Protodetritiation reactions in aromatic substrates.

The literature on the mechanism of hydrogen exchange, on reactivity parameters in aromatic systems, and on substituent effects in aromatic systems is reviewed. The five monotritiofluoranthenes have been prepared, and their rates of protodetritiation in anhydrous trifluoro-acetic acid at 70° measured. These results have been compared with various theoretical parameters, including a dual effect equation which has been proposed for the first time. Fifteen monobromo- and mononitromonotritiofluoranthenes have been prepared, and their rates of protodetritiation determined, using a FORTRAN IV computer programme especially written for this study. An examination has been made of generalised reactivity relationships. Several specific semi-empirical equations have been derived and have been used to examine the effect of substituents upon reactivity. The dual effect equation has also been applied to substituent effects, using a theoretical substituent direct-field polar interaction.