karbónýlhóp

The karbónýlhóp, also known as the carbonyl group, is a functional group in organic chemistry. It consists of a carbon atom double-bonded to an oxygen atom. The general formula for a molecule containing a carbonyl group is R–C(=O)–R', where R and R' can be hydrogen atoms or organic substituents. This functional group is central to many important classes of organic compounds.

When the carbonyl group is bonded to two alkyl or aryl groups, it is classified as a ketone. If one of the groups attached to the carbonyl carbon is a hydrogen atom and the other is an alkyl or aryl group, the compound is an aldehyde. If the carbonyl group is bonded to at least one hydroxyl group (-OH), it is a carboxylic acid. Esters are formed when the hydroxyl group of a carboxylic acid is replaced by an alkoxy group (-OR). Amides contain a carbonyl group bonded to a nitrogen atom.

The electronegativity difference between carbon and oxygen creates a polar bond within the carbonyl group, with the oxygen atom carrying a partial negative charge and the carbon atom carrying a partial positive charge. This polarity influences the reactivity of the carbonyl group, making the carbon atom susceptible to nucleophilic attack. This characteristic is fundamental to many organic reactions, including nucleophilic addition and condensation reactions. The presence of a carbonyl group is also responsible for the characteristic smells of many aldehydes and ketones.