Methyl group

Different types of representation for the methyl group marked in blue . R = hetero atom, organyl radical, such as alkyl , alkenyl , aryl etc. or other radicals with a free valence.

The methyl group (also known as the methyl radical ) is one of the simplest atomic arrangements in organic chemistry . The formula is –CH ₃ . It is not an independent chemical substance, but always part of a larger molecule. It is the simplest alkyl group and can be found in many chemical compounds. Their systematic names then contain the syllable "-methyl-" (e.g. 2-methylbutane ).

In the technical literature, the methyl group is sometimes abbreviated as “Me”, so CH ₃ OH for methanol (methyl alcohol) becomes MeOH.

properties

As usual for alkanes , methyl groups are extremely inert. They only react under drastic conditions, for example in the oxidation of p - xylene (1,4-dimethylbenzene) with potassium permanganate to terephthalic acid (1,4-benzenedicarboxylic acid). In these cases, the reactivity of the methyl group is also increased by the neighboring aromatic ring.

A methyl group has a positive inductive effect , e.g. B. on a neighboring benzene ring, since the carbon atom has an electron-pushing effect on the ring. The methyl group therefore directs the second substituent in the electrophilic substitution in the ortho and para positions.

See also

• Methine group (CH)
• Methylene group (CH ₂ )
• Ethyl group (C ₂ H ₅ , often short: Et)
• Propyl group (C ₃ H ₇ )
• Phenyl group (C ₆ H ₅ , often short: Ph)
• Methylation

Individual evidence

1. ^ Brockhaus ABC chemistry. VEB FA Brockhaus Verlag, Leipzig 1965, p. 875.