Chem 415 2014
Topicity
April 9 2014
Problem Set 2 Key
1) Assign a point group for each of the molecules below.
2) Identify the topic relations of like ligands that are described below the structural formulas
(homotopic, enantiotopic, diastereotopic, or constitutionally heterotopic)
Ph
H
H
Br
Me
Ph
Point Group: Cs
Me/Me (at 300 K)
diastereotopic
Point Group: C1
H/H diastereotopic
Ph/Ph const. heterotopic
Point Group: C2
HA/HB const. heterotopic
CH2OH/CH2OH homotopic
Ph
H
Me
H
Me
N
tBu
H
Me
H
Me
Ph
Point Group: D4h
HA/HB enantiotopic
HA/HC homotopic
Point Group: C1
Me/Me diastereotopic
H/H diastereotopic
Point Group: C2
H/H homotopic
Me/Me homotopic
Point Group: C2
Cl/Cl homotopic
H/H diastereotopic
Point Group: C3v
Cl/Cl/Cl homotopic
Point Group: Ci
Me/Me enantiotopic
Point Group: Ci
H/H diastereotopic
H/H enantiotopic
Point Group: C3
H/H/H homotopic
Point Group: Cs
H/H diastereotopic
Me/Me enantiotopic
H
Me
C
Me
H
1
Chem 415 2014
Point group Cs
H/H enantiotopic
Me/Me diastereotopic
Topicity
April 9 2014
Point group C4v
H/H diastereotopic
OH/OH homotopic
Point group Cs
H/H enantiotopic
Me/Me const. heterotopic
Point group Cs
H/H diastereotopic
Me/Me enantiotopic
Point group C2
H/H diastereotopic
Me/Me homotopic
Point group D5h
Ha/Hb enantiotopic
Ha/Hc homotopic
Point group Cs
H/H const. heterotopic
Me/Me enantiotopic
Point group C2
Point group C1
H/H homotopic
H/H diastereotopic
Me/Me const. heterotopic Me/Me const. heterotopic
Point group Ch
Me/Me homotopic
H/H homotopic
Point group Ci
Me/Me enantiotopic
Cl/Cl enantiotopic
2
Point group C3
Ha/Hb diastereotopic
Hc/Hd homotopic
Chem 415 2014
Topicity
April 9 2014
Identify the topic relations of like ligands that are described below the structural formulas
(homotopic, enantiotopic, diastereotopic, or constitutionally heterotopic)
A
B
Ha/Hb enantiotopic
Ha/Hb enantiotopic
Hc/Hd homotopic
Hc/Hd enantiotopic
C
D
H/H diastereotopic
Ha/Hb diastereotopic
Me/Me homotopic
Hc/Hd homotopic
E
F
H/H diastereotopic
Ha/Hb homotopic
OH/OH homotopic
Hb/Hc homotopic
Assign point groups to the molecular formulas A–F from part b).
A
B
C
D
E
F
C2v
C2v
C2v
C2
C7
D2d
3