Pyrrole template

Pyrrole: the neutral form and four charge-separated forms with N⁺ and the negative charge on C3, C5, C2 and C4.

What the template shows

• The nitrogen lone pair is part of the aromatic sextet
• Resonance contributors
• Negative charge on each ring carbon in turn (β, α, α, β)
• The N lone pair is one of the six π electrons, so pyrrole is aromatic but hardly basic (pKaH about −3.8; it protonates on carbon).
• The ring carbons are electron-rich: pyrrole reacts with electrophiles much faster than benzene, mainly at C2.
• The charge-separated forms are minor (charges, N⁺ next to C⁻) but show where the ring is electron-rich.
• Contributors are not in equilibrium: the real species is one hybrid of them · every part of this figure is editable

Drawn with 25 atoms, 12 arrows, 2 shapes – every one editable in MolDraw.

Sources

• Clayden, Greeves & Warren, Organic Chemistry, 2nd ed., OUP 2012 Textbook
• Smith, March's Advanced Organic Chemistry, 8th ed., Wiley 2020 Textbook