Multiplet mechanisms doublet

The first mechanism proposed for the newly discovered hydrogenolysis of cyclopentane was the doublet mechanism (104), in line with the general multiplet theory of Balandin (105). According to this mechanism, cyclopentane is physically adsorbed on two metal atoms, and stands perpendicular to the surface in the vicinity of physically adsorbed hydrogen atoms (Fig. la). This mechanism, however, does not explain why cyclopentanes are hydro-genolyzed on platinum while cyclohexanes and paraffins are not. 

This classification is important not only for kinetics and for the equilibrium of the heterogeneous catalytic reactions with a doublet mechanism, but for the equilibrium of homogeneous catalytic and non-catalytic reactions as well, because the equilibrium does not depend on the mechanism of the reaction. It is interesting to note that the cyclic activated 4- and 6-complexes, postulated by Syrkin 355), are nothing but doublet and triplet index groups, and consequently the multiplet classification must be proper for them as well hence it can also be applied to the kinetics of catalytic reactions that are not heterogeneous. 

Let us discuss the first of these mechanisms. In mixed catalysts the activity is concentrated at the interface of solid phases. Much experimental data pointing to this phenomenon have been obtained in the author s laboratory (see Section II,G). Therefore, it is natural to consider that in the catalytically active site some atoms of the reacting molecule are attracted by the multiplet atoms of one chemical nature, while other atoms of the molecule are attracted by those of a different nature. As an example of the relative arrangement of the atoms of the reacting molecule and binary catalyst one can cite the model of doublet hydrogenation (and dehydrogenation). For further details see Fig. 6. In Fig. 6 the lower atom of the catalyst differs from others (in this case in its chemical nature). 

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