1
$\begingroup$

1H-pyrrol-1-ium

It has 4n electrons and is completely conjugated. It should be anti aromatic.

Why is this compound non-aromatic?

$\endgroup$
  • 4
    $\begingroup$ Pyrrole is aromatic because it has six electrons in its conjugated $\pi$ system. This thing has four. $\endgroup$ – Ivan Neretin Jan 26 '17 at 6:45
  • $\begingroup$ @IvanNeretin This thing has 4 electrons, so it must be anti aromatic. Why it is non aromatic? $\endgroup$ – Arishta Jan 26 '17 at 9:13
  • 4
    $\begingroup$ Why should it be antiaromatic? It does not even have a cyclic conjugated $\pi$ system anymore. $\endgroup$ – Ivan Neretin Jan 26 '17 at 9:17
  • $\begingroup$ Not fully conjugated. There is a saturated atom in the cycle. $\endgroup$ – Oscar Lanzi May 7 '17 at 22:24
2
$\begingroup$

It is non-aromatic even though it has 4$\pi$ electrons because nitrogen cannot form five bonds. Hence delocalisation is not possible and so it is non aromatic.

$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.