Benzylidene fluorene ozonolysis under chemiluminescence mimetic conditions in homegeneous and micellar media I: Kinetic law as a function of hammett's σ constants and quenching by the leaving moiety

Abstract

A series of 9-(p-substituted) benzylidene fluorenes (p-nitro, p-cyano, p-chloro, p-bromo, p-H, p-methyl, p-methoxy, p-methoxy-m-methyl and p-dimethylamino) was synthesized and the rates of fluorenone production on oxidation with ozone were followed fluorimetrically (apparent rates) and spectrophotometrically (true rates). The rates were plotted against Hammett's σ constants and any quenching effect of the leaving moiety on fluorenone at the moment of their production was illustrated as deviation from the plot of the apparent rates. The above effect was intensified in micellar media as a result of a more rigid confinement of the two species inside the micelle, supporting an earlier suggestion that, in chemiluminescence, even a small degree of quenching of the primary emitter by the leaving moiety can be very effective as a result of their inherent proximity at the moment of their production.