Reactions of O2 and

58M s respectively, at 30 C and 0.1 M ionic strength. Osmate catalysis in the 104 oxidation of unsaturated organic acids involves formation or decomposition of complex intermediates in the rate-limiting step depending on the substrate structure. 

1 A/ perchloric acid, RuCb catalyzes the oxidation of primary and secondary alcohols by BrOJ. The rate-determining step does not involve Br03, but hydride abstraction by ruthenium(III) to give RCHOH intermediates takes place. The role of BrOJ is in reoxidation of the ruthenium-hydride produced in a two-electron step to give Br(III). 

Chlorate oxidation of [Fe(CN)6] follows a rate law [equation (32)] where a is dependent on acid, buffer, and the cell material, while b 

Reaction of O2 with the complex [(H20)5CrCH(CH3)2] to give [Cr(H20)6] and acetone proceeds by a chain mechanism initiated by chromium-carbon bond cleavage with a rate of 1.74 x 10 s at 25°C and 1.0 M ionic strength. Inhibition studies suggest the organic radicals (CH3)2CH and (CH3)2CH02 are chain intermediates involved in the reaction 

Autoxidation of a,j8,y,5-tetraphenylporphorin-chromium(II), [TPPCr(II)], in tolulene solution proceeds in two stages with intermediate formation of a jii -oxo-chromium(III) complex [TPPCr(III)]20 prior to the chromium(II) product [TPPCr(IV)0]. Reaction of [TPPCrO] with [TPPCr(II)] yields the chromium (III) dimer. A pH-dependent equilibrium involving intramolecular electron transfer between Mn(II)-02 and Mn(III)-O2 is observed in the reaction of a tetrasulfonated-phthalocyanine manganese(II) complex with O2. The superoxide species is found only at pH 11.5-13.5. A manganese(II)-02 complex is also required to explain the absence of spectroscopic characteristics for both (II) and (III) oxidation states of manganese in the reaction of a trivalent pentadentate Schiff base derivative with O2. 

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Relatively detailed study has been done for the reaction pathways over Au/Ti02 catalysts mainly because of simplicity in catalytic material components. The rate of PO formation at temperatures around 323 K does not depend on the partial pressure of C3H6 up to 20vol% and then decreases with an increase, while it increases monotonously with the partial pressure of O2 and H2 [57]. A kinetic isotope effect of H2 and D2 was also observed [63]. These rate dependencies indicate that active oxygen species are formed by the reaction of O2 and H2 and that this reaction is rate-determining [57,63,64]. 

In accord with an approach originally outlined by Jortner and coworkers,41 42 the influence of changing AG° upon the 180 KIE has been modeled using a saddle point approximation.43 At this stage, the experimental variations in 180 KIEs for reactions of O2 and O2" are yet to be determined. The vibronic model of Hammes-Schiffer, which has been used to model proton-coupled electron transfer in accord with a Bom-Oppenheimer separation of timescales, may also be applicable here.44 The objective is to account for the change in 0—0 vibrational frequency together with potential contributions from overlap of vibrationally excited states. The overlap factors involving these states are expected to become more important as AG° deviates from 0 kcal mol 1,39... 

This system s behavior is represented by a mechanism that combines the reactions associated with irradiating NO2 and C3H6 and with the mechanism for oxidizing C3H6 by O3. The process also includes the reactions of O2 and NO2 with all of the free radicals and intermediates with... 

The etching of Cu metal in solutions of 500 1 DHF is linear with the concentration of dissolved Oj. Etch rates from 2 to 16 nm/min are controllable with O2 partial pressures of 0.05 to 0.65 atm ( 2.5 to 33 ppm O2). The linear behavior indicates that the reaction is limited either by the transport of O2 to the surface or the reaction of O2 and Cu at the surface to form CuO. This DHF 02 chemistry shows great promise for post Cu CMP cleans. 

Several workers have observed a relationship between the the enthalpy of formation of an oxide and its activity in oxidation reactions. Kiyoura [16] has reported the occurrence of such a relationship in the (closely similar) exchange reactions of O2 and of COj on metal oxides of the fourtii period. Moro-Oka et al. [17] correlated the catalytic properties of several oxides in the oxidation of various C2 to C4 hydrocarbons, with the energy released on formation of the solid concerned. 

With the rate, reactant concentrations, and reaction orders known, the sole remaining unknown in the rate law is the rate constant, k. The rate constant is specific for a particular reaction at a particular temperature. The experiments with the reaction of O2 and NO were run at the same temperature, so we can use data from any to solve for k. From experiment I in Table 16.2, for instance, we obtain... 

On the positive side, the heterogeneous catalysis of the oxidation of SO2 is used to advantage in the manufacture of sulfuric acid, where the reaction of O2 and SO2 to form SO3 is catalyzed by a solid mixture of platinum and vanadium(V) oxide. 

The rate constants for reactions of O2 and HOO- have been collected by Bielski... 

Table 8.2 Completed data for the reaction of O2 and C3H8 (propane) ...

EXAMPLE 22.5 Balancing of and Assigning Oxidation States to Sulfur Reactions Write a balanced equation for the reaction of O2 and H28 to form elemental 8 (in the form of 8g). Identify the change of the oxidation state for 8. SOLUTION ... 

Recently, a novel approach has been demonstrated for detecting the small temperature changes accompanying the adsorption of gases on metal surfaces. In a pioneering investigation the heat evolution in the adsorption and subsequent reaction of O2 and H2 to form water on a thin Pt-layer evaporated on a SFM bimetallic cantilever has been studied [94GIM]. 

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