Halogen Acid Reaction

Group 17 elements, known as halogens, are nonmetals. At room temperature, fluorine and chlorine are gases, bromine is a liquid, and iodine a solid. Astatine is a highly unstable radioactive element, so currently, most of its properties are unknown due to its short half-life. Tennessine is a synthetic element also predicted to be in this group. The halogens are not found as single atoms but exist as diatomic molecules. The atomic radius increases from fluorine to iodine. The valence shell...

Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide. The reaction of toluene with an excess of chlorine can produce multiple benzylic chlorinations. However, the reaction of N-bromosuccinimide or NBS with toluene in the presence of a peroxide forms benzyl bromide. Halogenation of larger alkyl side chains are highly regioselective and occur primarily at the benzylic position. Bromination of ethylbenzene...

An acid-base reaction is one in which a hydrogen ion, H+, is transferred from one chemical species to another. Such reactions are of central importance to numerous natural and technological processes, ranging from the chemical transformations within cells or lakes and oceans to the industrial-scale production of fertilizers, pharmaceuticals, and other substances essential to the society. There are several ways of defining an acid. In the context of aqueous solutions, an acid is a substance...

Arenediazonium substitution reactions occur when the diazonium group is substituted by various functional groups such as halides, hydroxyl, nitrile, etc. For instance, arenediazonium salts react with copper(I) salts of chloride, bromide, or cyanide to form corresponding aryl chlorides, bromides, and nitriles. These reactions are named Sandmeyer reactions. Although the mechanism of this reaction is complicated, as illustrated in Figure 1, they are believed to progress via an aryl copper...

A method involving the transformation of methyl ketones to carboxylic acids using excess base and halogen is called the haloform reaction. It begins with the deprotonation of α hydrogen to form an enolate ion which reacts with the electrophilic halogen to give an α-halo ketone. The step continues until all the α protons are substituted to form a trihalomethyl ketone. The resulting molecule is unstable, and in the presence of a hydroxide base, it readily undergoes nucleophilic acyl substitution.