Electrophilic Substitution to Nitrobenzene
I'm trying to draw the resonance contributors of nitrobenzene carbocation intermediate with the electrophile on the carbon with the hydrogen that it will substitute. I know nitro is meta director and I'm trying to convince myself diagrammatically how the charges distribute if the electrophile adds in each case of ortho/para- and meta-positions.
So far I can draw 5 contributors when electrophile and hydrogen are in ortho/para-positions but I feel I'm getting a little stuck with how the arrows should be drawn and which heteroatoms should be carrying what charge. I can see that there are adjacent positive charges that is a bad situation. When it comes to the meta-position where its most stable, I can draw the contributors in the ring so that the positive charges are not adjacent to each other. But I have trouble accounting and drawing the nitro group resonance.
Its uncomfortable to try to visualise from words what I'm trying to do. When I get to school, I'll scan my attempt if someone could provide critical feedback, but if anyone knows some pictures online or has a scanned diagram so that I can compare, I'd really appreciate it.