- Dichotomy in the reactivity of trivalent phosphorus compounds Z3P (Z = Ph, nBu, OR) observed in the photoreaction with a ruthenium complex
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Solutions of tris(2,2′-bipyridyl)ruthenium(II) dichloride (Ru2+) and various types of trivalent phosphorus compounds Z3P (Z = Ph, nBu, OR; 1) in methanol have been photolyzed with visible light at 20 °C under an argon atmosphere, resulting in the oxidation of I to the corresponding pentavalent oxo compounds Z3P=O and ligand exchange of Ru2+ with 1. The former process takes place via single-electron transfer (SET) from 1 to Ru2+ in the photoexcited state, Ru2+*, which gene-rates the radical cation intermediate Z3P*+ from 1. The latter results from nucleophilic attack of 1 upon Ru2+*. The results show that 1 can act either as an electron donor or as a nucleo-phile toward Ru2+*. The rate constants for both processes are estimated. An excellent linear correlation is found between the logarithm of the SET rate and the oxidation potential for both the aromatic and aliphatic trivalent phosphorus compounds examined here; the slope of the plot is much less negative than expected on the basis of Rehm-Weller theory. Such behavior in the SET rates is interpreted by comparison with SET quenching by amines. On the other hand, a dualparameter correlation analysis shows that the ligand exchange is regulated by both steric and electronic factors in 1. WILEY-VCH Verlag GmbH, 1997.
- Yasui, Shinro,Tsujimoto, Munekazu,Shioji, Kosei,Ohno, Atsuyoshi
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- Rate and product studies with dimethyl phosphorochloridate and phosphorochloridothionate under solvolytic conditions
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The specific rates of solvolysis of dimethyl phosphorochloridate and of dimethyl phosphorochloridothionate are very well correlated using the extended Grunwald-Winstein equation, with incorporation of the NT solvent nucleophilicity scale and the YCl, solvent ionizing power scale. The sensitivity parameters (l and m) are similar to each other and also similar to previously recorded values for solvolyses of arenesulfonyl chlorides, which were proposed to follow a concerted displacement mechanism. For solvolyses in aqueous ethanol or aqueous methanol the product selectivities (S) are close to unity. For solvolyses in aqueous 2,2,2-trifluoroethanol, the values are too small to accurately measure, showing a very large preference for product formation involving nucleophilic attack by the water component. It is concluded that the chloride and chloridothionate solvolyses, in common with the solvolyses of arenesulfonyl chlorides, follow a concerted displacement mechanism.
- Kevill, Dennis N.,Carver, Jeffrey S.
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- Photodegradation of Cytrolane (mephosfolan) systemic insecticide in the aquatic environment using carbon-13 as a mass tracer
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Photodegradation of mephosfolan (Cytrolane, a registered trademark of the American Cyanamid Co.) was studied by exposing approximately equimolar mixtures of either 12C/13C-imido-labeled or 12C/13C-ethyl-labeled material to sunlight. Use of the 12C/13C mixtures facilitated identification of photoproducts by gas chromatography chemical ionization mass spectroscopy (GC-CIMS) because molecular and fragmentions in the mass spectra appear as doublets. Solvent artifacts and volatile rice paddy water constituents gave mass spectra containing only singlet ions and were ignored. Irradiations were conducted in distilled water, 'natural' water obtained from a flooded rice paddy, and a 2% acetone-water solution. The half-lives for mephosfolan were 18, 14, and 7 days, respectively, and indicated that photosensitization by paddy water constituents and acetone was occurring. The major products identified were cyclic S,S-propylene dithiocarbonate, 2-imino-5-methyl-1,3-dithiolane, and diethyl phosphate. Minor products were ethyl phosphate, phosphoric acid, and diethyl methyl phosphate.
- Ku,Kapoor,Stout,Rosen
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- Alkali metal ion catalysis and inhibition in nucleophilic displacement reactions at phosphorus centers: Ethyl and methyl paraoxon and ethyl and methyl parathion
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(Chemical Equation Presented) We report on the ethanolysis of the P=O and P=S compounds ethyl and methyl paraoxon (1a and 1b) and ethyl and methyl parathion (2a and 2b). Plots of spectrophotometrically measured rate constants, kobsd versus [MOEt], the alkali ethoxide concentration, show distinct upward and downward curvatures, pointing to the importance of ion-pairing phenomena and a differential reactivity of free ions and ion pairs. Three types of reactivity and selectivity patterns have been discerned: (1) For the P=O compounds 1a and 1b, LiOEt > NaOEt > KOEt > EtO-; (2) for the P=S compound 2a, KOEt > EtO- > NaOEt > LiOEt; (3) for P=S, 2b, 18C6-crown-complexed KOEt > KOEt = EtO- > NaOEt > LiOEt. These selectivity patterns are characteristic of both catalysis and inhibition by alkali-metal cations depending on the nature of the electrophilic center, P=O vs P=S, and the metal cation. Ground-state (GS) vs transition-state (TS) stabilization energies shed light on the catalytic and inhibitory tendencies. The unprecedented catalytic behavior of crowned-K+ for the reaction of 2b is noteworthy. Modeling reveals an extreme steric interaction for the reaction of 2a with crowned-K+, which is responsible for the absence of catalysis in this system. Overall, P=O exhibits greater reactivity than P=S, increasing from 50- to 60-fold with free EtO- and up to 2000-fold with LiOEt, reflecting an intrinsic P=O vs P=S reactivity difference (thio effect). The origin of reactivity and selectivity differences in these systems is discussed on the basis of competing electrostatic effects and solvational requirements as function of anionic electric field strength and cation size (Eisenman's theory).
- Um, Ik-Hwan,Shin, Young-Hee,Lee, Seung-Eun,Yang, Kiyull,Buncel, Erwin
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- PHOSPHORIC ACID DIESTER SALT, PRODUCTION METHOD THEREFOR, NON-AQUEOUS ELECTROLYTIC SOLUTION FOR POWER STORAGE ELEMENT, AND POWER STORAGE ELEMENT
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Disclosed is a phosphoric acid diester salt which can suppress deterioration of charge-discharge characteristics of a power storage element, and can suppress the rise in internal resistance after storage at high temperature, a production method therefor, a non-aqueous electrolytic solution for a power storage element, and a power storage element. Disclosed is a phosphoric acid diester salt represented by the following chemical formula (1): wherein Mn+ represents a hydrogen ion, an alkali metal ion, an alkali earth metal ion, an aluminum ion, a transition metal ion, or an onium ion; R1 and R2 are different from each other and represent a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group having 1 to 10 carbon atoms and having at least one of a halogen atom, a heteroatom, and an unsaturated bond; and n represents a valence.
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Paragraph 0159
(2018/09/12)
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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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- Synthesis of Mixed Trialkyl Phosphates: Oxidative Phosphorylation of Alcohols with Dialkyl Phosphonates in the Presence of Copper(II) Chloride
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Mixed trialkyl phosphonates were synthesized by oxidative phosphorylation of alcohols with dialkyl phosphonates and oxygen in the presence of copper(II) chloride in fairly good yields.
- Okamoto, Yoshiki,Kusano, Tetuya,Takamuku, Setsuo
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p. 3359 - 3361
(2007/10/02)
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- CATALYTIC EFFECT OF CESIUM FLUORIDE FOR ALKYLATION OF PHOSPHORIC ACIDS
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The phosphoric acids were smoothly alkylated with alkyl halides in the presence of cesium fluoride.KEYWORDS - phosphorylation; phosphotriester; cesium fluoride; alkylation
- Takaku, Hiroshi,Kamaike, Kazuo,Mori, Hisashi,Ishido, Yoshiharu
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p. 2157 - 2159
(2007/10/02)
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- Phosphoric-Carboxylic Imides. 2. Solvolytic Cleavage of the Nitrogen-Carbonyl and Nitrogen-Phosphoryl Bonds
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The neutral and acid-catalyzed solvolysis (hydrolysis and alcoholysis) of mixed phosphoric-carboxylic imides (1), X2P(O)-NR-C(O)R'(X = EtO, MeO, CH2O, Et; R = H, Me; R'= Me, Ph) has been studied and compared with the solvolytic behavior of parent phosphoric and carboxylic amides and symmetrical imides.The neutral cleavage of the P-N bond is believed to involve an oxyphosphorane intermediate.The ionization of 1 follows the amide acidity function, with half-protonation at the carbonyl oxygen atom occuring at ca. 70percent D2SO4.The remarkable stability of the P-N bond in acidic solutions, together with the susceptibility of the N-C(O)solvolysis toward acid catalysis, is consistent with the exclusion of the N-protonation of 1 and is in accordance with carbonyl oxygen protonation and the significant electron-withdrawing effect of the N-phosphinyl substituent.The hydration parameter treatment was applied to the acid-catalyzed N-C(O) hydrolysis of 1d (1, X = EtO; R = R'= Me), and the results are compared with those obtained for the acid-catalyzed hydrolysis of N-methylacetamide.The acidic solvolysis of 1, with respect to both the P(O)-N and N-C(O) cleavage, lies between the extremes characterized by the respective parent amides and symmetrical imides.
- Mizrahi, V.,Modro, T. A.
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p. 3030 - 3037
(2007/10/02)
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- MERCURIMETRY OF PHOSPHOROUS TRIESTERS AND OF SOME OTHER ORGANIC P(III) COMPOUNDS
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Non-hindered trialkyl(aryl)phosphites reduce mercuric acetate to metallic mercury in methanolic solution.The reaction is fast enough to allow direct titration by potentiometry, using a Pt electrode; adding a little Et3N is beneficial.Phosphorous diesters do not interfere, but halide ions disturb the titration.Alkylphosphonous dialkylesters behave like phosphorous triesters but dialkylphosphinous esters and trialkyl- or triarylposphines give rise only to complexes.The reaction products of the titration of (EtO)3P are mixed phosphates (MeO)n(EtO)3-nPO (n=0,1,2), AcOH, AcOMe, AcOEt, Me2O, MeOEt and Hg.The mechanism is discussed.
- Demarcq, M. C.
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