W28 - Aromatic Compounds

Flashcards reviewing key concepts related to aromatic molecules, aromaticity, reactions, and other related compounds.

What chemical formula does benzene have?

C₆H₆

What type of reaction does benzene resist?

Electrophilic addition

What causes aromaticity?

Delocalisation of π electrons

What is the resonance stabilization energy of benzene?

152 kJ mol-1

What is Hückel's rule?

Aromaticity occurs in planar ring compounds with (4n+2) π electrons.

What are the products of electrophilic substitution?

A new molecule and H+

What is the definition of resonance?

The representation of a structure of a molecule by two or more conventional formulae.

What are mesomeric effects particularly important for?

Understanding benzene chemistry

What acts as a Lewis acid catalyst in the bromination of benzene?

FeBr3

In nitration of benze, what acts as the Lewis base?

HNO3

In sulfonation of benzene, what acts as the Lewis base?

SO3

What are the two categories of substituted benzenes?

Activating substituent and Deactivating substituent

What does +M > -I mean?

There is a negative inductive effect (-I destabilises the ring) but the positive resonance effect (+M) is greater and drives the activation

What effects do the NO2 group exert?

A strong (-I) and (-M) effect

What are quinones found in?

Many basic red-ox processes in cells

What are FAD/FMN involved in?

Electron transfers and oxidation/reduction in biology

What does NAD utilize to stabilise oxidized and reduced forms?

Aromaticity

What does a planar aromatic nature of bases enable?

Alignment for H-bonding