1,4,5,8-Tetramethylnaphthalene dication and related radical cations

Stable Ion Studies of Protonation and Oxidation of Polycyclic Arenes,

“…29 The persistent dication of 1,4,5,8-tetramethylnaphthalene 72 2+ has also been generated (Figure 60). 72 The isomeric 1,2,3,4-tetramethylnaphthalene gave a dication/RC equilibrium; similar results were found with hexahydropyrene. 72 A series of persistent dications of meso-substituted anthracenes has been reported by Olah and Singh.…”

“…72 The isomeric 1,2,3,4-tetramethylnaphthalene gave a dication/RC equilibrium; similar results were found with hexahydropyrene. 72 A series of persistent dications of meso-substituted anthracenes has been reported by Olah and Singh. 32 The observed total carbon deshielding in these systems are between 208.4 and 212.9 ppm/e.…”

Carbocations in Superacid Systems

“…[482][483][484][485][486][487][488][489][490][491][492][493][494][495] In strong acid solutions, monopositive radical ions and/or dipositive ions, also known as oxidation dications, have been reported. [482][483][484][485][486][487][488][489][490][491][492][493][494][495] In strong acid solutions, monopositive radical ions and/or dipositive ions, also known as oxidation dications, have been reported.…”

“…Although benzene does not undergo two-electron oxidation reactions upon treatment with SbF 5 -SO 2 ClF, but gives instead the benzenium ion 88 by protonation 253 (due to HF impurity in the system), naphthalene has been reported to give the corresponding radical monocation upon treatment with SbF 5 -SO 2 ClF at À78 C. 494,495 However, the presence of methyl substituents on the ring lowers the ionization potential to a point that stable carbodications can be formed. Thus, the tetramethyl-and octamethylnaphthalene dications 232 and 233 have been prepared 495 from the corresponding arenes.…”

First Examples of Fluorinated and Chlorinated Polycyclic Aromatic Hydrocarbon (PAH) Dications from Benzo[a]pyrene, Pyrene, and Their Alkyl-Substituted Derivatives

“…In comparison, the field of stable dication chemistry of alternant and nonalternant PAHs and bridged annulenes is relatively less extensive. Following initial feasibility studies using early, low-field 1 H NMR by Brouwer, many of the subsequent investigations were reported by Olah and associates. − More recent examples were provided by Michl, Laali, − Müllen, , and their associates; the topic has been reviewed …”