Question

Give examples of composite radicals.

Answer 1

In chemistry, a radical is an atom, molecule, or ion that has an unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize. Most organic radicals have short lifetimes.

Complete step by step answer:
Radicals that are neither acidic nor basic are called composite radicals.
Composite radicals usually are found under methane, methyl, and acetyl. Benzene, phenyl, or cyclohexane (for example, acetylamino, cyclohexane carbonyl).
Properties of free radical:
Free radicals are unique and rare species and are present only under special and limited conditions. However, some free radicals are familiar to us in our lives.
Molecular oxygen is a typical free radical, a biradical species. Standard and stable molecular oxygen is in a triplet state and the two unpaired electrons have the same spin orientation in two orbitals respectively, having the same orbital energy based on Hund’s rule.
Nitrogen monoxide and nitrogen dioxide are also stable, free radical species. Moreover, the reactive species involved in immunity are oxygen free radicals, such as superoxide anion radical and singlet molecular oxygen.
So free radicals are very familiar to us in our lives and are very important chemicals.
Free radicals are highly reactive and very unstable. They can donate an electron or accept an electron from other molecules, therefore, can behave as oxidants or reactants.

Note: The free radicals attack important macromolecules which leads to cell damage and homeostatic disruption such as proteins, nucleic acids, etc. Generally, alkyl halides or aryl halides are used as radical precursors for R or Ar however halogenation of sugars and nucleosides which have many OH groups and other delicate functional groups is rather difficult.