Alkyl radical

Alkyl radicals are molecular fragments formed by removing a hydrogen atom from an alkane, resulting in a species with an unpaired electron. They are important reactive intermediates in many chemical reactions, particularly in organic chemistry. They have a general formula of CnH2n+1 and are typically formed by homolytic bond cleavage induced by heat, light, ionizing radiation, electrical discharges, redox reactions, or electrolysis. The radical carbon has a trigonal planar geometry (sp² hybridization) with the unpaired electron in a perpendicular p orbital. Alkyl radicals are classified as primary (1°), secondary (2°), or tertiary (3°) based on the substitution of the radical carbon. Their stability increases in the order methyl < primary < secondary < tertiary, primarily due to hyperconjugation and differences in C-H bond dissociation energies. Common examples include methyl, ethyl, propyl, and butyl radicals. They are named by replacing the "-ane" suffix of the parent alkane with "-yl". Due to their high reactivity, most alkyl radicals have short lifetimes and act as transient intermediates.

Other names

Alkyl groupAlkyl free radicalAlkyl intermediate

Alkyl radicals are highly reactive intermediates with an unpaired electron, participating in chemical chain reactions by initiating (formation), propagating (reacting with other molecules to form new radicals), and terminating (combining to form stable products).