Reactions of naphthalene in N 2 O 5 NO 3 NO 2  air mixtures

The reactions of naphthalene in N 2 O 5 NO 3 NO 2 N 2 O 2 reactant mixtures have been investigated over the temperature range 272–297 K at ca. 745 torr total pressure and at 272 K and ca. 65 torr total pressure using long pathlength Fourier transform infrared absorption spectroscopy. 2,3‐Dimethyl‐2‐butene was added to the reactant mixtures at 272 K to rapidly scavenge the NO 3 radicals both initially present in the added N 2 O 5 and formed from the thermal decomposition of N 2 O 5 during the reactions. The data obtained in the presence and absence of added 2,3‐dimethyl‐2‐butene showed that napthalene undergoes initial reaction with the NO 3 radical to form an NO 3 ‐naphthalene adduct, which either rapidly decomposes back to the reactants (at a rate of ca. 5 × 10 5 s −1 at 298 K) or reacts exclusively with NO 2 to form products. When NO 3 radicals, N 2 O 5 and NO 2 are in equilibrium, this overall process is kinetically equivalent to reaction of naphthalene with N 2 O 5 , and previous kinetic and product studies have indeed assumed the reactions of naphthalene and alkyl‐substituted naphthalenes in N 2 O 5 NO 3 NO 2 air mixtures to be with N 2 O 5 , and not with NO 3 radicals.