“…For example, the gas-phase basicities (GB) and proton affinities (PA) of 1,3,5-cycloheptatriene [27] and 6-methylfulvene [28] have been determined, adding to the corresponding data of toluene and 2,5-norbornadiene published previously [10, 29,30]. Furthermore, various recent experimental and computational work, including mostly the homologues and analogues of C7H9 + ions, including benzenium [31,32] and the xylenium ions [33][34][35] and protonated alkylcycloheptatrienes [36] have provided much insight into the parameters governing the unimolecular isomerization and fragmentation of these evenelectron carbocations.…”