Abstract The synthesis of the title cation 3 is presented, and evidence is amassed to show that the substance contains a three-center, two-electron CHC bond. Among the evidence obtained is the'H NMR spectrum of 3, which shows a one-proton resonance for the CHC hydrogen at b-3.46 with a coupling constant JC+= 47 Hz. Upon substitution of the inside hydrogen by deuterium, the corresponding CDC bridged cation shows an upfield shift to 6 ...
