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  • 1
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 9 (1996), S. 145-151 
    ISSN: 0894-3230
    Keywords: Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Second-order rate constants of reactions of HO- with phosphate, phosphinate and thiophosphinate esters, (PhO)2PO.OC6H4NO2-p, Ph2PO.OC6H4NO2-p, Ph2PO.SPh, Ph2PO.SC6H4NO2-p and Ph2PO.SEt, go through minima with decreasing water content of H2O-MeCN or H2O-t-BuOH. The rate decrease is due to stabilization of the non-ionic ester on addition of organic solvent to H2O. This inhibition is partially offset by stabilization of the anionic transition states and in the drier solvents partial desolvation of HO- increases rates.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 11 (1998), S. 803-808 
    ISSN: 0894-3230
    Keywords: peroxymonosulfate ion ; oxidation ; sulfuric acid ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Peroxymonosulfate ion, HSO5-, as Oxone in aqueous H2SO4, oxidizes sulfides [MeSC6H4X(p), X = Me, H, NO2] to sulfoxides and converts aryl thiobenzoates [PhCOSC6H4X(p), X = Me, H] and thiol phosphorus(V) esters [Ph2POSPh, (EtO)2POSPh, Ph2POSEt, Ph(EtO)POSEt] into the acids and sulfonate ions. Second-order rate constants increase with increasing concentration of H2SO4 (10-53 wt%), owing to the high polarity of the medium rather than to acid catalysis. The rate increases fit the Grunwald-Winstein equation based on YOTs solvent parameters derived from rate effects on SN1 solvolyses. © 1998 John Wiley & Sons, Ltd.
    Additional Material: 7 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 10 (1997), S. 221-228 
    ISSN: 0894-3230
    Keywords: solvent effects ; hydroxide ; oximates ; phosphorus(V) esters ; nucleophilicity ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: ---Second-order rate constants of reactions of OH-, 2,3-butanedionemonooximate and 2-hydroxybenzaldoximate ions with aryl phosphate, phosphinate and thioarylphosphinate esters go through minima with decreasing water content of aqueous acetonitrile, tert-butyl alcohol and N-methyl-2-pyrrolidone. For reactions in H2O-MeCN the solvent effects are analyzed in terms of activity coefficients of the anionic nucleophiles and transition states. In the drier solvents partial desolvation of the nucleophiles increases rates. Nucleophilicities of several oximates and inorganic anions are compared in water. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 3 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 10 (1997), S. 427-434 
    ISSN: 0894-3230
    Keywords: phosphorus(V) esters of thiols ; peroxymonosulfate ion ; oxidative hydrolysis ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Peroxymonosulfate ion, HSO-5, as Oxone, readily converts phosphorus(V) esters of thiols into the phosphorus(V) and sulfonic acids. The esters were Ph2PO·SC6H4R(p) with R=MeO (1a), Me (1b), H (1c), Cl (1d) and NO2 (1e), (EtO)2PO · SPh (2), Ph2OI · SEt (3) and PhPO(OEt)SEt (4). Reactions are first order in each reactant and second-order rate constants, k2, for 1a-e fit the Hammett equation with ρ=-0.46. The rate constants increase markedly with increasing water content of H2O-MeCN, the activation enthalpies are low and the entropies are negative. Despite the low value of -ρ, these esters are much less reactive than thiol ethers, but the rate constants of reactions of these compounds and acyl thiols qualitatively follow the ionization potentials of the ethers and the esters. © 1997 John Wiley & Sons, Ltd.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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