p-systems can easily be formed by a new preparative method. Similar to the S_NAr-reaction sterically shielded triarylmethyl-cations react with different C-and N-nucleophiles to dipolar para-quinonedimethanes. The use of coordinating endgroups allows the synthesis of twice-substituted products, which show solvatochromism and halochromism. Intramolecular neighbouring group effects are introduced by 1,8-donor- acceptor-substituited naphthalene derivatives. Especially the Me₂N-substituent interacts with a peri-located triarylmethyl-cation under cyclization. The reaction of (8-Chloro-1-naphtyl)-bis(4-methoxy-phenyl)-methyl- tetrafluoroborate with malonitrile leads to 1-Dicyano-2-bis-(4-methoxyphenyl)- acenaphthene as another model compound for stretched ring systems