Electrophilic attack
Electrophiles are species that love negative electrons. They are normally electron deficient or have a slight positive charge. The pi-bond of an alkene can be thought of as a large, juicy, pair of electrons that can go out and attack these electrophiles. When the pi-bond grabs hold of an electrophile, it leaves a positive charge behind on the other carbon atom. Alkynes contain carbon-carbon triple bonds. They contain one sigma bond and two pi-bonds. They are sp hybridized. The more bonds that exist between two carbon atoms, the shorter the distance is between the two carbon atoms. Another way to think about it is the greater the “s-character” of the hybridization, the closer an atom will hold its electrons to its nucleus because s-orbitals have the electron density closer to the nucleus than p-orbitals.
A Generic Electrophilic Attack
