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1950595 
Journal Article 
THERMODYNAMIC NITRATION RATES OF AROMATIC-COMPOUNDS .3. NITRATION OF AROMATIC-COMPOUNDS IN CONCENTRATED AQUEOUS TRIFLUOROMETHANESULFONIC ACID 
Marziano, NC; Tortato, C; Sampoli, M 
1991 
Yes 
Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry
ISSN: 0300-9580 
3 
423-429 
WOS:A1991FC25500025 
The kinetics of nitration of mesitylene, toluene, benzene, bromobenzene and methyl phenyl sulphone, reacting as free bases in the range 50-100 wt% CF3SO3H are reported. The rates, related both to the stoichiometric concentration of nitric acid (rate = k2obs[Ar] [HNO3]) and to the effective concentration of electrophilic species (rate = k2-degrees[Ar] [NO2+]) have been determined. Compared with k2obs, which exhibits a large solvent effect, the true nitration rates (k2-degrees) were found to be almost independent of medium acidity and, for a given compound, rather similar in different acids. The k2-degrees values were also found to be linearly related to the rate constants for nitration in the gas phase.



The rates of reaction for methyl phenyl sulphone in 80-100 wt% acid were found to be lower in CF3SO3H than in H2SO4 by a factor of 8. A similar rate profile is observed, however, with an increase up to 90% acid and a decrease between 90 and 100%. The dependence of the rate profiles upon acidity and temperature in very concentrated acid solutions is discussed.