Question

5. Circle the compounds below that are aromatic. Aromatic compounds obey Huckel's rule: they have 4n+2 Tt-electrons (where n = any integer including zero) in a closed, contiguous Tt-system (see pg 760, 764-766). Remember delocalized lone pairs are part of the T-system whereas localized lone pairs are not (see pg 765-768). Empty p-orbitals can also be part of the it-system.

5. Circle the compounds below that are aromatic.

Answer 1

According to Huckel monocyclic plana consungated polyene systems (cation, anion on not neufpal speenes) containing (yn+2) de localised Il-electrons exhibits aromatic property na al... to ne So conditions for compound to be anomatic. to molecule must have planars sing system. to Eash alom involved in the formation of ning system must have an by Sridised p-orbital and prospitals. must in Panallel amel unclerge continuous overlap to delocalisation of p electrons may contain leo, 2 eo on o but does not follow fun+2) . . total T electrons = 8 so not aromatic planar NA 7 not so = 8 follow lunt) and not amomatic

4 i elutron 6 Plana un+2) T eleet non follows. mal. B have vacant orbital cam aceppt passticipate in conjugation - a eo so N o anomantic To elutron 6. . (untz) a eo followed lone pain of n is not in conjugation. with sing so not consideped ! so aromatic a No conjugation so no' delocalised T o also not following (untz) a e o ron. a eo 6. follows (un+2) 7. planas corgingati so aromatic (untz) at e. follows but no conjugation ... so no delocalisation of t ee not possible. so not anomatic (un+2) .T eo follows with rial conjugation as B is having vacanf imbital. so aromatic

7 o a . s Planant: (unta) 7.1 with n=1. delocalisation of T io possible. aromatic not follows .~ so (Unte) t o not aromatic 0