1611-31-0Relevant articles and documents
ALUMINA-ACCELERATED METHANOLYSIS AND HYDROLYSIS OF ACYL AND PHOSPHORYL FLUORIDES
Posner, Gary H.,Ellis, Jerry W.,Ponton, John
, p. 191 - 198 (1982)
We have discovered that Woelm chromatographic γ-alumina substantially accelerates hydrolysis (and methanolysis) of acyl and phosphoryl fluorides.Compared to the corresponding homogeneous reactions, these heterogeneous alumina-promoted reactions occur about 250-350 times faster for acyl fluorides and about 1800-3000 times faster for phosphoryl fluorides.
Reaction of nerve agents with phosphate buffer at ph 7
Creasy, William R.,Fry, Roderick A.,McGarvey, David J.
, p. 7279 - 7286 (2012)
Chemical weapon nerve agents, including isopropyl methylphosphonofluoridate (GB or Sarin), pinacolyl methylphosphonofluoridate (GD or Soman), and S-(2-diisopropylaminoethyl) O-ethyl methylphosphonothioate (VX), are slow to react in aqueous solutions at midrange pH levels. The nerve agent reactivity increases in phosphate buffer at pH 7, relative to distilled water or acetate buffer. Reactions were studied using 31P NMR. Phosphate causes faster reaction to the corresponding alkyl methylphosphonic acids, and produces a mixed phosphate/phosphonate compound as an intermediate reaction product. GB has the fastest reaction rate, with a bimolecular rate constant of 4.6 × - 10-3 M-1s-1[PO43-]. The molar product branching ratio of GB acid to the pyro product (isopropyl methylphosphonate phosphate anhydride) is 1:1.4, independent of phosphate concentration, and the pyro product continues to react much slower to form GB acid. The pyro product has two doublets in the 31P NMR spectrum. The rate of reaction for GD is slower than GB, with a rate constant of 1.26 × - 10-3 M-1s-1 [PO43-]. The rate for VX is considerably slower, with a rate constant of 1.39 × - 10-5 M-1s-1 [PO43-], about 2 orders of magnitude slower than the rate for GD. The rate constant of the reaction of GD with pyrophosphate at pH 8 is 2.04 × - 10-3 min-1 at a concentration of 0.0145 M. The rate of reaction for diisopropyl fluorophosphate is 2.84 × - 10-3 min-1 at a concentration of 0.153 M phosphate, a factor of 4 slower than GD and a factor of 15 slower than GB, and there is no detectable pyro product. The half-lives of secondary reaction of the GB pyro product in 0.153 and 0.046 M solution of phosphate are 23.8 and 28.0 h, respectively, which indicates little or no dependence on phosphate.
Binding of a designed substrate analogue to diisopropyl fluorophosphatase: Implications for the phosphotriesterase mechanism
Blum, Marc-Michael,Loehr, Frank,Richardt, Andre,Ruterjans, Heinz,Chen, Julian C.-H.
, p. 12750 - 12757 (2006)
A wide range of organophosphorus nerve agents, including Soman, Sarin, and Tabun is efficiently hydrolyzed by the phosphotriesterase enzyme diisopropyl fluorophosphatase (DFPase) from Loligo vulgaris. To date, the lack of available inhibitors of DFPase has limited studies on its mechanism. The de novo design, synthesis, and characterization of substrate analogues acting as competitive inhibitors of DFPase are reported. The 1.73 A crystal structure of O,O-dicyclopentylphosphoroamidate (DcPPA) bound to DFPase shows a direct coordination of the phosphoryl oxygen by the catalytic calcium ion. The binding mode of this substrate analogue suggests a crucial role for electrostatics in the orientation of the ligand in the active site. This interpretation is further supported by the crystal structures of double mutants D229N/N120D and D229N/N175D, designed to reorient the electrostatic environment around the catalytic calcium. The structures show no differences in their calcium coordinating environment, although they are enzymatically inactive. Additional double mutants E21Q/N120D and E21Q/N175D are also inactive. On the basis of these crystal structures and kinetic and mutagenesis data as well as isotope labeling we propose a new mechanism for DFPase activity. Calcium coordinating residue D229, in concert with direct substrate activation by the metal ion, renders the phosphorus atom of the substrate susceptible for attack of water, through generation of a phosphoenzyme intermediate. Our proposed mechanism may be applicable to the structurally related enzyme paraoxonase (PON), a component of high-density lipoprotein (HDL).
Synthesis and Storage Stability of Diisopropylfluorophosphate
Heiss, Derik R.,Zehnder, Donald W.,Jett, David A.,Platoff, Gennady E.,Yeung, David T.,Brewer, Bobby N.
, (2016)
Diisopropylfluorophosphate (DFP) is a potent acetylcholinesterase inhibitor commonly used in toxicological studies as an organophosphorus nerve agent surrogate. However, LD50 values for DFP in the same species can differ widely even within the same laboratory, possibly due to the use of degraded DFP. The objectives here were to identify an efficient synthesis route for high purity DFP and assess the storage stability of both the in-house synthesized and commercial source of DFP at the manufacturer-recommended storage temperature of 4°C, as well as -10°C and -80°C. After 393 days, the commercial DFP stored at 4°C experienced significant degradation, while only minor degradation was observed at -10°C and none was observed at -80°C. DFP prepared using the newly identified synthesis route was significantly more stable, exhibiting only minor degradation at 4°C and none at -10°C or -80°C. The major degradation product was the monoacid derivative diisopropylphosphate, formed via hydrolysis of DFP. It was also found that storing DFP in glass containers may accelerate the degradation process by generating water in situ as hydrolytically generated hydrofluoric acid attacks the silica in the glass. Based on the results here, it is recommended that DFP be stored at or below -10°C, preferably in air-tight, nonglass containers.
Nerve agent degradation with polyoxoniobates
Kinnan, Mark K.,Creasy, William R.,Fullmer, Lauren B.,Schreuder-Gibson, Heidi L.,Nyman, May
, p. 2361 - 2367 (2014)
Polyoxoniobates are exceptional amongst polyoxometalates in that they can potentially perform base catalysis in water, a process in which a proton is bonded to an oxo ligand, and a hydroxyl is released. Catalytic decomposition of chemical warfare agents such as organofluorophosphates that were used recently in the infamous civilian attacks in Syria is one opportunity to employ this process. Upon evaluation of the polyoxoniobate Lindqvist ion, [Nb 6O19]8-, fast neutralization kinetics was discovered for the breakdown of the nerve agent simulant diisopropyl fluorophosphate (DFP). The polyoxoniobates were also tested against the nerve agents Sarin (GB) and Soman (GD). It was determined that different Lindqvist countercations (Li, K, or Cs) affect the rate of decomposition of the organophosphate compounds in both aqueous media (homogeneous reaction), and in the solid state (heterogeneous reaction). Small-angle X-ray scattering analysis of solutions of the Li, K, and Cs salts of [Nb6O19] 8- for concentrations at which the experiments were performed revealed distinct differences that could be linked to their relative reaction rates. This study represents the first demonstration of exploiting the unique alkaline reactivity of polyoxoniobates for nerve agent decontamination. Polyoxometalates, like small pieces of metal oxide, can be dissolved or fixed on a surface to perform homogeneous or heterogeneous catalysis, respectively. Here we exploit the alkaline nature of polyoxoniobates to neutralize nerve agents in both solution and the solid state. Solution studies correlate reaction efficacy to the association of the dissolved polyoxoniobate with its counterions. Copyright
Mixed-Metal Cerium/Zirconium MOFs with Improved Nerve Agent Detoxification Properties
Carmona, Francisco J.,Farzaneh, Faezeh,Geravand, Elham,Gil-San-Millan, Rodrigo,Navarro, Jorge A. R.
, p. 16160 - 16167 (2020)
A series of Ce/Zr mixed-metal-organic frameworks with different topology/connectivity, namely, Ce/Zr-UiO-66 (U01, U02, and U03) (fcu (12-c)), Ce/Zr-DUT-67-PZDC (D01 and D02) (reo (8-c)), and Ce/Zr-MOF-808 (M01, M02, and M03) (spn (6-c)) were evaluated toward the detoxification of toxic nerve agent model diisopropylfluorophosphate (DIFP) at room temperature in unbuffered aqueous solution. Noteworthily, the catalytic rate for P-F bond cleavage increased with increasing Ce/Zr molar ratio. A further increase in catalytic activity can be achieved by Mg(OMe)2 doping of the mixed-metal MOFs as exemplified with M01?Mg(OMe)2 and M02?Mg(OMe)2 systems. The results show that Mg(OMe)2 incorporation into the mesoporous cavities of M01 and M02 give rise to P-F hydrolytic degradation half-lives of nearly 5 and 2 min with 100% degradation of DIFP after 55 and 65 min for M01?Mg(OMe)2 1:2 and M02?Mg(OMe)2 1:4, respectively.
METHOD FOR PRODUCING PHOSPHOESTER COMPOUND
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Paragraph 0023; 0026-0028, (2021/09/27)
PROBLEM TO BE SOLVED: To provide a method whereby, a phosphate compound selected from the group consisting of orthophosphoric acid, phosphonic acid, phosphinic acid, and anhydrides of them is used as raw material and, by one stage reaction, a corresponding phosphoester compound is produced. SOLUTION: To an aqueous solution of a phosphate compound, added is an organic silane or siloxane compound having an alkoxy group or an aryloxy group, and the mixture is subjected to a heating reaction, thereby producing a corresponding phosphoester compound without requiring a catalyst. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
Green MIP-202(Zr) Catalyst: Degradation and Thermally Robust Biomimetic Sensing of Nerve Agents
Alberts, Erik M.,Cohen, Seth M.,Fernando, P. U. Ashvin Iresh I.,Harvey, Steven P.,Jenness, Glen R.,Kalaj, Mark,Kotagiri, Yugender Goud,Moores, Lee C.,Sandhu, Samar S.,Teymourian, Hazhir,Thornell, Travis L.,Tostado, Nicholas,Wang, Joseph
supporting information, p. 18261 - 18271 (2021/11/12)
Rapid and robust sensing of nerve agent (NA) threats is necessary for real-time field detection to facilitate timely countermeasures. Unlike conventional phosphotriesterases employed for biocatalytic NA detection, this work describes the use of a new, green, thermally stable, and biocompatible zirconium metal-organic framework (Zr-MOF) catalyst, MIP-202(Zr). The biomimetic Zr-MOF-based catalytic NA recognition layer was coupled with a solid-contact fluoride ion-selective electrode (F-ISE) transducer, for potentiometric detection of diisopropylfluorophosphate (DFP), a F-containing G-type NA simulant. Catalytic DFP degradation by MIP-202(Zr) was evaluated and compared to the established UiO-66-NH2 catalyst. The efficient catalytic DFP degradation with MIP-202(Zr) at near-neutral pH was validated by 31P NMR and FT-IR spectroscopy and potentiometric F-ISE and pH-ISE measurements. Activation of MIP-202(Zr) using Soxhlet extraction improved the DFP conversion rate and afforded a 2.64-fold improvement in total percent conversion over UiO-66-NH2. The exceptional thermal and storage stability of the MIP-202/F-ISE sensor paves the way toward remote/wearable field detection of G-type NAs in real-world environments. Overall, the green, sustainable, highly scalable, and biocompatible nature of MIP-202(Zr) suggests the unexploited scope of such MOF catalysts for on-body sensing applications toward rapid on-site detection and detoxification of NA threats.
Degradation of tri(2-chloroisopropyl) phosphate by the UV/H2O2 system: Kinetics, mechanisms and toxicity evaluation
He, Huan,Ji, Qiuyi,Gao, Zhanqi,Yang, Shaogui,Sun, Cheng,Li, Shiyin,Zhang, Limin
, (2019/07/31)
A photodegradation technology based on the combination of ultraviolet radiation with H2O2 (UV/H2O2) for degrading tri(chloroisopropyl) phosphate (TCPP) was developed. In ultrapure water, a pseudo-first order reaction was observed, and the degradation rate constant reached 0.0035 min?1 (R2 = 0.9871) for 5 mg L?1 TCPP using 250 W UV light irradiation with 50 mg L?1 H2O2. In detail, the yield rates of Cl? and PO43? reached 0.19 mg L?1 and 0.58 mg L?1, respectively. The total organic carbon (TOC) removal rate was 43.02%. The pH value of the TCPP solution after the reaction was 3.46. The mass spectrometric detection data showed a partial transformation of TCPP into a series of hydroxylated and dechlorinated products. Based on the luminescent bacteria experimental data, the toxicity of TCPP products increased obviously as the reaction proceeded. In conclusion, degradation of high concentration TCPP in UV/H2O2 systems may result in more toxic substances, but its potential application for real wastewater is promising in the future after appropriate optimization, domestication and evaluation.
Photocatalytic Aerobic Phosphatation of Alkenes
Depken, Christian,Kr?tzschmar, Felix,Rieger, Rene,Rode, Katharina,Breder, Alexander
supporting information, p. 2459 - 2463 (2018/01/27)
A catalytic regime for the direct phosphatation of simple, non-polarized alkenes has been devised that is based on using ordinary, non-activated phosphoric acid diesters as the phosphate source and O2 as the terminal oxidant. The title method enables the direct and highly economic construction of a diverse range of allylic phosphate esters. From a conceptual viewpoint, the aerobic phosphatation is entirely complementary to traditional methods for phosphate ester formation, which predominantly rely on the use of prefunctionalized or preactivated reactants, such as alcohols and phosphoryl halides. The title transformation is enabled by the interplay of a photoredox and a selenium π-acid catalyst and involves a sequence of single-electron-transfer processes.
