Chemistry of the Heterotriquinanes and Heterotriquinacenes

Abstract

Triquinanes are tricyclic hydrocarbons that have fused cyclopentane rings. Although there are linear and angular triquinanes that are doubly fused, this Account focuses exclusively on the ‘triquinacane’, or triply fused structure with a heteroatom (nitrogen or oxygen) on the C 3v symmetry axis. Azatriquinane- and oxatriquinane-based species tend to show remarkable and often unexpected chemistry, and have variously comprised the most basic trialkyl amine, a superbasic proton chelate, trigonal pyramidal ligand platforms, novel calixiform hosts, aromatic hemispheres of hetero-C20 fullerenes, cocrystallizing agents for eliminating rotational disorder in fullerene crystals, the first water-stable, chromatographable trialkyloxonium species, the first isolable allylic oxonium species, world-record C–O bond lengths, rapid SN2 reaction at a tertiary center, and R4O2+ (oxadionium) species.1 Introduction2 Azatriquinane3 Azatriquinacene4 Aromatic Azatriquinacene-Based Systems5 Oxatriquinane6 Tetravalent Oxygen7 Oxatriquinacene8 The Future

Deciphering the chemical bonding of the trivalent oxygen atom in oxygen doped graphene

“…These ndings have encouraged the exploration of a plethora of new analogous oxonium ions. [6][7][8][9][10][11][12][13] However, it should be emphasized that, to the best of our knowledge, in all the molecules containing trivalent oxygen, O is positively charged and tetrahedral due to the sp 3 hybridization. There are only three exceptions to this rule: Al 3 O, Tl 3 O and Ga 3 O.…”