general formula of this series is CnH 2 n−2. In naming these compounds, the alkane
suffix is replaced by -yne. Two examples:
The orbital structure of ethyne can be shown as follows:TIP
Notice that pi bonds are between p orbitals and that sigma bonds are between s and p orbitals.The bonds formed by the p orbitals and the one bond between the sp orbitals
make up the triple bond.
The preceding examples show only one triple bond. If there is more than one
triple bond, modify the suffix to indicate the number of triple bonds. For example,
2 would be a diyne, 3 would be a triyne, and so on. Next add the names of the
alkyl groups if they are attached. Number the carbon atoms in the chain so that the
first carbon atom in the triple bond nearest the end of the chain has the lowest
number. If numbering from both ends gives the same positions for two triple
bonds, then number from the end nearest the first alkyl group. Then, place the
position numbers of the triple bonds immediately before the name of the parent
hydrocarbon alkyne and place the alkyl group position numbers immediately
before the name of the corresponding alkyl group.
Two more examples of alkynes are: