10463-05-5Relevant articles and documents
Dichotomy in the reactivity of trivalent phosphorus compounds Z3P (Z = Ph, nBu, OR) observed in the photoreaction with a ruthenium complex
Yasui, Shinro,Tsujimoto, Munekazu,Shioji, Kosei,Ohno, Atsuyoshi
, p. 1699 - 1707 (1997)
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.
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Boyd
, p. 742 (1970)
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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
Um, Ik-Hwan,Shin, Young-Hee,Lee, Seung-Eun,Yang, Kiyull,Buncel, Erwin
, p. 923 - 930 (2008)
(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).
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Dostrovsky,Halmann
, p. 502 (1953)
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Methanolysis of Phosphoramidates with Boron Trifluoride-Methanol Complex
Ryu, Seungmin,Jackson, John A.,Thompson, Charles M.
, p. 4999 - 5002 (2007/10/02)
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