Benzene is an important organic compound with the chemical formula C6H6, and its molecule consists of a ring of 6 carbon atoms, each with 1 hydrogen atom. Benzene is a sweet, flammable, colorless and transparent liquid with carcinogenic toxicity at room temperature, and has a strong aromatic odor. It is insoluble in water, easily soluble in organic solvents, and can also be used as an organic solvent itself. The ring system of benzene is called benzene ring, and the structure after removing one hydrogen atom from the benzene ring is called phenyl. Benzene is one of the most important basic organic chemical raw materials. Many important chemical intermediates can be derived from benzene through substitution reaction, addition reaction and benzene ring cleavage reaction.
In organic chemistry, a carbonyl group is a functional group with the formula C=O, composed of a carbon atom double-bonded to an oxygen atom, and it is divalent at the C atom. It is common to several classes of organic compounds (such as aldehydes, ketones and carboxylic acids), as part of many larger functional groups. A compound containing a carbonyl group is often referred to as a carbonyl compound.