Exchange of Aromatic Hydrocarbons with Deuterium

Note reiteration of these steps can account for the formation of molecules containing up to six deuterium atoms as initial products. 

Measurements of kinetic parameters for exchange are sparse. Activation energies on platinum and palladium films were much higher than for addition, and on the latter the order in deuterium was negative (-0.5) for exchange but positive (0.8) for addition. Orders of zero for both reactants have been recorded for a number of metal films.  

Note all steps are shown as reversible, so that the mechanism could also describe the exchange however the loss of resonance energy on addition of the first atom probably makes its reversal very unlikely. The mechanism also describes the formation of cyclohexene (Section 10.27) and the dehydrogenation 

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