Ozone interaction

DeLucia, A. J., P. M. Hoque, M. G. Mustafa, and C. E. Cross. Ozone interaction with rodent lung Effect on sulfhydryls and sulfhydryl containing enzyme activities. J. Lab. ain. Med. 80 559-566, 1972. 

Hoffman, G. J., E. V. Maas, and S. L. Rawlins. Salinity-ozone interactive effects on alfalfa yield and water relations. J. Environ. Qual. 4 326-331, 1975. 

The first of the reaction steps in the amine-ozone interaction also consists of one-electron transfer from the amine to ozone, with the formation of the corresponding cation and anion-radicals. The ozone anion-radical has been revealed at low temperatures. Formation of the superoxide ion and the amine nitroxide are the understandable results of the reaction (Razumovskii and Zaikov 1984, reference therein). 

Ozone interactions with the membrane are believed to involve both critical sulfhydral groups and fatty acid residues and they may cause changes in the membrane s fluidity. 

SiddiquiMS. 1996. Chlorine-ozone interactions formation of chlorate. Water Res 30(9) 2160-2170. 

Matveev V, Peleg M, Rosen D, Tov-Alper DS, Hebestreit K, Stuta J, Platt U, Blake D, Luria M (2001) Bromine Oxide-Ozone Interaction over the Dead Sea. J Geophys Res 106 10375... 

Morrison, G.C. and Nazaroff, W.W. (2002) Ozone interactions with carpet secondary emissions of aldehydes. Environmental Science and Technology, 36/10, 2185-92. 

Ozone interactions with carpet secondary emissions of aldehydes. Environmental Science sc Technology,... 

Osawa and Doi (1992) described a surface layer of plasma-polymerized amorphous C over the transport layer to retard ozone interactions with the transport material along with increased transport material at the interface to compensate for any material that may be destroyed. The reasoning is that without a protective surface layer, the transport layer is destroyed by ozone but the surface is continually abraded so the cycling characteristics are relatively unaffected. However, in an overcoated photoreceptor the surface layer cannot be worn away and destruction of transport material by ozone results in a rising residual potential with cycling. This effect can be reduced by having a higher concentration of transport material at the interface. 

Cataldo, F. Ozone interaction with conjugated polymers. Part 1 polyacetylene. Polym. Deg. Stab. 1998, 60, 223. 

Spectroscopic studies of the interaction between ozone and organic molecules on catafyst sur ces have been very rare. Mariey et aL [S] rq>orted a Fourier transform infrared (FTIR) study of ozone interaction with phenol adsorbed on rilica and ceiia. Ozone was found to be reactive toward phenol and carboxylic acids and aldehydes were detected as posable intermediates. However, the study was carried out from 77 to 220 K, which is far from... 

The CIO radical has been directly measured since 1976 using in-situ resonance fluorescence techniques and by Menzies (1979), Anderson et al. (1980), Waters et al. (1981), De Zafra et al. (1989), and Stachnik et al. (1992) using remote sensing microwave methods. Global observations such as those provided by the MLS instrument aboard UARS (Waters et al, 1993 Figure 5.57) have improved the understanding of the behavior of CIO and the amplitude of its variations. This constitutes an important element in the study of the chlorine-ozone interaction, discussed in more detail in the next chapter. 

This type of dipolar addition reaction was introduced in chapter 3 in connection with ozonolysis (sec. 3.7.B), as well as permanganate (sec. 3.5.A),346 and osmium (sec. 3.5.B) oxidation of alkenes. Ozone is a classical example of a dipolar molecule (see canonical forms of 424 +0—O—0 and 0—O—0+). Fleming showed that the HOMO/LUMO orbitals of ozone interact with those of ethene (as shown in Figure 11.21).347... 

At this moment the ozone begins to react with the keto form and the second step is formed, whereby the rate of ozone supply becomes equal to the rate of the second reaction. The sharp transition between the two steady-state regions gives evidence that the rate of restoration of the keto-enolic equilibrium is considerably lower than the rate of ozone interaction with the keto form. 

Based on the curve in Fig. 5 one can also determine the rate constants of the ozone interaction with the two tautomeric forms. Taking into account the parameters of the first section of curve ([03] j) and by using Eq. (2), the value of the rate constant with the enolic form is foimd to be k = 2.9 X lO M-. s- and therefore the second rate constant with the keto... 

It is evident that the rate constants of ozone interaction with ketone, measured by the static method (Fig. 6) through mixing of ozone and ketone solutions at [K] [03] are higher than those found by the bubbling method (Table 6). This is not difficult to explain because in the former case the obtained values represent the total effective constant of interaction of both the enol and the keto form. 

The kinetics of ozone reactions with ketones is also determined using gas chromatographic analyses. The relative rate constants shown in Table 6, column 4 demonstrate that only acetone and methylketone possess lower reactivity than the standard. It is seen that the rate constants, calculated from the relative values and the value of the standard constant correspond to those found by the bubbling method. The main products of ozone interaction with methylethylketone are 2-hydroxymethylethylketone, diacetyl, peroxides - alkyl and hydro, acetaldehyde and AcAc. 

The probable mechanisms of ozone interaction with dihydroxybenzenes are represented in Scheme 6. 

The first studies on the reaction of ozone with paraffins have been carried out with methane, ethane, propane and butane in gas phase [2-8], It has been established that the absorption of 1 mol ozone yields 1 mol products. The analysis of the experimental data reveals two mechanisms of ozone action 1) ozone is decomposed to atomic oxygen, which initiates the oxidation process [2] mechanism - (M.1.1) and 2) ozone interacts directly with the alkane [3-5] mechanism - (M.I.2.) ... 

Williamson and Cvetanovich [17] have also registered an increase of W at low [RH] and ratios [RH]/ [O3] < 1.10 at ozonolysis of n-octane, n-pentane, 3-methylpentane and i50-pentane. They explain this fact rather by the ozone interaction with microimpurities and by the initiation of the chain reactions at low paraffins concentration. 

In order to assess the validity of the kinetic schemes we have experimentally determined the rate constants of ozone interaction with 24 paraffins of various structures. The rate constants depending on [RH] are given... 

LC is associated with H-atom cleavage mechanism and CC with ozone incorporation along the C-H bonds. LC is characterized by the ozone interaction with the C-H bond via one of its terminal atom and thus there is a possibility for free rotation around H-0 and 0-0 while in the CC it forms five member cycle with participation of five coordinated carbon. In Table 5, are summarized the alculated values of A for the two AC forms. 

The rise of the intensity of RO - singlet at the beginning has related to the disclosure of new surfaces and ozone interaction with the intermediate products of the reaction. Latter, Ref. [50] has been considered as one of the reasons for the observed course of the CL - intensity in the ozonolysis of 2, 7-dimethyloctane which has been found to be similar. 

The catalytic properties of Co in the hydrocarbon oxidation have been the subject of intensive investigations [107], It has been established that during the cumene-AcOH ozonolysis in 1 1 (v v) in the presence of Co(AcO)2 the oxidation reaction is accelerated (Fig. 17).In contrast to the noncatalysed process in the catalyzed by transition metal salts the ozonolysis is characterized by 1) absence of ozonides formation that is indicative of the absence of ozone interaction with the phenyl ring and 2) the main product is DMPC, the accumulation rate of which proportional to the concentration of Co after the 10 min. The initial rates of CHP formation do not vary with the changes in Co + but after the 15 min the rates increase with [Co ]. It can be seen from Table 9 that if we assume the ozonolysis of pure cumene as a reference then the addition of AcOH results in autoretardation of the oxidation rate and to reduction of the products yield. The ratio [IP]/[03 reaches value of 6.9. 

The ozonolysis of cumene in the presence of heterogeneous additives, which are effective in ozone decomposition [14], is of interest from two points of view (a) for elaboration of the mechanism of the ozone interaction with the heterogeneous surface and (b) to increase the oxidation selectivity. 

The rates of OZ, DMPC and CHP formation are increase with [NiO]. The ozonides are obtained from the ozone interaction with C=C bonds in the benzene ring, and the ozonolysis of the hydrocarbon part takes place via a hydrogen atom abstraction mechanism. No ozonides formation on the surface and ozonation of the alkyl part dominates in homogeneous and heterogeneous part of the reaction. The ozone is activated on the NiO surface via the formation of the surface compound Ni Oj according to the scheme oxidizes the alkyl part of cumene ... 

From the other hand the intensity at 1500 cm", which is assigned to the aromatic ring vibrations decreases in the course of the reaction. This fact confirms the ozone interaction with the benzene ring giving rise to ozonides. The latter have been identified by the occurrence of C-0 vibrations in the range of 1100-1200 cm", as well as by the iodometric titration of the oxidates. It is known that the stoichiometry of the ozone reaction with benzene is 1 3. The kinetic curves presented in Fig. 35 demonstrate a linear kinetics of ozonides formation. 

The reactions describing the ozonides formation and the ozone interaction with ROOH are included in the scheme pointed above ... 

Experimentally determined reaction rate constant of ozone interaction with -C=C- bonds in the polymer of Indian rubber latex are of the order of 2-6x10 L/mole-s. Therefore, reaction rate of the unsaturated polymer of isoprene is mainly limited by supply rate of ozone into reactor. 

In Figure 11.6, the dependences of effective correlation time for initial and cold-rolled mats on ozone oxidation time are represented. The figure shows that for the first hour there is a sharp drop of the i values and then for next 3 hours the decrease of i is very small, that is, the dynamic characteristic is stabilized. After 4 hours of oxidation, the final stage shows the initiation of correlation time decrease. Note that the initial PHB mats and the cold-rolled mats demonstrate the symbatic probe rotation when in accordance with temperature- and water-influence data the mobility of TEMPO in the cold-rolled oxidized mat is decreased relative to the initial mat after ozonolysis. Taking into account the previous characteristics of crystalline structure and ESR data in amorphous area of the PHB and PHBV films after ozone exposition [23], it can be assumed that at the first stage of oxidation the partial destruction of macromolecules occurs that leads to the increase of probe mobility. On this stage only more accessible and defect molecules take part in reaction with ozone which are situated in less dense fields of PHB. After their concentration depletion the PHB-ozone interaction is stabilized for the next 3 hours that could be treated as induction period (the plateau in the Figure 11.6) and than the oxidation... 

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