Nitrophilic Aromatic Experiments

In Period 11 of lab, two experiments were conducted: one investigative and one preparative. Both experiments demonstrated the theory and concepts behind electrophilic aromatic substitution. As the term states, the experiments deal with the chemistry of six membered ring compounds and their transformations through electrophilic substitutions.
This type of reaction transforms the aromatic compound by allowing various functional groups to be attached to it. The general process of this reaction is a hydrogen on an aromatic ring, most simply an arene, being replaced by an electrophile. The substitution sometimes requires the electrophile to be produced through reaction and a base might be required to remove the hydrogen from the aromatic ring. So overall the reaction takes place in three steps. The first step is the production of the electrophile that will be used in the substitution by reacting an electrophile containing compound and a catalyst. The second step is the reaction of the electrophile and an aromatic compound, which results in a cation intermediate. This step is a second order step, also called the rate-determining step. The final step is cation intermediate …show more content…
In this reaction, the nitro group is added to the ring through a mixture of sulfuric and nitric acid. The mixture of the two acids forms an nitronium ion, which is the group that is added to the arene. The nitration reaction is relatively similar to the general reaction mechanism for this type of substitution, except that the nitration of bromobenzene results in three distinct bromo-nitrobenzene products: ortho, para, and meta. The ortho and para forms of the product are more stable than the meta form. The two stable forms need to be separated from each other, which is done through fractional crystallization and leaves the para form in solid form since it is less soluble in polar