Aromatic Chemistry Flashcards
Define Aromatic Compounds
Organic compounds with 1 or more Benzene ring
Define Benzene
Aromatic compound with 6 C atoms, 6 H atoms & ring of delocalised e-
Outline the bond lengths of:
C-C Bonds
C=C Bonds
C-C in Benzene
in nanometers
C-C = 0.154
C=C = 0.134
C-C (Benzene) = 0.139
Is Benzene saturated or unsaturated?
Saturated - all bond lengths same
How is the central ring of Benzene formed?
Outer e- from p-orbital delocalised
Ring makes Benzene stable
What’s another way of saying Aromatic Compounds?
Arenes
Outline the melting and boiling points of Arenes
MP = high due to delocalised ring stability
BP = low due to non-polarity
What bonding sequence do Benzene rings undergo? Why?
Electrophilic Substitution - e- ring has high e- density so electrophiles attack
What happens to the e- ring during electrophilic substitution?
Partially destroyed then restored
What products can form during the electrophilic substitution of benzene?
Nitrobenzene and Aromatic Amines
Outline the electrophile for the electrophilic substitution to form Nitrobenzene and how it’s formed.
NO2+ ion
Formed in the reaction H2SO4 + HNO3
Outline the reaction for the formation of the nitrobenzene electrophile
H2SO4 + HNO3 -> H2NO3+ + HSO4-
H2NO3+ -> H2O + NO2+
How does Nitrobenzene form?
NO2+ electrophile replaces a H+ ion
What’s the condition for a mono-substitution of Nitrobenzene to occur?
55 degrees Celsius - above causes multiple
How do you normally name Aromatic Compounds?
Prefix = whatever is bonded to the ring (e.g bromo-, nitro-)
Suffix = -benzene
(e.g: Bromobenzene)
What are exceptions to naming aromatic compounds?
C6H5OH = Phenol not Hydroxybenzene
C6H5NH2 = Phenylamine not Aminobenzene
What reaction type is turning Nitrobenzene into Phenylamine compounds?
Reduction
Outline the conditions for turning Nitrobenzene into Phenylamine compounds
NaOH (aq)
