Except for formaldehyde, the simplest aldehyde, all aldehydes have a carbonyl group, C=O, bonded on one side to a carbon, and on the other side to a hydrogen. In ketones, the carbonyl group is situated between two carbon atoms
Oxidation-reduction and organometallic compounds (氧化-还原和有机金属化合物) 11.1 Introduction Carbonyl (羰基)compounds are a broad group of compounds that includes aldehydes, ketones, carboxylic acids, and esters
12.1 Introduction Systems that have a p orbital on an atom adjacent to a double bond---molecules with delocalized pibonds– are called conjugated unsaturated systems