Download Alkyne Nomenclature

Honors Chemistry II
ALKYNES
Alkynes - _______________ bonded hydrocarbons

Draw the simplest alkyne in kekule, condensed and shorthand.

What is its IUPAC name?

What is its common name?
Predict the type of hybridization that occurs in alkynes. Assign which bonds are sigma
bonds and pi bonds.
C
C
(ground state C)

(hybrid state C)
___ hybridization occurs (combination of _____ s and _____ p orbital)
+
+
+
+
+
+
sp
p
s
p
p
p
p
hybridized orbitals
sigma
pi
sigma
pi

What would be the geometry and bond angle?
Cycloalkynes

Why can’t 3 – 7 carbon rings contain triple bonds?

The smallest ring that is stable enough to be studied at room temperature is shown
below. Can you name it?
The C – C ≡ C – C bond angles are still strained
C
C
(~160˚), but are stable enough to study.
_______________
_______________ can be stored indefinitely due to
its increased stability, achieving 180˚ bond angles.
Discuss Sources and Uses of Alkynes Handout
Alkyne Nomenclature
The IUPAC rules for alkyne nomenclature are similar to alkane and alkene
nomenclature except that the suffix –yne is added to the end of the name to indicate the
triple bond. There is no rotation around the sigma bond because the two pi bonds fix the
atoms in place. There are no E or Z conformations because there is only one single bond
on either side of the triple bond.
Name these:
Draw these:
2-bromo-5,6-dimethylhept-3-yne
(3Z)-4-chloro-3-isopropylhex-3-en-1-yne
Cl