aromatic chemistry - j hepworth, d waring, m waring (rsc, 2002) ww

... and 1, 4- are sometimes replaced by the terms ortho-, meta- and para- (abbreviated to 0-, m- and p-, respectively) (see 6; borth0 24 and 25). You are advised to become familiar ... is -1 20 kJ mol-I and that of cyclohexa-1,3-diene with two double bonds is almost twice that at -2 32 kJ mol I. Cyclohexatriene, if it existed, would be expected to have an enthalpy of hydrogenation ... benzene and its derivatives is rather than addition. Indeed, electrophilic sub- stitution in aromatic systems is one of the most important reactions in chemistry and has many commercial applications....