19F NMR study on pentacyclo[4.3.0.02,3.03,8.05,7]nonanyl and tetracyclo[3.3.1.02,8.04,6]nonanyl cation

By comparison of the 19F chemical shift of p-fluorophenyl substituted Coates cation 1 with that of triasteryl cation 2, πσ-participation by the remote cyclopropyl group in ion 1 is shown to be more effective than σ-participation by the adjacent cyclopropyl group in ion 2 in the delocalization of positive charge.