Electron-withdrawing groups are groups whose electron cloud density on benzene ring decreases when substituents replace hydrogen on benzene ring. On the contrary, the electron cloud density on benzene ring increases, which is called electron donor group. Whether a group is an electron-withdrawing group or an electron-donating group depends on the sum of its induced effect on benzene ring, * * yoke effect and super * * yoke effect.

In the chemistry of carbonyl clusters, carbonyl ligands have many different bonding modes. The most common carbonyl ligands are terminal ligands, but carbonyl groups often connect two or three metal atoms to form μ2 or μ3 bridged ligands. Sometimes carbon atoms and oxygen atoms in carbonyl groups will participate in bonding. For example, μ3-η is a bridging ligand with a Harpto number of 2, which connects three metal atoms.

Definition of carbonyl group

Carbonyl is an organic functional group (C=O) composed of carbon and oxygen atoms connected by double bonds, and it is a component of functional groups such as aldehydes, ketones, carboxylic acids and carboxylic acid derivatives. In organic reactions, carbonyl groups can undergo nucleophilic addition reaction, reduction reaction and so on. The carbonyl group of aldehyde or ketone can also undergo oxidation reaction. In addition, in coordination chemistry, carbon monoxide ligands are also called carbonyl groups.

Carbonyl usually refers to a group formed by combining a carbon atom hybridized with sp2 or sp with an oxygen atom through a double bond. In organic chemistry, carbonyl compounds refer to a class of compounds containing carbonyl groups.

Refer to the above content: Baidu Encyclopedia-carbonyl