# Why is 1-bromotriptycene inert to nucleophilic substitution?

According to my textbook, 1-bromotriptycene is inert to any nucleophilic substitutions.

Due to steric hinderance we can say SN2 reactions cannot occur, but I think SN1 reactions should be favoured as formed carbocation will be resonance stabilised.

Can someone explain why it doesn’t undergo SN1 reactions?

• Hard to get resonance stabilization. You can't align the vacant orbital on the carbocation with the $\pi$ electrons on the ring. – Oscar Lanzi Dec 9 '17 at 10:55
• Think of the consequences of an SN1 or SN2 reaction. – user55119 Dec 9 '17 at 21:43