JEE MAIN - Chemistry (2005 - No. 47)
Tertiary alkyl halides are practically inert to substitution by SN2 mechanism because of
insolubility
instability
inductive effect
steric hindrance
Forklaring
Due to steric hindrance tertiary alkyl halide do not react by $${S_N}2$$ mechanism they react by $${S_N}1$$ mechanism. $${S_N}2$$ mechanism is followed in case of primary and secondary alkyl halides .
The order is
$$C{H_2} - X > C{H_3} - C{H_2}X > {\left( {C{H_3}} \right)_2}CH.X > {\left( {C{H_3}} \right)_3}C - X$$
The order is
$$C{H_2} - X > C{H_3} - C{H_2}X > {\left( {C{H_3}} \right)_2}CH.X > {\left( {C{H_3}} \right)_3}C - X$$