"IPSO" AROMATIC ALKYLATION IN THE GAS PHASE. INTERMEDIACY AND STRUCTURE GASEOUS HEPTAALKYLBENZENIUM IONS

Article abstract of DOI:10.1021/ja00294a015

The structure of heptaalkylbenzenium ions has been investigated in the gas phase with complementary techniques, i. e., chemical ionization mass spectrometry, alkylation of hexaalkylbenzenes by radiolytically generated cations, and collisianally induced dissociation mass spectrometry.The results allow us to assign the ?-complex ( Wheland intermedisate ) structure to the free, gaseous heptaalkylbenzenium ions, in agreement with the established structure of their salts in solution and in the solid state.The heptaalkylbenzenium ions represent the charged intermediates of the gas-phase "ipso"-substitution reactions, whose occurence has been demonstrated and whose mechanism is briefly discussed.