{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

l7 - Cyclic Systems Aromatic Antiaromatic 4n 2...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Cyclic π Systems Aromatic 4n + 2 electrons ( Hückel’s Rule ) Antiaromatic any other electron count Non Cyclic π Systems Non Aromatic 6 electrons 4 electrons 6 electrons aromatic antiaromatic nonaromatic Aromatic systems Cyclopentadiene is not stable for long at room temperature. It reacts with itself to form a dimer. 2 Diels Alder heat NaOH pKa = 16 FeCl n e = 6 2 Fe(C 5 H 5 ) 2 ferrocene page 1011 in book Aromatic systems Cycloheptatrienyl cation n e = 6 n e = 6 Dibenzenechromium Cr(C H )(C H ) 7 7 5 5 Cr(C 6 H 6 ) 2 Cycloheptatrienyl cation n e = 6 Stable cation also known as the tropylium ion BF 4 - Antiaromatic system cylcooctatetraene non planar n e = 8 Aromatic system C H 2- n = 10 C 8 H 8 e 10 Heterocycles (cyclic molecules with at least one non carbon atom) N N All N N pyrimidine pyridine benzene N pyrazine n e = 6 sp 2 N N lone pair N H on Nitrogen pyridinium
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Heterocycles (cyclic molecules with at least one non carbon atom) H H All N pyrrole N N imidazole n e = 6 sp 2 hybridized 2 electrons N N N N in sp 2 hybrid
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}