb, David J.,Wells, Neil J.,Raja, Robert,Gale, Philip A.
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supporting information
p. 6217 - 6220
(2014/06/09)
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- Catalytic degradation of the nerve agent vx by water-swelled polystyrene-supported ammonium fluorides
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The catalytic degradation of the nerve agent VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate) by water-swelled polymer-supported ammonium fluorides is described. VX (0.06-0.53 mol/mol F -) is rapidly degraded (t1/2 ～ 10-30 min) to form the G-analogue (O-ethyl methylphosphonofluoridate), which hydrolyzes (t 1/2 ～ 1-1.5 h) to the nontoxic EMPA (ethyl methylphosphonic acid). The toxic desethyl-VX is not formed. The catalytic effect of fluoride is maintained even when 6 equiv of VX are loaded. GB (O-isopropyl methylphosphonofluoridate) and desethyl-VX agents are also degraded under these conditions.
- Marciano, Daniele,Goldvaser, Michael,Columbus, Ishay,Zafrani, Yossi
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scheme or table
p. 8549 - 8553
(2011/12/04)
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- Visible-light C-heteroatom bond cleavage and detoxification of chemical warfare agents using titania-supported gold nanoparticles as photocatalyst
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Gold nanoparticles supported on TiO2 effect the detoxification of soman and VX nerve gases and yperite vesicant agent at room temperature upon visible light illumination.
- Neau, Tefan,Cojocaru, Bogdan,Parvulescu, Vasile I.,Omoghi, Vasile,Alvaro, Mercedes,Garcia, Hermenegildo
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supporting information; scheme or table
p. 4050 - 4054
(2011/07/29)
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- Facile hydrolysis-based chemical destruction of the warfare agents VX, GB, and HD by alumina-supported fluoride reagents
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(Chemical Equation Presented) A facile solvent-free hydrolysis (chemical destruction) of the warfare agents VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate), GB (O-isopropyl methylphosphonofluoridate or sarin), and HD (2,2′-dichloroethyl sulfide or sulfur mustard) upon reaction with various solid-supported fluoride reagents is described. These solid reagents include different alumina-based powders such as KF/Al2O3, AgF/KF/Al2O3, and KF/Al2O3 enriched by so-called coordinatively unsaturated fluoride ions (termed by us as ECUF-KF/Al2O3). When adsorbed on these sorbents, the nerve agent VX quickly hydrolyzed (t1/2 range between 0.1-6.3 h) to the corresponding nontoxic phosphonic acid EMPA as a major product (>90%) and to the relatively toxic desethyl-VX (1/2 range between 2.2-161 h). The reaction rates and the product distribution were found to be strongly dependent on the nature of the fluoride ions in the KF/Al2O 3 matrix and on its water content. All variations of the alumina-supported fluoride reagents studied caused an immediate hydrolysis of the highly toxic GB (t1/2 31P, 13C, and 19F MAS NMR.
- Gershonov,Columbus,Zafrani
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supporting information; experimental part
p. 329 - 338
(2009/04/10)
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- Wet oxidation process and system
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A process and system for the destruction of compounds having a carbon-hetero atom bond. The process includes wet oxidation at elevated temperature and pressure of an aqueous mixture of at least one compound having a carbon-hetero atom bond to substantially destroy the carbon-hetero atom bond of the at least one compound. The resulting oxidized material may be further treated in an advanced oxidation process to destroy any residual carbon-hetero atom bonds remaining.
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Page/Page column 5
(2008/06/13)
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- Process for the preparation of N-phosphonomethylglycine and derivatives thereof
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N-phosphonomethylamines are produced by reaction of an amine substrate with a halomethylphosphonic acid or salt thereof, a hydroxymethylphosphonic acid or salt thereof, or a dehydrated self-ester dimer, trimer or oligomer of hydroxymethylphosphonic acid. Among the products that may be prepared according to the process are N-phosphonomethylaminocarboxylic acids such as (e.g.) glyphosate, N-phosphonomethylaminoalkanols such as (e.g.) hydroxyethlaminomethylphosphonic acid, and N-acylaminomethylphosphonic acids such as (e.g.) N-carbamylaminomethylphosphonic acid. Certain reactions are conducted with a substantial excess of amine reactant in order to drive the conversion while avoiding excessive formation of bis(N-phosphonomethyl)amine by-products. Other reactions use a secondary amine substrate (such as iminodiacetic acid) and can be conducted at substantial equimolar ratios of halomethylaminomethylphosphonic acid or hydroxyaminomethylphosphonic acid to secondary amine reactant without significant formation of bis(phosphonomethyl)amine by-products. Further disclosed is a process for the preparation of hydroxymethylphosphonic acid self-ester dimers, trimers and oligomers by azeotropic dehydration.
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Page/Page column 28-29
(2010/02/11)
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- Analysis of chemical neutralization products of phosphonothiolates by gas chromatography mass spectrometry
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A series of phosphonothiolates, including the highly toxic O-Ethyl-S-(2-diisopropylamino) ethyl methylphosphonothioate (VX), have been subjected to chemical neutralization reaction with metallic sodium. The phosphonothiolates decompose to their respective phosphonic and phosphonothioic acids and this results in the detoxification of VX. GC/MS technique in both EI and CI mode has been applied for reaction monitoring and final identification of the neutralization products formed in this reaction.
- Gupta,Palit,Dubey,Raza
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p. 1631 - 1637
(2007/10/03)
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- Solid-phase synthesis of some alkyl hydrogen methylphosphonates
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Eleven alkyl hydrogen methylphosphonates of structure RO(HO) P(O)Me were made by phosphoramidite chemistry on hydroxymethyl polystyrene resin; R = Me, Et, n-Pr, i-Pr, n-Bu, n-hexyl, n-octyl, cyclohexyl, cycloheptyl, cyclooctyl, and 3,3-dimethylbutan-2-yl
- Barucki, Hubert,Black, Robin M.,Kinnear, Kenneth I.,Holden, Ian,Read, Robert W.,Timperley, Christopher M.
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p. 2279 - 2286
(2007/10/03)
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- Routes of photocatalytic destruction of chemical warfare agent simulants
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Selected imitants of chemical warfare agents such as dimethyl methylphosphonate (DMMP), diethyl phosphoramidate (DEPA), pinacolyl methylphosphonate (PMP), butylaminoethanethiol (BAET) were subjected to photocatalytic and sonophotocatalytic treatment in aqueous suspensions of TiO2. Complete conversion of the same mass of imitants to inorganic products was obtained within 600 min for DMMP, DEPA, PMP, but required a longer time for BAET. Sonolysis accelerated photodegradation of DMMP. No degradation was observed without ultraviolet illumination. Final products of degradation were PO43-, CO2 for DMMP and PMP, PO43-, NO3- (25%), NH4+ (75%), CO2 for DEPA, and SO42-, NH4+, CO2 for BAET. The number of main detected intermediate products increases in the order DMMP (7), DEPA (9), PMP (21), and exceeds 34 for BAET. Degradation of DMMP mainly proceeds through consecutive oxidation of methoxy groups and then the methyl group. Dimethyl hydroxymethylphosphonate and dimethylphosphate testify to the parallel oxidation of the methyl group. Destruction of DEPA mainly starts with cleavage of the P-NH2 bond to form diethyl phosphate, which transforms further into ethyl phosphate. Oxidation of α and β carbons of ethoxy groups to form ethylphosphonoamidate, hydroxyethyl ethylphosphonoamidate and other products also contributes to the destruction. Photocatalytic degradation of PMP mainly starts with oxidation of the pinacolyl fragment, methylphosphonic acid and acetone being the major products. Oxidation of BAET begins with dark dimerization to disulfide, which undergoes oxidation of sulfur forming sulfinic and sulfonic acids as well as oxidation of carbons to form butanal, aminobutane, etc., and cyclic products such as 2-propylthiazole. A scheme of degradation was proposed for DMMP and DEPA, and starting routes for PMP and BAET. Quantum efficiencies of complete mineralization calculated as reaction rate to photon flux ratio approximate 10-3%.
- Vorontsov, Alexandre V.,Davydov, Lev,Reddy, Ettireddy P.,Lion, Claude,Savinov, Eugenii N.,Smirniotis, Panagiotis G.
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p. 732 - 744
(2007/10/03)
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- Kinetics of destruction of diisopropyl methylphosphonate in corona discharge
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The kinetics of the destruction of diisopropyl methylphosphonate (DIMP) in corona discharge has been studied using a flow tubular coaxial wire dielectric barrier corona discharge reactor. The identification and quantitative determination of DIMP, its destruction intermediates, and phosphorus-containing destruction products were performed using molecular beam mass spectrometry and gas chromatography/mass spectrometry. Active discharge power was varied in the range 0.01-5 W. The destruction products such as isopropyl methylphosphonate, methylphosphonic acid, and orthophosphoric acid were found on the reactor walls. The dependence of the extent of the destruction, D(D = 1 - X/X0, where X and X0 are DIMP mole fractions at the outlet and the inlet of the reactor), on the specific energy deposition Ex(Ex = PF-1 X0-1, where F is the carrier gas flow and P is the power dissipated in discharge reactor) was measured over the DIMP mole fraction range 60-500 ppm at the pressure of 1 bar and the temperature of 340 K. Over the range of the experimental conditions studied the destruction obeys the pseudo-first-order kinetic law: 1n(1 - D) = -KEx. Plausible mechanisms of the destruction are discussed. It was concluded that ion mechanism is the major one responsible for the destruction process.
- Korobeinichev, Oleg P.,Chernov, Anatoly A.,Sokolov, Vladimir V.,Krasnoperov, Lev N.
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p. 331 - 337
(2007/10/03)
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- Dealkylation of dialkyl phosphonates with boron tribromide
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Boron tribromide cleanly and quantitatively converts dimethyl-, diethyl-, diisopropyl-, and ditertiobutyl phosphonates RP(O)(OR')2 into the corresponding phosphonic acids RP(O)(OH)2 via methanolysis. The use of boron tribromide is compatible with a variety of functionalities in the R group.
- Gauvry,Mortier
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p. 553 - 554
(2007/10/03)
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- Reactions of phosphonates with organohaloboranes: New route to molecular borophosphonates
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Phosphonates RPO(OR′)2 (R = Me, R′ = Et (1); R = CH2Ph, R′ = Et (2); R = CH double bond CH2, R′ = Et (3); R = CH2-CH double bond CH2, R′ = Me (4); R = CH2N3, R′ = Et (5)) react with CyBCl2 (6; Cy = C6H11) in a 1:1 molar ratio in toluene at -30 °C to form the primary adducts CyBCl2·O double bond PR(OR′)2 (7-11). These products undergo a thermally induced bis-chlorodealkylation with the formation of mixtures of oligomers [-O-PR(O-)-O-BCy(O-)]n (22-26) having isovalent P-O-B groupings. Under electron impact mass spectral conditions, the ions [RPO3BCy]4-Cy, which may be attributed to tetramers [RPO3BCy]4 (22′-26′), are detected. Compounds 22′-26′ presumably possess a central cubic M4O12P4 framework that is analogous to those found in alumino- and gallophosphate materials. NMR monitoring shows that [CyBCl(μ2-O)2PR(OR′)]2 (12-16) are formed as intermediates in these reactions. These unstable dimers 12-16 possess a cyclic core analogous to the single-four-ring (4R) secondary building units (SBUs) found in zeolites and phosphate molecular sieves. Hydrolysis of 12-16 and 22-26 with methanol at 30 °C gave respectively RPO(OH)(OR′) (17-21) and RPO(OH)2 (27-31). NMR monitoring reveals that the cyclic dimer [Me2B(μ2-O)2P(CH2Ph)(OEt)]2 (35a) is the primary adduct in the reaction of PhCH2PO(OEt)2 (2) with Me2BBr (34). Heating or prolonged storage at room temperature leads to a mixture of 35a, cyclic borophosphonate Me2BC(μ2-O)2P(CH2Ph)(OEt) (35b), and the mixed anhydride of benzylphosphonic acid and dimethylborinic acid (35c).
- Mortier, Jacques
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p. 4266 - 4275
(2008/10/08)
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- Thermocatalytic Oxidation of Dimethyl Methylphosphonate on Supported Metal Oxides
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Thermocatalytic oxidation of dimethyl methylphosphonate (DMMP) was carried out on nickel, iron, copper, and vanadium oxides supported on γ-Al2O3. The vanadium catalyst was found to exhibit exceptional catalytic activity, even better than platinum catalysts. Varying the vanadium loading from 1 to 15% by weight indicated that 10% vanadium on Al2O3 was an optimal content. In conjunction with XRD patterns, monolayer dispersion of V2O5 on Al2O3 was considered to be beneficial to the longevity of these catalysts. Different supports, including Al2O3, SiO2, and TiO2, were examined and SiO2 was the optimum support because of its large surface area and the ability to resist poisoning by P2O5. On 10% V/SiO2 catalysts, 100% (to our limit of detection of 0.1%) conversion of DMMP was reached for more than 100 h at 723 K. IR, X-ray powder diffraction, ion chromatography, and XPS results illustrated that the used catalysts contained phosphorus species. The presence of methylphosphonic acid on the catalyst surface and downstream of the packed bed reactor demonstrated the difficulty of P-CH3 cleavage. The deposition of coke in the catalyst bed and along the reactor wall resulted from the dehydration of methanol and DMMP on P2O5. Accumulation of phosphorus species and coke on catalysts gave rise to a tremendous loss of surface area. However, P2O5 itself was observed to catalyze the decomposition of DMMP. A mechanism for this reaction was proposed to explain these experimental observations.
- Cao, Lixin,Segal, Scott R.,Suib, Steven L.,Tang, Xia,Satyapal, Sunita
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- Loci of ceric cation mediated hydrolyses of dimethyl phosphate and methyl methylphosphonate
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(formula presented) Dimethyl phosphate and methyl methylphosphonate are cleaved by Ce(IV)-mediated hydrolysis with 91% and 88% P-O scission, respectively, and rate accelerations of ≥ 1010 relative to pH 7 P-O hydrolysis.
- Moss, Robert A.,Morales-Rojas, Hugo
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p. 1791 - 1793
(2008/02/11)
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- Broad spectrum catalytic system for the deep oxidation of toxic organics in aqueous medium using dioxygen as the oxidant
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In water, metallic palladium was found to catalyze the deep oxidation of a wide variety of functional organics by dioxygen at 80-90°C in the presence of carbon monoxide or dihydrogen. Several classes of organic compounds were examined: benzene, phenol and substituted phenols, nitro and halo organics, organophosphorus, and organosulfur compounds. In every case, deep oxidation to carbon monoxide, carbon dioxide, and water occurred in high yields, resulting in up to several hundred turnovers over a 24 h period. For substrates susceptible to hydrogenation, the conversions were generally higher with dihydrogen than with carbon monoxide. For organophosphorus compounds, the system presents the first examples of catalytic cleavage of phosphorus - alkyl bonds.
- Pifer, Anne,Hogan, Terrence,Snedeker, Benjamin,Simpson, Robert,Lin, Minren,Shen, Chengyu,Sen, Ayusman
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p. 7485 - 7492
(2007/10/03)
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- 9,10-Dicyanoanthracene-photosensitized elimination of 1,1'-binaphthalene from dinaphthyl methylphosphonate and trinaphthyl phosphate through the termolecular interaction in the singlet excited state
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9,10-Dicyanoanthracene (DCA) photosensitized intramolecular binaphthalene elimination of dinaphthyl methylphosphonates and trinaphthyl phosphates occurred through an exciplex between the singlet excited DCA (1DCA*) and the naphthyl group of dinaphthyl methylphosphonate and trinaphthyl phosphates in tetrahydrofuran, 1,4-dioxane, and benzene. Diethyl mononaphthyl phosphates also formed an exciplex with 1DCA*, while no reaction occurred. The binaphthalene elimination occurs via the intramolecular quenching of the exciplex by the second naphthyl group of dinaphthyl methylphosphonate or trinaphthyl phosphate, while the exciplex between the mononaphthyl phosphate and 1DCA* decays to give the starting compounds. The lifetime of the exciplex between the trinaphthyl phosphate and 1DCA* was shorter than that between the mononaphthyl phosphate and 1DCA*. The termolecular interaction (teraromatic groups interaction) of 1DCA* and two naphthyl groups of dinaphthyl methylphosphonate or trinaphthyl phosphate is suggested by the emission observation of the termolecular interaction of two naphthyl groups of trinaphthyl phosphate and 1,4-dicyanobenzene in the singlet excited state during the quenching of the intramolecular excimer of dinaphthyl methylphosphonate or trinaphthyl phosphates by 1,4-dicyanobenzene. The O-P(O)-O spacer is necessary for the binaphthalene elimination during the termolecular interaction in the singlet excited state.
- Nakamura, Mitsunobu,Miki, Masamichi,Majima, Tetsuro
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p. 2103 - 2109
(2007/10/03)
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- Inhibition of human gastric and pancreatic lipases by chiral alkylphosphonates. A kinetic study with 1,2-didecanoyl-sn-glycerol monolayer
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Enantiomerically pure alkylphosphonate compounds RR'P(O)PNP (R=C(n)H(2n+1), R'=OY with Y=C(n')H(2n'+1) with n=n' or n≠n'; PNP=p-nitrophenoxy) noted (RY), mimicking the transition state occurring during the carboxyester hydrolysis were synthesized and investigated as potential inhibitors of human gastric lipase (HGL) and human pancreatic lipase (HPL). The inhibitory properties of each enantiomer have been tested with the monomolecular films technique in addition to an enyzme linked immunosorbent assay (ELISA) in order to estimate simultaneously the residual enzymatic activity as well as the interfacial lipase binding. With both lipases, no obvious correlation between the inhibitor molar fraction (α50) leading to half inhibition, and the chain length, R or Y was observed. (R11Y16)s were the best inhibitor of HPL and (R10Y11)s were the best inhibitors of HGL. We observed a highly enantioselective discrimination, both with the pure enantiomeric alkylphosphonate inhibitors as well as a scalemic mixture. We also showed, for the first time, that this enantioselective recognition can occur either during the catalytic step or during the initial interfacial adsorption step of the lipases. These experimental results were analyzed with two kinetic models of covalent as well as pseudo-competitive inhibition of lipolytic enzymes by two enantiomeric inhibitors. Copyright (C) 1999 Elsevier Science Ireland Ltd.
- Cavalier, Jean-Francois,Ransac, Stephane,Verger, Robert,Buono, Gerard
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- Intramolecular Binaphthyl Formation from Radical Cations of Tri-1-naphthyl Phosphate and Related Compounds in Photoinduced Electron-Transfer Reactions Sensitized by 9,10-Dicyanoanthracene
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The photoinduced electron transfer of tri-1-naphthyl phosphate and related compounds sensitized by 9,10-dicyanoanthracene (DCA) in acetonitrile produces 1,1′-binaphthyl and the corresponding biaryl. The quenching rate constant of the DCA fluorescence is calculated to be equal to the diffusion-controlled rate constant from the Stern-Volmer analysis and the fluorescence lifetime measurement. The free energy change calculated from the redox potentials and excitation energy of the singlet excited DCA indicates that the quenching process occurs exergonically to give the tri-1-naphthyl phosphate radical cation and DCA radical anion through electron transfer from tri1-naphthyl phosphate to the singlet excited DCA at the diffusion-controlled rate. On the basis of spectroscopic and kinetic studies with laser flash photolysis, pulse radiolysis, and γ-radiolysis, the radical cation of tri-1-naphthyl phosphate forms an intramolecular π-dimer radical cation with face-to-face interaction between the two naphthyl groups within 8 ns of the electron pulse. The 1,1′-binaphthyl radical cation is eliminated at the rate constant of kr = 5.3 × 105 s~: from the intramolecular π-dimer radical cation. Branching ratios of the reaction pathways are estimated for the reactive intermediates such as the tri-1-naphthyl phosphate radical cation and its intramolecular π-dimer radical cation from the rate constants and quantum yields. The electron-withdrawing character of the P(O) group in the O-P(O)-O spacer is responsible for the elimination of the binaphthyl radical cation. The DCA-sensitized photoinduced electron-transfer reaction of the tri-1-naphthyl phosphate is compared with the direct photoreaction.
- Nakamura, Mitsunobu,Dohno, Reizo,Majima, Tetsuro
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p. 6258 - 6265
(2007/10/03)
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- Kinetics of phosphoryl transfer reactions of phosphoamino acids and esters in the presence of imidazole
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In the presence of imidazole N-phosphoamino acids were prompted to undergo ester exhanges on the phosphorus as well as N to O migration 10- 38 times faster than in the absence.Only phosphoserine and threonine methyl esters, were activated by imidazole to give similar reactions.For the diasteromeric N-phosphonoserine methyl ester containing a phosphorus-carbon bond, a stereoselective reaction occurred to provide an O-phosphonoserine derivative with an isomeric ratio of 65 to 35.The mehanism may involve the formation of pentacoordinate intermediates promoted by imidazole.Key words: phosphoryl transfer reaction, imidazole, stereoselectively, N-phosphoamino acids.
- Yan, Quing-Jin,Wang, Qian,Zhao, Yu-Fen
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p. 181 - 188
(2007/10/03)
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- Photolysis of 4-Methoxyphenyl Aryl Alkylphosphonates
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UV irradiation of bis(4-methoxyphenyl) methylphosphonate 1a in methanol gave 4,4'-dimethoxybiphenyl 2a as the main product through an intramolecular excimer.With 4-cyanophenyl-4-methoxyphenyl methylphosphonate 1b 4-cyano-4'-methoxybiphenyl 2c and 4-cyano-2-(4'-methoxyphenyl)phenyl methylphosphonate 4b were obtained through an intramolecular exciplex. 3-Cyanophenyl-4-methoxyphenyl methyl phosphonate 1c gave only 3-cyano-4'-methoxybiphenyl 2f.Methyl 4-methoxyphenyl 4-chlorobenzylphosphonate 5a gave dimethyl 4-chlorobenzyl 2-(4'-methoxyphenyl)phosphonate and dimethyl 2-(4'-methoxyphenyl)benzylphosphonate.
- Nakamura, Mitsunobu,Sawasaki, Kouiti,Okamoto, Yoshiki,Takamuku, Setsuo
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p. 141 - 146
(2007/10/02)
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- Catalytic Oxidation of Dimethyl Methylphosphonate
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The catalytic oxidation in air of dimethyl methylphosphonate (DMMP), a nerve gas stimulant, has been studied over laboratory-prepared Pt/Al2O3 as a function of Pt loading (0.5 or 2.0percent) and temperature (150, 250, or 400 deg C).At 250 deg C and residence time of 0.69 s, carbon balances indicate that 90-95percent of the C atoms in the DMMP feed were completely oxidized to CO2 during the periods when DMMP destruction was > 99percent (50 h for the 0.5percent Pt catalyst and 76 h for the 2.0percent Pt catalyst).Only after the end of these protection periods was methanol detected in the gaseous effluent.HPLC analysis of a product liquid showed that four intermediate P-containing compounds were formed: dimethyl phosphate (DMP), monomethyl phosphate (MMP), monomethyl methylphosphonate (MMMP), and methylphosphonic acid (MPA).A reaction scheme is proposed to account for the production of these intermediates by a series of oxidative and hydrolytic reactions.Different behavior was observed at 400 deg C.Although the period of complete DMMP destruction was very long ( > 135 h) with 0.5percent Pt catalyst, oxidation as measured by CO2 production was incomplete and the oxidation activity decreased with time on stream.At 400 deg C the hydrolytic reactions apparently become sufficiently efficient to effect complete DMMP conversion for extended periods despite the drop in oxidation activity.Several methods of characterizing deactivated catalyst provide incremental evidence that catalyst alumina reacts with product phosphoric acid to give AlPO4.
- Tzou, T. Z.,Weller, S. W.
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p. 370 - 374
(2007/10/02)
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- PHOTOLYSIS OF ARYL ESTERS OF TRI- AND TETRACOORDINATED PHOSPHORUS COMPOUNDS
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Upon UV excitation in methanol, some diaryl esters of alkly- or alkenyl phosphonates underwent an elimination of two aryl groups to give biaryls and the corresponding alkyl- or alkenylphosphonic acids.Tris(4-methoxyphenyl) phosphite also underwent a similar elimination to give 4,4'-dimethoxybiphenyl and 4-methoxyphenyl phosphonate.This interesting biaryl elimination was confirmed to proceed via a singlet intramolecular excimer by means of fluorescence spectra and Stern-Volmer analysis.
- Shi, Min,Yamamoto, Kiichi,Okamoto, Yoshiki,Takamuku, Setsuo
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- ORGANOPHOSPHORO(THIOPEROXIC) ACIDS: DIRECT OBSERVATION AND REACTIVITY
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Peracid oxidation of organophosphorothioic acids yields novel organophosphoro(thioperoxic) acids (PSOH-isomers) and tentatively their POSH-isomers evident by 31P NMR spectroscopy.These acids or their further oxidation products are phosphorylating and sulfurylating agents.
- Segall, Yoffi,Wu, Shao-Yong,Toia, Robert F.,Casida, John E.
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p. 473 - 476
(2007/10/02)
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- Process for the production of aliphatic phosphonic acids
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An improvement in the process for the manufacture of aliphatic phosphonic acid the improvement comprising maintaining the reaction zone volume at about 80 to 95 percent capacity of reactants and/or products by continuously adding diester of aliphatic phosphonic acid reactant up to about 60 percent of the total reaction time said reactant being added in an amount sufficient such that said reactants and/or products will always be present in said reactor so as to occupy at least 80 percent of the reaction zone volume during said reactant addition.
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- KINETICS AND MECHANISM OF HYDROLYSIS OF METHYLPHOSPHONFLUORIDIC ACID
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The acid catalyzed rate for hydrolysis of methylphosphonfluoridic aid has been determined at several hydrogen ion concentrations and temperatures.The acid hydrolysis is second order (in acid and substrate).Assumed rate expressions, observed rate constants, and hydrogen ion concentrations were used to calculate the thermodynamic equilibrium constant (Ka=0.56) and rate constants for acid catalysis.The activation energy Ea has been determined as 18.3 Kcal/mole.Finally, the acid catalyzed deuterolysis was determined to be about 1.47 times the rta of hydrolysis.The data suggest a two-step mechanism consisting of a rapid proton transfer, followed by slow hydration of the protonated complex.
- Bechtold, W. E.,Dahl, A. R.
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p. 193 - 202
(2007/10/02)
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- 3-acylamino-2-oxo-1-azetidinyl esters of phosphonic acids, phosphoric acid and phosphoric acid esters
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Antimicrobial activity is exhibited by β-lactams having a STR1 substituent in the 1-position and an acylamino substituent in the 3-position, or a pharmaceutically acceptable salt thereof; wherein Y is oxygen or sulfur and R5 is hydroxyl, alkyl, substituted alkyl, phenyl, substituted phenyl, alkoxy, alkylthio, (substituted alkyl)oxy, (substituted alkyl)thio, phenyloxy, phenylthio, (substituted phenyl)oxy or (substituted phenyl)thio.
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- Synergistic herbicidal compositions
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Synergistic herbicidal activity is displayed by compositions comprising the following two components: (a) a pyrrolidone of the formula STR1 in which X is selected from the group consisting of hydrogen, chlorine and methyl; Y is selected from the group consisting of hydrogen, chlorine and bromine; Z is selected from the group consisting of chlorine and bromine; R1 is selected from the group consisting of hydrogen and C1 -C4 alkyl; R2 is selected from the group consisting of hydrogen, halogen, C1 -C4 alkyl, acetyl, trifluoromethyl, nitro, cyano, C1 -C4 alkoxy, C1 -C4 alkylthio, C1 -C4 alkylsulfinyl, C1 -C4 alkylsulfonyl, trifluoromethylsulfinyl, trifluoromethylsulfonyl, pentafluoropropionamido, and 3-methylureido; and R3 is selected from the group consisting of hydrogen, C1 -C4 alkyl, chlorine and trifluoromethyl; and (b) a phosphonic acid of the formula STR2 in which R4 is selected from the group consisting of C1 -C4 alkyl, C1 -C4 haloalkyl, and --CH2 NHCH2 COOH, at a weight ratio of (a) to (b) of from about 0.1:1 to about 20:1.
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- DECOMPOSITION OF PHOSPHONATE ESTERS ADSORBED ON ALUMINUM OXIDE.
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Inelastic electron tunneling spectroscopy has been used to examine the adsorption and reaction of three phosphonate esters on aluminum oxide surfaces which were synthesized by the plasma oxidation of metallic aluminum films. The phosphonate esters were diisopropyl methylphosphonate (DIMP), dimethyl methylphosphonate (DMMP), and diphenyl methylphosphonate (DPMP). The adsorption temperatures ranged from 200 to 673 K. The exposures of gaseous DIMP and DMMP were 1. 0 torr multiplied by (times) s, while DPMP was exposed to the surface as a 0. 025 M solution in hexane. DIMP was found to adsorb molecularly in low coverages at 295 K, whereas at 373 K, DIMP was found to adsorb dissociatively in low coverages as isopropyl methylphosphonate. Above 373 K the isopropyl methylphosphonate decomposed to the metastable hydroxy methylphosphonate, which, in turn, decomposed completely to the methylphosphonate above 573 K.
- Templeton,Weinberg
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p. 774 - 779
(2007/10/02)
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- PHOSPHONAMIDATE COMPOUNDS
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Phosphonamidates of the formula STR1 wherein X is a substituted or unsubstituted imino or amino acid or ester. These compounds possess angiotensin converting enzyme activity and are thus useful as hypotensive agents.
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- Process for the manufacture of aliphatic phosphonic acids
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An improved process for the manufacture of an aliphatic phosphonic acid, particularly 2-chloroethylphosphonic acid, of the type wherein a diester of the aliphatic phosphonic acid, particularly bis-(2-chloroethyl)-2-chloroethylphosphonate, is reacted with anhydrous hydrogen halide, particularly hydrogen chloride, to produce a reaction product containing the aliphatic phosphonic acid, and the corresponding aliphatic halides particularly ethylene dichloride.
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- Multi-organ technetium complexes production and use thereof
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Chemical complexes, useful as radiopharmaceuticals, are formed by reacting technetium-99m with substituted or unsubstituted alkyl monophosphonic acids and certain ester derivatives thereof. The complexes are formed by reducing pertechnetate ion chemically or electrolytically in the presence of the phosphonic acid. By chemical modification of the phosphonic acid complexing agent, it is possible to "tailor" complexes for kidney, liver or bone imaging. The complexes are normally used in a physiologically acceptable aqueous medium.
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