Gas phase aromatic nitration by protonated fluoroalkyl nitrates

The study of gas-phase aromatic nitration by protonated alkyl nitrates has been extended from [CH3NO3] H+(1) to [CF3CH2] H+ (2) and [(CF3)2CHNO3] H+ (3). Radiolytically generated 2 and 3 efficiently promote aromatic nitration in CH4 at 760 torr, 37°C, according to an ionic mechanism whose charged reactants and intermediates have directly been detected by chemical ionization mass spectrometry. The selectivity of 2 and 3, measured by Q values of -2.6 and -2.4 respectively, as compared to -3.87 of 1, characterizes the Fluorinated cations as highly reactive and unselective gaseous electrophiles.