Are alkyl groups and radicals the same? For example aldehydes R-CHO.

1 Answer
Mar 31, 2014

#Alkyl# groups and #radicals# are not the same.

In its modern meaning, a #radical# is an atom, molecule, or ion that has unpaired valence electrons.

In this sense, an #alkyl# group is not a #radical# because all its electrons occur in pairs.

A #radical# was once defined as a group of atoms that took part in chemical reactions as a single unit.

According to that older definition, #alkyl# groups were #radicals#. The functional groups like #aldehyde# groups made the molecule reactive. But the #alkyl# groups stayed together as a unit.