Mechanistic inadequacy

All subsequent models for selectivity behaviour are, in some way or other, disguised in equation 5.29 the reason for this being that deviations from theoretical ideal behaviour as expressed through the values of resin phase activity coefficients, or by the interaction energetics required by a mechanistic model, are equivalent statements. In other words, the fundamental causal factors which determine selectivity plus any inadequacies in our understanding are all reflected in the adopted model whether thermodynamic or molecular. 

The inadequacies outlined in the preceding paragraphs prompt a widening of the mechanistic considerations to include pathways to photo-assisted conversions of alcohols based on photoinitiated homolytic bond cleavage with free-radical intermediates, e.g. as in... 

The first attempt to use the simultaneous solution approach for ammonia synthesis over iron catalysts gave estimated reaction rates several orders of magnitude lower than those found in practice. This is discussed in the chapter on iron kinetics, but can be attributed to inadequacies in the underlying database, in particular the use of low-coverage adsorption data. The closest approach to a mechanistically acceptable model has come from studies into ammonia decomposition on platinum. " The characteristics of this reaction over many transition metals are ... 

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