Bifunctional catalyst, double catalytic

It now remains to place the concept of an ester as an active species into a wider chemical context, with special reference to polymerisation catalysts. Sinn and Patat [39] have emphasised the distinction between monofunctional and bifunctional catalytic systems and this distinction is obviously and necessarily related to the idea, explained above, that there is a difference in kind between polarised molecules and the ions which can be formed from them. Whereas the carbonium and other cations as reactive species are monofunctional, the esters evidently belong to the class of bifunctional catalysts their mode of action - the addition of their constituent parts across a double bond - is, in modern terminology, an insertion reaction. In this context, we must note the important... 

Double Catalytic Activation Using a Bifunctional Catalyst with Both Acid and Base on Solid Surfaces... 

Catalytic Hydrogenation of Carboxylic Acid Derivatives Containing C=0 Double Bonds with Bifunctional Molecular Catalysts... 

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