Multiply charged aromatic cations : The heptalenium dication

Abstract

A logical route to multiply charged aromatic cations involves the successive fusion of monopositively charged seven-membered rings, beginning with the tropylium cation C₇H₇⁺. Ab initio molecular electronic structure theory has been applied to the second member of the series, the heptalenium dication C₁₂H₁₀²⁺, which is predicted to be bound relative to selected possible fragmentation partners. By suitable synthetic procedures, it should be possible to prepare both the heptalenium dication and perhaps larger members of the series, such as the cyclohepta[b]heptalenium trication C₁₇H₁₃³⁺.