Ethyl hydroperoxide hydrogen peroxide determination

Henry s law constants, 698 hydrogen peroxide determination, 629, 638 hydroperoxide determination, 678 Al-Ethyl-Al-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyanUine, 632, 634 Al-Ethyl-Al -methyl imidazohum (emim), transition metal peroxides, 1083 Ethyl plakortide Z, namral occurrence, 610... 

Concerning the mode of formation of ES, we prefer the concept that the substrate in a monolayer is chemisorbed to the active center of the enzyme protein, just as the experimental evidence pertaining to surface catalysis by inorganic catalysts indicates that in these reactions chemisorbed, not physically adsorbed, reactants are involved. Such a concept is supported by the demonstration of spectroscopically defined unstable intermediate compounds between enzyme and substrate in the decomposition by catalase of ethyl hydroperoxide,11 and in the interaction between peroxidase and hydrogen peroxide.18 Recently Chance18 determined by direct photoelectric measurements the dissociation con-... 

O Sullivan, D.W., Lee, M., Noone, B.C.,andHeikes, B.G. Henry s law constant determinations for hydrogen peroxide, methyl hydroperoxide, hydrox3miethyl hydroperoxide, ethyl hydroperoxide, and peroxyacetic acid, J. Phys. Chem., 100(8) 3241-3247, 1996. 

Disproportionation reaction 7 might be expected to be thermoneutral in the gas phase and perhaps less so in the liquid phase where there is the possibility of hydrogen-bonding. Only for gas phase dimethyl peroxide is the prediction true, where the reaction enthalpy is —0.2 kJmoD. The liquid phase enthalpy of reaction is the incredible —61.5 kJmoD. Of course, we have expressed some doubt about the accuracy of the enthalpy of formation of methyl hydroperoxide. For teri-butyl cumyl peroxide, the prediction for thermoneutrality is in error by about 6 kJmor in the gas phase and by ca 9 kJmoD for the liquid. The enthalpy of reaction deviation from prediction increases slightly for tert-butyl peroxide — 14kJmol for the gas phase, which is virtually the same result as in the liquid phase, — 19kJmol . The reaction enthalpy is calculated to be far from neutrality for 2-fert-butylperoxy-2-methylhex-5-en-3-yne. The enthalpies of reaction are —86.1 kJmoD (g) and —91.5 kJmol (Iq). This same species showed discrepant behavior for reaction 6. Nevertheless, still assuming thermoneutrality for conversion of diethyl peroxide to ethyl hydroperoxide in reaction 7, the derived enthalpies of formation for ethyl hydroperoxide are —206 kJmoD (Iq) and —164 kJmoD (g). The liquid phase estimated value for ethyl hydroperoxide is much more reasonable than the experimentally determined value and is consistent with the other n-alkyl hydroperoxide values, either derived or accurately determined experimentally. 

O Sullivan, D. W., M. Lee, B. C. Noone, and B. G. Heikes, Henry s Law Constant Determinations for Hydrogen Peroxide, Methyl Hydroperoxide, Hydroxymethyl Hydroperoxide, Ethyl Hydroperoxide, and Peroxyacetic Acid, . /. Phys. Chem., 100, 3241-3247 (1996). 

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