Radicals

What is a radical?

A molecular entity that has an unpaired electron. It is highly reactive due to the presence of an unpaired electron.

How is the movement of a single electron shown?

Single line arrow (fish hook)

How is the movement of a single electron shown?

Single line arrow (fish hook)

Why is ultraviolet light required to form a radical?

Radicals are formed by bond breaking. Bond breaking is endothermic and requires energy to take place

What is homolytic bind fission?

The process where a covalent bond between 2 atoms in a molecule breaks with each atom taking one electron from the bond (forming radicals)

What is heterolytic bond fission?

When a covalent bond between 2 atoms in a molecule breaks with one atom taking both bonding electrons.

What does heterolytic bond fission result in?

The formation of ions

In which type of organic reactions does homolytic bond fission take place in?

The free radical substitution reacts of alkanes

In which type of organic reaction does heterolytic bond fission occur in?

The nucleophilic substitution reaction of halogenoalkanes

Why are alkanes relatively unreactive?

The C-H bond is non polar bond

C-C and C-H bonds are relatively strong

How do free radical substitution reactions occur? (3 steps)

Initiation: occurs in presence of UV light (Cl2 to 2Cl free radicals)

Propagation: keep the chain reaction going

Termination: remove free radicals from the system (ends chain reaction)

What is the term called where the a bond is broken by UV light where each atom takes one electron?

Photochemical homolytic fission