Alkynes contain triple bonds between carbon atoms from "summary" of NCERT Chemistry Class 11 - [CBSE Board] by Dr. S. C. Rastogi, ,Er. Meera Goyal
Alkynes are a class of hydrocarbons that are characterized by having triple bonds between carbon atoms. These triple bonds consist of one sigma bond and two pi bonds. The presence of these multiple bonds gives alkynes some unique properties compared to alkanes and alkenes. The triple bond in alkynes is formed by the overlap of sp hybridized orbitals on the carbon atoms. This results in a linear shape for the alkynes, with a bond angle of 180 degrees. Due to the presence of the triple bond, alkynes are relatively more reactive than alkanes and alkenes. The presence of pi bonds in alkynes also leads to restricted rotation around the triple bond. This rigidity in the molecular structure affects the physical properties of alkynes. For example, alkynes have higher boiling points compared to alkanes and alkenes of similar molecular weight. This is because the triple bond in alkynes results in stronger intermolecular forces. Alkynes can also undergo addition reactions, similar to alkenes, due to the presence of the pi bonds. These addition reactions can lead to the formation of various organic compounds with functional groups. Furthermore, alkynes can be used in organic synthesis to construct complex molecules.- The presence of triple bonds between carbon atoms in alkynes gives them a unique set of properties and reactivity. Understanding these characteristics is crucial for studying organic chemistry and its applications in various fields.