Reaction of NO with

Tetraneopentyltitanium and ((CH2)2SiCH2)4Ti [33948-28-6] react with nitric oxide to yield compounds having R groups bonded ia two different ways, as shown by nmr (214). The reactions of NO with R TiCl and R2TiCl2 yield similar products that have Cl iastead of the —ONRNO substituent. 

The principal method used for measuring NO2 is also based on chemiluminescence (Fig. 14-3) (5). NO2 concentrations are determined indirectly from the difference between the NO and NO (NO -I- NO2) concentrations in the atmosphere. These concentrations are determined by measuring the tight emitted from the chemiluminescent reaction of NO with 03 (similar to the reaction of O3 with ethylene noted for the measurement of O3), except that O3 is supplied at a high constant concentration, and the light output is proportional to the concentration of NO present in the ambient air stream. 

Fig. 14-3. NOj chemiluminescent detection principle based on the reaction of NO with O3.

Nitric oxide may induce deleterious effects when airway epithelial or immunological cells are exposed to mineral particles (asbestos, quartz). These particles also stimulate cells to produce NO in large quantities, but pulmonary cells are unable to destroy these particles, and a non-physiologically excess production of NO results, perhaps causing tissue damage due to a reaction of NO with cellular macromolecules. 

This S-nitroso group is in equilibrium with other S-nitroso compounds formed by reaction of NO with small-molecule thiols such as free cysteine or glutathione (an isoglutamylcysteinylglycine tripeptide) ... 

The corresponding nitrites, MNO2, can be prepared by thermal decomposition of MNO3 as indicated above or by reaction of NO with the hydroxide ... 

As already shown in Figure 6.3b the system exhibits remarkable electrophilic promotional behaviour with p values up to 20.64 This is also shown in Fig. 8.60 which depicts a galvanostatic transient. Application of a negative current between the Pt catalyst-working electrode and the Au counter electrode causes a sharp increase in all reaction rates. In the new steady state of the catalyst (achieved within lhr of current application) the catalytic rate increase of C02 and N2 production is about 700%, while lesser enhancement (250-400%) is observed in the rates of CO and N20 production. The appearance of rate maxima immediately after current application can be attributed to the reaction of NO with previously deposited carbon.64... 

The intrinsic kinetics of the reactions taking place in the scrubber, i.e. the reaction of NO with the iron chelate forming an iron nitrosyl complex (eq. 1) and the undesired oxidation reaction of the iron chelate (xanpla (eq. 2) wae deteimined in dedicated stirred cell contactors. Typical process conditions were T = 25-55 °C [Fe"(EDTA) "] = 1-100 mol/m [NO] = 1-1000 ppm pH = 5-8 and an oxygen level ranging between 1 and 20 vol%. 

C15-0003. The following mechanism has been proposed for the reaction of NO with H2 ... 

C15-0045. The reaction of NO with CI2 is 2 NO + CI2 2 NOCl Use reactant molecules to write appropriate elementary reactions that satisfy the following criteria (a) a unimolecular decomposition that generates Cl (b) a bimolecular collision in which a Cl atom is transferred between reactants and (c) a termolecular collision leading to the observed products. 

C15-0080. The reaction of NO with O2 to give NO2 is an important process in the formation of smog in Los Angeles 2 NO + O2 2 NO2 Experiments show that this reaction is third order overall. 

It is significant that in the absence of O2 (solid points in Figure 4) almost no radicals were formed the amount reported is close to the detection limit of the instrument. In one sense, this observation provides an explanation for the positive effect that O, has on the rate of reaction between NO and CH4 [3,4] i.c., O2 enhances CH,- radical formation. However, the results also indicate that NO itself is not very effective in generating active sites which are responsible for CH,- radical production. This means that the reaction of NO with CH4, in the absence of added O, may occur via a nonradical pathway. 

The values of the rate constants are estimated by fitting equations 1.4a and 1.4b to the concentration versus time data. It should be noted that there are kinetic models that are more complex and integration of the rate equations can only be done numerically. We shall see such models in Chapter 6. An example is given next. Consider the gas phase reaction of NO with 02 (Bellman et al. 1967) ... 

Bellman et al. (1967) have considered the estimation of the two rate constants k and k2 in the Bodenstein-Linder model for the homogeneous gas phase reaction of NO with 02 ... 

Table 6.1 Data for the Homogeneous Gas Phase Reaction of NO with 02.

A different picture emerged from the comparison of IR measurements in static and flow conditions. The IR spectra recorded in the temperature range of 423-823 K during the catalytic reaction of NO with the CuZSM-5 are collected in Figure 2.24. The spectra are dominated by the broad and intense absorption bands centered at 1470, 1630 and 2224 cm-1, assigned to N02-related species such as surface nitrates N03 [77,78],... 

A convenient preparative method for conjugated nitroalkenes has been developed based on the reaction of nitrogen oxides. Nitric oxide (NO) is commercially available and used in the industry for the mass production of nitric acid. Nitric oxide is currently one of the most studied molecules in the fields of biochemistry, medicine, and environmental science.47 Thus, the reaction of NO with alkenes under aerobic conditions is of a renewed importance.48... 

Fig. 19 UHF-MP2 ab initio calculation of the reaction of NO with alkyl chlorides. Energetic and geometric characteristics of the reactan product and transition state systems as functions of steric hindrance. 

Chemiluminescence is believed to arise from the 2Bj and the 2B2 electronic states, as discussed above for the reaction of NO with ozone [17]. The primary emission is in a continuum in the range =400-1400 nm, with a maximum at =615 nm at 1 torr. This emission is significantly blue-shifted with respect to chemiluminescence in the NO + 03 reaction (Xmax = 1200 nm), as shown in Figure 2, owing to the greater exothermicity available to excite the N02 product [52], At pressures above approximately 1 torr of 02, the chemiluminescence reaction becomes independent of pressure with a second-order rate coefficient of 6.4 X 10 17 cm3 molec-1 s-1. At lower pressures, however, this rate constant decreases and then levels off at a minimum of 4.2 X 1(T18 cm3 molec-1 s-1 near 1 mtorr, and the emission maximum blue shifts to =560 nm [52], These results are consistent with the above mechanism in which the fractional contribution of (N02 ) to the emission spectrum increases as the pressure is decreased, therefore decreasing the rate at which (N02 ) is deactivated to form N02. Additionally, the radiative lifetime and emission spectrum of excited-state N02 vary with pressure, as discussed above for the NO + 03 reaction [19-22],... 

The most important physiological nitrogen substrate of peroxidases is undoubtedly nitric oxide. In 1996, Ishiropoulos et al. [252] suggested that nitric oxide is able to interact with HRP Compounds I and II. Glover et al. [253] measured the rate constants for the reactions of NO with HRP Compounds I and II (Table 22.2) and proposed that these reactions may occur in in vivo inflammatory processes. The interaction of NO with peroxidases may proceed by two ways through the NO one-electron oxidation or the formation of peroxidase NO complexes. One-electron oxidation of nitric oxide will yield nitrosonium cation NO+ [253,254], which is extremely unstable and rapidly hydrolyzed to nitrite. On the other hand, in the presence of high concentrations of nitric oxide and the competitor ligand Cl, the formation of peroxidase NO complexes becomes more favorable. It has been shown [255]... 

As mentioned earlier, ascorbate and ubihydroquinone regenerate a-tocopherol contained in a LDL particle and by this may enhance its antioxidant activity. Stocker and his coworkers [123] suggest that this role of ubihydroquinone is especially important. However, it is questionable because ubihydroquinone content in LDL is very small and only 50% to 60% of LDL particles contain a molecule of ubihydroquinone. Moreover, there is another apparently much more effective co-antioxidant of a-tocopherol in LDL particles, namely, nitric oxide [125], It has been already mentioned that nitric oxide exhibits both antioxidant and prooxidant effects depending on the 02 /NO ratio [42]. It is important that NO concentrates up to 25-fold in lipid membranes and LDL compartments due to the high lipid partition coefficient, charge neutrality, and small molecular radius [126,127]. Because of this, the value of 02 /N0 ratio should be very small, and the antioxidant effect of NO must exceed the prooxidant effect of peroxynitrite. As the rate constants for the recombination reaction of NO with peroxyl radicals are close to diffusion limit (about 109 1 mol 1 s 1 [125]), NO will inhibit both Reactions (7) and (8) and by that spare a-tocopherol in LDL oxidation. 

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