Thermal dissociative reactions

On the other hand, both reduction and thermal-dissociation reactions will result in an increase in weight (equivalent to the solute deposited) and a slight increase in dimensions which will depend on the average composition of the diffused layer. 

Some interesting conclusions can be drawn by plotting log against temperature for thermal dissociation reactions of the type M + CI2 MClj (Mis any given metal). (See Fig. 12.18) . 

Also thermal dissociation reactions, such as dissociation of hydrogen,... 

The literature [11] has shown that, in water, hydrosulfite is converted to bisulfite (Equation 13.1). On the other hand, Wan [18] has clearly shown that the following thermal dissociation reaction does not occur (Equation 13.3) in aqueous solutions of sodium bisulfite ... 

We may say that the work which has been done after the war has somewhat changed our views about the physical grounds of chemical kinetics. We have learned that the old a posteriori experimental evidence of the collision theory has proved to be unsafe, being grounded upon ill-defined quantities, such as the diameter to be used in the rate expressions. This has been particu-lary evident for thermal dissociation reactions, where the knowledge of the activation energy makes possible a real test. 

Thermal dissociation reactions are not important in plasma systems because of the low gas temperature. Dissociation of molecules is induced by energetic electron bombardment instead. In contrast, thermal dissociation is a major mechanism for radical generation in thermal CVD systems [20]. 

The thermal decomposition of copper (II) tartrate, Cu(C4H406)- 3H20, and cobalt (II) tartrate, Co C4H406)-2.5H20, were investigated by use of TG, DTG, DTA, and MS techniques by Schmid and Felsche (69). In an argon atmosphere, the thermal dissociation reactions of both these compounds can be described by the equations... 

To apply the results of the chemical activation and the thermal dissociation analysis for comparison to literature or experimental data (when available) it is necessary to construct an elementary chemical reaction mechanism. The mechanism includes all the reactions involved in the chemical activation process, including stabilizations and reactions for thermal dissociation of the stabilized species. The reactions are reversible, so that we implicitly take into account some of the thermal dissociation reactions as the reverse of the forwards (chemically activated) reactions. For example, the dissociation of DBFOO to DBF + O2 is included as being the reverse reaction of DBF + O2 o DBFOO. ThermKin is used to determine the elementary reaction rate coefficients and express the rate coefficients in Arrhenius forms. 

Reaction kinetics parameters were determined as averages from three replicate runs. The most reliable kinetics pararaeteij s (Table 2) were obtained with the isocyanate peak (2256 cm" ) since it was isolated from overlapping side peaks and had a readily defined baseline. In fact, the kinetics parameters obtained with the isocyanate peak for the thermal dissociation reaction agree well with those of Kordomenos et. al. as shown in Table 2. 

Fig. 12. Fractional conversion curve for the thermal dissociation reaction of the blocked isocyanate.

This dissociation energy difference means that the activation energy for the thermal dissociation reaction should be 1.15 kcal/mol greater for the C—D... 

Energy-minimized conformations from molecular mechanics are useful to estimate the energetics of metal-ligand bond dissociation. A plausible thermal dissociation reaction for generic zero-valent metal carbonyl complexes that corresponds to the onset of the glass transition is... 

Another example of a complex prepared by a thermal dissociation reaction is the preparation of cis-[Cr(en)2Cl2] by heating [Cr(en)3]Cl3 ... 

Two experimental techniques have been much used to study the preparation of complexes by the thermal dissociation reactions. 

Figure 6. Fall-off curves for the thermal dissociation reaction N2O5 -h N2 - NO2 + NO3 + N2 (experiments O = Connell and Johnston, 1979 = Viggiano et al. 1981 theoretical analysis = full lines, from Malko and Troe, 1981).

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