I read that vinyl or aryl carbocations do not have resonance stabilization but I can't understand why that is the case. Below I have drawn some resonance structures for aryl and vinyl carbocations: Aryl carbocation: https://imgur.com/QwiHJg8 Vinyl carbocation: https://imgur.com/rKBs57d In both images, the bottom resonance structures results in the carbocation to change in its hybridization (sp to sp2) which seems like its the reason why the delocalization is not possible. However, in benzonitrile the nitrogen at the edge changes from an sp hybridization to an sp2 hybridization as well in the resonance structures it forms (https://qph.is.quoracdn.net/main-qimg-9c9c4891e3c59fe96adbc8caf19efc6a?convert_to_webp=true [Broken]). So why is it okay for benzonitrile to change its hybridization in this manner while this cannot happen for the vinyl/aryl carbocation? For the top images, why can't the electrons delocalize in that manner? Would it be because for that to happen, the electrons would have to delocalize into the other p orbital that is empty which is not parallel to the other p orbitals?