More than 100 years after the cyclopentadienyl anion appeared in the literature, the first cyclopentadienyl cation, the pentamethyl derivative C5Me5+, has now been prepared in a single step as the tetrakis(pentafluorophenyl)borate salt. This material is crystalline and stable at room temperature for weeks. The crystal structure of C5Me5+ (see picture) reveals localized bonding.
No takes yet. Share an insight, caveat, or question.
Lambert et al. (2002) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: