Triangular reaction

A number of other unimolecular cases have been solved, such as parallel reactions, those with more general initial conditions, triangular reactions, unimolecular decomposition through a number of internal states, and those with time dependent rate constants.67 Ishida9 has, in fact, used this last case to approximate the solutions of the more complicated bimolecular... 

Figure 10-11. The structure of the active site in ascorbate oxidase. The enzyme contains four copper centres. Three of these form a triangular reaction site. Why are four copper ions needed How does the substrate bind ...

If C and D are the same, it is a triangular reaction, e.g., in the silver-catalyzed partial oxidation of ethylene. By setting k equal to zero, we get a consecutive reaction ... 

A.G.Fredrickson, Stochastic Triangular Reactions, Chemical Engineering Science, 21,687-691(1966). 

In the conditions used, all the catalysts were active for the combustion of ethane, producing conversions from 1-5 % at 573 K up to 40 % at 648 K. The only detected products were CO2, H2O and small amounts of ethene, that is consistent with a triangular reaction scheme involving parallel formation of CO2 and ethene and the consecutive combustion of ethene. In separate measurements of CO oxidation on these catalysts, made in a Fl lR cell [26], CO was transformed conipletely into CO2 at tenoperatures as low as 573 K This would e q)lain the absence of CO among the reaction products of ethane oxidation, carried out here at hi er tenq>eratures. Fig. 3 shows the variation of areal rates of ethane oxidation over the LKx and NKx catalysts with terrqrerature. In all cases, ethane conversion increased with increasing... 

Network analysis can be simplified for well known classes of complex reactions such as parallel reactions, series (or consecutive) reactions, independent reactions, series-parallel reactions, triangular reactions, and the so-called Denbigh reaction. These reactions may be represented as follows ... 

The rates of formation and further reaction of possible intermediates in multi-step reactions may be very different. If we consider a triangular reaction and know that both A —> C and B —> C takes place, the question if (a) a direct A —> C reaction or the A —> B —> C stepwise process prevails, or (6) possibly both processes take place, can be clarified by reacting a mixture of A - - B, with one component labelled (denoted by ). If A + B is reacted to obtain C, the appearance of radioactivity in B gives evidence that the stepwise process is possible. This will be illustrated in the next example (Scheme lA and IB). 

Figure 5.1 Simplified triangular reaction scheme of wet oxidation...

In the above expression, [TOC j is the asymptotic residual organic carbon, which cannot be oxidized (Rcl) further. Agreement between the experimental data for combined thermolysis, catalytic, and non-catalytic WO and the model prediction is shown in Figure 5.5. From this plot one can conclude that the oxidation progress is terminated once the catalyst is deactivated due to the adsorption of carbonaceous intermediates on its surface. However, for practical design purposes one should use the lump kinetic approach based on the triangular reaction scheme such as depicted in Figure 5.1. It is believed that the rate laws can be expressed mostly by a simple power function. 

It is obvious that ORR is obeyed. Thus, in case of chemical reactions, linear and non-linear flux equations similar to the case of electro-kinetic phenomena are predicted and ORR between first-order cross-coefficients is also obeyed. However, experimental studies so far have not been made, although triangular reaction of the above type for isomerisation of Aa - pentenoic acid has been investigated from a different viewpoint [25]. 

This triangular reaction network, discovered by Haag and Pines and further studied by Lago and Haag, provides a recent but already classical example of a successful analysis of a network of first-order reversible reactions. The network is ... 

Figure 26 describes a triangular reaction network for butane oxidation (Buchanan and Sundaresan, 1986). The reactions for each pathway can be expressed as... 

As an example we consider the triangular reaction, discussed above, in a stationary state. Let c i = 1, 2, 3) be the stationary concentrations so that... 

Since a is not minimized in a stationary state far from equilibrium dai A no longer negative for a natural process, but Glaiisdorff and Prigogine have shown that for a rather wide class of systems it still holds that dxo 0. To see this for a system of the kind we have considered here, we consider again the triangular reaction and using... 

Reactions were carried out under a fluorescent lamp using a 200 ml triangular reaction vessel contianing 1.57 mmol of a-iodocyclododecanone. 2-Hydroxycyclododecanone(llc) was obtained. 

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