start by looking atalkenes, or organic compounds that have at least one double bond between carbon atoms. The double bonds in alkenes arecovalentbonds, meaning that electrons are shared between the atoms

Double bonds can have sigma and pi bonds. Sigma bonds are pretty strong, whereaspibonds are a little weaker. The electrons in the pi bond move around a little more and are more likely to be attacked byelectrophiles, or things that are attracted to the negative portion of a compound.

Think of electrophiles as the home wreckers of the organic chemistry world. The suffix 'phile' means 'to like' or 'attracted to', and electrons are negative, so you can see how electrophiles get their name. And these electrophiles like to break up those double bonds by attacking the pi bonds. Electrophiles typically have a positive charge. So maybe electrophiles aren't really home wreckers. I mean, they're not breaking up a marriage, but they are breaking up double bonds, so maybe there's some similarity? No? Okay, okay. Let's take a closer look at some reactions.

Addition Reaction

In anaddition reaction, two compounds come together to form one larger compound. Here, we will discuss the addition reactions of alkenes. Let's take a look at a few examples so you can see what an addition reaction looks like.

Let's look at the reaction of hydrogen bromine (HBr) and propene (C_3H_6).

Here, HBr will become the electrophile. Bromine hogs the electrons in the HBr bond, thus making the hydrogen slightly positive and the bromine slightly negative. See image A.