text: The addition of a substituent to a homoaromatic compound has a large influence over the stability of the compound. Depending on the relative locations of the substituent and the homoconjugate linkage, the substituent can either have a stabilizing or destabilizing effect. This interaction is best demonstrated by looking at a substituted tropenylium cation. If an inductively electron-donating group is attached to the cation at the 1st or 3rd carbon position, it has a stabilizing effect, improving the homoaromatic character of the compound. However, if this same substituent is attached at the 2nd or 4th carbon, the interaction between the substituent at the homoconjugate bridge has a destabilizing effect. Therefore, protonation of methyl or phenyl substituted cyclooctatetraenes will result in the 1 isomer of the homotropenylium cation.