Nitration by dinitrogen pentoxide

Ingold et al." showed that rates of nitration by benzoyl nitrate in carbon tetrachloride were depressed by the addition of benzoic anhydride. Thus addition of 0.035 M of the anhydride to a solution 2.36 M in benzene and 0.030 M in nitrate decreased the first-order rate coefficient from 44x 10-4 to 20xl0-4. This is consistent with nitration by dinitrogen pentoxide formed via equilibrium (37), viz. 

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