2465-65-8Relevant articles and documents
Ultra-fast catalytic detoxification of organophosphates by nano-zeolitic imidazolate frameworks
Ebrahimi, Arash,Mohammadsalehi, Maedeh,Nassireslami, Ehsan,Zibaseresht, Ramin
, (2020)
Detrimental and injurious impacts of Organophosphates that have had on environment, humans, organisms and the other animals or plants have not been surreptitious to anyone worldwide. Nevertheless, up to now, among many efforts that have been devoted to detoxification of Organophosphates (OPs), catalytic detoxification has been the most applicable, cost-effective, efficacious and safest way to break down these dangerous materials. Herein, the utilization of zeolitic imidazolate frameworks (ZIFs), for the first time, has been reported to deactivate Diazinon as an organophosphate agent demonstrated at room temperature. In the following research, the catalysts were analyzed by PXRD, FT-IR, FE-SEM, BET, CO2 adsorption/desorption and TG. The decontamination processes were followed by 31P NMR, HPLC, and UV–vis to evaluate catalytic efficiency. Interestingly, supreme reusability, durability and potentially stunning catalytic activity represent them as alternate materials for their amazing elimination of OPs compared to the other MOFs.
Pathways for the hydrolysis of phorate: Product studies by 31P NMR and GC-MS
Hong, Feng,Pehkonen, Simo O.,Brooks, Elwood
, p. 3013 - 3017 (2000)
A new intramolecular mechanism is proposed for the hydrolysis of phorate. 31P NMR was used to study the formation of P-containing products of phorate hydrolysis in situ. When hydrolysis was followed by 31P NMR, a dominant P-containing product was found and was identified to be diethyl dithiophosphate using methylation and GC-MS. Combining the data from phorate hydrolysis at three different temperatures, thermodynamic parameters were calculated. The contributions of various possible pathways to phorate hydrolysis are discussed.
Silica-Bound Sulfonic Acid Catalysts
Badley, Rickey D.,Ford, Warren T.
, p. 5437 - 5443 (1989)
The catalytic activity of colloidal silica sulfonic acid for the hydrolyses of diazinon and triphenylmethyl fluoride was compared with that of silica gel sulfonic acids, gel and macroporous poly(styrenesulfonic acids), powdered and soluble Nafion, p-toluenesulfonic acid, and hydrochloric acid.For diazinon hydrolysis, the colloidal catalyst was only slighty less active than the soluble strong acid catalysts and 2.8 times more active than any of other heterogeneous catalysts.The silica gel and polymeric sulfonic acid catalysts had similar activities.For triphenylmethyl fluoride hydrolysis all of the catalysts were only weakly active.
Nucleophilic reactions of phorate and terbufos with reduced sulfur species under anoxic conditions
Gan, Qiu,Jans, Urs
, p. 3546 - 3554 (2007)
The reactions of phorate and terbufos with bisulfide (HS-), polysulfide (Sn2-), thiosulfate (S2O 32-), and thiophenolate (PhS-) were examined in well-defined aqueous solution under anoxic conditions to investigate their role in the degradations of phorate and terbufos. Reactions were monitored at various concentrations of reduced sulfur species to obtain the second-order rate constants. The reactivity of the reduced sulfur species decreased in the order Sn2- > PhS- > HS- > S 2O32-. Hydrolysis products, formaldehyde and diethyl disulfide/di-tert-butyl disulfide, indicated that OH-/H 2O attacked the carbon atom between the two sulfur atoms, the so-called thioacetal carbon, which is very reactive due to the presence of the two neighboring sulfur atoms. The reaction of phorate and terbufos with PhS - was investigated to study the transformation products in the reactions with reduced sulfur species. The transformation products demonstrated that the observed increase in rate constants in the reaction with reduced sulfur species compared to hydrolysis could result from the nucleophilic attack of reduced sulfur species at the α-carbon of the ethoxy group and at the thioacetal carbon atom. The temperature dependence of measured second-order rate constants of the reaction of phorate and terbufos with HS- over 25-50°C was investigated to explore activation parameters, which are not significantly different for phorate and terbufos. All of the observations may imply similar pathways in the degradation of phorate and terbufos in the presence of reduced sulfur species. Slightly higher hydrolysis rates of terbufos and second-order reaction rate constants for the reactions with sulfur species of terbufos compared with those for phorate are observed, which could be attributed to the slightly different substituents.
Bifunctional Thiourea-Catalyzed Stereoablative Retro-Sulfa-Michael Reaction: Concise and Diastereoselective Access to Chiral 2,4-Diarylthietanes
Bacsó, András,Szigeti, Mariann,Varga, Szilárd,Soós, Tibor
, p. 429 - 439 (2016/12/24)
Owing to the chiral recognition capacity of bifunctional thioureas, a stereoablative retro-sulfa-Michael reaction has been developed. Utilization of a biphasic system enabled us to render the process catalytic. The usefulness of this methodology was further illustrated by the diastereoselective synthesis of all possible stereoisomers of 2,4-diarylthiethanes.
Reactivity and selectivity of the reaction of: O, O -diethyl 2,4-dinitrophenyl phosphate and thionophosphate with thiols of low molecular weight
Santos,Aliaga,Alarcón,Torres,Céspedes,Pavez
supporting information, p. 6479 - 6486 (2016/07/16)
A reactivity and selectivity study of O,O-diethyl 2,4-dinitrophenyl phosphate (1) and O,O-diethyl 2,4-dinitrophenyl thionophosphate (2) with a series of thiols of low molecular weight: N-acetyl cysteine (NAC), l-cysteine (Cys), homocysteine (Hcys), glutathione (GSH), and d-penicillamine (Pen) was conducted. Results show that (i) these nucleophiles only attack at the aromatic moiety of both triester derivatives, (ii) a kinetic control product by sulfhydryl attack of thiols was observed in the reactions of both triesters with Cys and Hcys, followed by an intramolecular amine attack leading to a thermodynamic control product. The kinetic study leads to the proposal of Meisenheimer complex formation and then proton transfer to the reaction media as the mechanism of these reactions.
Rapidly formed quinalphos complexes with transition metal ions characterized by electrospray ionization mass spectrometry
Keller, Bernd O.,Esbata, Abdelhamid A.,Buncel, Erwin,Van Loon, Gary W.
, p. 1319 - 1328 (2013/07/28)
RATIONALE Electrospray ionization tandem mass spectrometry (ESI-MS/MS) offers the unique opportunity to characterize complexes of the organophosphorus pesticide (OP) quinalphos (PA-Q) with transition metal ions immediately formed after contact. This study complements research looking at longer term kinetics of quinalphos hydrolysis in the presence of transition metal ions and gives insights into the structural features of the initial complex formation in solution. (Hydrolysis reaction: PA-Q + H2O → PA-OH + HQ, where PA-OH is the diethyl phosphate product and HQ is hydroxyquinoxaline.) METHODS Low micromolar PA-Q solutions with an approximately 3-fold molar excess of transition metal ions were immediately analyzed after mixing. Fragmentation of the transition metal ion complexes with PA-Q was accomplished in two different ways: first, in-source fragmentation by elevating the declustering potential and second, low-energy collision-induced dissociation (CID). RESULTS For Ag +, the [PA-Q - Ag+] and respective Ag+- containing degradation product ions are readily observed. For Cu2+, we observed the [PA-Q + Cu2+ + NO3-] complex ion with weak intensity and strong signals from both the [2PA-Q + Cu +] and the [PA-Q + Cu+] ions, the latter two attributable to charge-state reduction in the gas phase from Cu(II) to Cu(I), indicating that PA-Q fulfills specific structural requirements of the formed complex for charge-state reduction during transition from solution to the gas phase. For Hg2+, the [PA-Q + Hg2+ + (PA-OH - H)-] ion was the largest observed species containing one Hg2+ ion. No 1:1 species ([PA-Q] or other degradation products:Hg2+) was observable. CONCLUSIONS ESI-MS/MS of complexes formed from PA-Q and transition metal ions is a formidable technique to probe initial formation of these complexes in solution. Previous work from other groups established structural requirements that enable charge-state reduction from Cu(II) to Cu(I) in ligand complexes during transition into the gas phase, and these rules allow us to propose structural features of PA-Q complexes with copper ions in solution. Copyright 2013 John Wiley & Sons, Ltd. Copyright
Dual nucleophilic substitution reactions of O,O-diethyl 2,4-dinitrophenyl phosphate and thionophosphate triesters
Aguayo, Raul,Arias, Felipe,Canete, Alvaro,Zuniga, Carolina,Castro, Enrique A.,Pavez, Paulina,Santos, Jose G.
supporting information, p. 202 - 211 (2013/03/14)
The reactions of the title compounds with phenoxides, secondary alicyclic (SA) amines, and pyridines, in 44 wt% ethanol-water, at 25°C and an ionic strength of 0.2 M, were subjected to kinetic and product studies. From analytical techniques (HPLC and NMR), two pathways were detected (nucleophilic attack at the phosphoryl center and at the C-1 aromatic carbon) for the reactions of all the nucleophiles with the phosphate (2) and for the pyridinolysis of the thionophosphate (1). Only aromatic nucleophilic substitution was found for the reactions of 1 with phenoxides and SA amines. For the dual reactions, the nucleophilic rate constants (kN) were separated in two terms: documentclass{article}usepackage{amssymb} pagestyle{empty}begin{document}k-{rm N}^{rm P}end{document} and documentclass{article}usepackage{amssymb}pagestyle{empty}begin{document}k-{ rm N}^{{rm Ar}}end{document}, which are the rate constants for the corresponding electrophilic centers. The absence of a break in the Bronsted-type plots for the attack at P is consistent with concerted mechanisms. The Bronsted slopes, βAr 0.32-0.71, for the attack at the aromatic C-1, are in agreement with stepwise mechanisms where formation of a Meisenheimer complex is the rate-determining step. 2013 Wiley Periodicals, Inc. Int J Chem Kinet 45: 202-211, 2013 Copyright
The quality of chlorpyrifos Emulsifiable Concentrate formulations
Ahmed,Ahmed,Saleh,Ismail
, p. 661 - 671 (2013/06/27)
A STUDY was conducted to investigate the degradation of chlorpyrifos, as well as studying the formation of its impurity sulfotep after storage at 54 ±2 °C for 1,3, 7,14, 21 days, at 72 ±2 °C for 1-5 days, and at room temperature within range 1-12 weeks of three commercial chlorpyrifos Emulsifiable Concentrate (EC) formulations (48% w/v) from the Egyptian market (manufactured from three different companies). The obtained results showed that chlorpyrifos was more stable after storage at 54 ±2 °C and at room temperature, whereas the rate of degradation increased after storage at 72 +2 °C. There is no difference on the rate of degradation for all chlorpyrifos formulations under investigation. The sulfotep content of the three commercial formulations didn't show any correlation with storage temperature and storage time. However, in one of the commercial formulations of chlorpyrifos, the sulfotep content was more than the maximum permissible concentration of impurity recommended by FAO Specifications for chlorpyrifos (2008).
Synthesis of methylene bisphosphonates from carbon disulfide and phosphites via desulfurization: A mechanistic study
Heuze,Lemarie,Vazeux,Gulea,Masson,Sene,Jaffres,Alberti,MacCiantelli
experimental part, p. 820 - 829 (2009/12/03)
The reaction of carbon disulfide with an excess of sodium dialkylphosphite in an aprotic solvent led to the formation of the carbanion of methylene bisphosphonate and sodium thiophosphate. The mechanistic study of this unexpected reaction, using both 31P
