Effect of isotopic substitution upon the gas phase and solution electron affinities of nitrobenzene

Relative Solution Electron Affinities of Selectively Deuteriated Pyrenes: Correlations between Voltammetric, Electron Paramagnetic Resonance, and Semiempirical PM3 Data

“…MS (m/ z): M + ) 208.1196 (C 16 H 4 D 6 requires 208.1159). 1,2,3,6,7,5,9,10-tetrahydropyrene (2e). 4,5,9,10-Tetrahydropyrene (2a) (10.0 g; 48.4 mmol) was deuteriated 3 times with PPA-d (90 g) in the manner described for pyrene.…”

“…On the benzylic positions approximately 10% deuterium is incorporated. IR 1, 3,6,5,9,. Compound 2e (2.06 g; 9.7 mmol) was treated with Br 2 (3.5 g; 22 mmol) and FeCl 3 ‚6H 2 O (270 mg; 1.0 mmol) in water (75 mL).…”

“…IR (KBr): 2915, 2880, 2825, 2245, 1426, 1411, 1294, 908 cm -1 . MS (m/z): M + ) 210.1379 (C 16 D 10 H 4 requires 210.1347).1,3,6,. Compound 2c (580 mg; 2.75 mmol) was dehydrogenated with DDQ (1.36 g; 6.0 mmol) in refluxing toluene as described for the preparation of 1e.…”

Nucleophilic substitution of the nitro group, fluorine and chlorine in aromatic compounds

“…Scheme 1 Indeed, in the reactions of pentafluoronitrobenzene with nucleophilic reagents (hard N-and O-or soft S-anions) it is the fluorine atom in position 2 or 4 that is usually replaced whereas the nitro group remains unaffected. 33,34 It is therefore more likely that this reaction occurs according to the route b where the additionally activated nitro group in the intermediate compounds 19 and 20 is replaced by the fluorine ion resulting in perfluoro-tertbutylbenzene (17) or perfluorotoluene (18). 30,35 Supporting evidence in favour of this route can be derived from the yields of compounds 17 and 18: the yield of a direct substitution product according to the route a is smaller for the more nucleophilic perfluorobutyl anion.…”

“…First of all, it is worth comparing the activity series of the nitro group, fluorine and chlorine for those cases where substitution occurs according to the S N Ar mechanism with s-complex for-EWG = NO2 (14), CF3 (18), CN (61); R = Me (63a), Et (63b). Table 5.…”