Metylradikalen

Metylradikalen, also known as the methyl radical (CH3•), is a reactive species containing a carbon atom with three single–bonded hydrogen atoms and an unpaired electron. Its electronic structure can be described as having a planar geometry with sp^2 hybridization at the carbon center, although the radical is typically considered to have a slightly pyramidal structure due to the lone electron. The name derives from the Dutch “methyl” meaning “methyl group” and “radikalen” meaning “radical,” reflecting its classification as a free‑radical species.

The methyl radical is one of the simplest organic free radicals and plays a pivotal role in combustion, atmospheric chemistry, and polymerization processes. It is generated in laboratory settings via photolysis of chloromethane or dichloromethane, by thermolysis of methyl iodide, or through electron impact ionization of methane. Its short lifetime in the gas phase (on the order of microseconds) is due to rapid reactions with other radicals, oxygen, and molecules such as methane, forming products like methanol, formaldehyde, or ethane.

In oxidation reactions, the methyl radical reacts with oxygen to produce the methylperoxy radical (CH3OO•), which subsequently decomposes to formaldehyde and hydroperoxide. In polymer chemistry, methyl radicals initiate the growth of poly(methyl methacrylate) and related polymers via chain‑growth mechanisms. Environmental studies have shown that methyl radicals are intermediates in the degradation of hydrocarbons in the troposphere and in the oxidation of methane by hydroxyl radicals. Because of its high reactivity, detection of the methyl radical requires rapid or low‑temperature spectroscopic techniques such as electron paramagnetic resonance or laser flash photolysis coupled with ultraviolet absorption.