Methine group

The methine group (CH) is a functional group in the field of organic chemistry. It consists of a carbon atom to which a hydrogen atom is bonded, and thus has a hydrogen atom less than the methyl group. The free valences are saturated by three further substituents or by multiple bonds. Wherein the carbon atom of the methine group is a tertiary carbon atom. The substituents may be both organic and inorganic principle. The term methine the Methantriyl ( R3CH, 1) Methanyliden ( 2) methylidyne ( 3) and the Methenogruppe (4) are combined. The carbon atoms of aromatic compounds, if they carry no substituents can be regarded as methine groups, although no localized double bond exists.

Among the simplest compounds which formally contain a methine group include acetylene ( C2H2), propene (CH3 -CH = CH2) and isobutane (CH3 -CH ( CH3) - CH3). Furthermore, the group of polymethine dyes is known. The methylidyne group occurs at a nitrogen atom bonded in the ( methylidyne - λ5 - azanyl ) cyclopropane for example.