1
Chapter 16 Worksheet Key
1. For each compound below, state the number of π-electrons in the conjugated
cycle, if any, and state whether the compound is aromatic, antiaromatic, or nonaromatic.
2. non-conj.
Pi-system
nonaromatic
1.cyclic,
planar
2.conj. pisystem
3. 4e-
1. cyclic, planar
2. conj. pisystem
3. 10e-
1. cyclic, planar
2. conj. pisystem
3. 6e-
aromatic
aromatic
antiaromatic
1. cyclic, planar
2. conj. pi-system (as
part of the conj. pisystem)
3. 18earomatic
(lone pairs on N
in plane)
2. no conj. pisystem
nonaromatic
1. cyclic,
planar
2. conj. pisystem in the
benzene part
3. 6e
2. no conj. pisystem
1. cyclic, planar 1. cyclic
2. no conj. pi2. conj. pi-system
system
3. 6e
nonaromatic
nonaromatic
aromatic
aromatic
© John Congleton
2
2. no conj. pisystem
1. cyclic
2. conj. pi-system
3. 10e- in plane
1. cyclic
2. 2 sets of conj. pisystems
Aromatic (sides…)
3. 2 sets of 6e-
non aromatic
aromatic
aromatic
1. cyclic, planar
2. conj. pisystem
3. 4e-
1. cyclic but
not planar…
2. conj. pisystem
3. 10e-
antiaromatic
2. no conj.
pi-system
2. no conj.
pi-system
nonaromatic
nonaromatic
1. cyclic, planar
2. conj. pi2.No-conj.
sysytem
System
3. 6e-
1. cyclic but probably
not planar
aromatic
nonaromatic
nonaromatic
nonaromatic
© John Congleton
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3. For each compound below, state the number of π-electrons in the conjugated
cycle, if any, and state whether the compound is aromatic, antiaromatic, or nonaromatic. Show how the π-electrons are delocalized by drawing all the significant
resonance structures for each compound.
a.
-
6earomatic
HN
N
-
+
+
+
HN
HN
--
N
these can't move...
HN
N
N
+
back to orig.
HN
N
-
b.
B
H
H
H
4eantiaromatic
_
_
B
H
_
B
B
+
+
+
H
_
B
+
c.
N
10earomatic
N
N
© John Congleton
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d.
+
+
+
+
-
2e
aromatic in this f orm...
e.
O
O+
6earomatic
-B
B
O+
-B
4. Draw the following compounds.
(a) m-vinylbenzoic acid
O
OH
(b) p-bromophenol
OH
Br
(c) o-(3,5-dinitrophenyl)toluene
© John Congleton
5
NO2
toluene
5
6
CH3
4
1
3
2
NO2
(d) 3,4-dichloro-N,N-diethylaniline
N
Cl
Cl
© John Congleton