[pesona3f]

for arylamine and alkyl amine, is there any relationship between basicity and resonance stability?

i read a book and it said that arylamine in term of resonance is relatively stable to alkylamine because of five resonance structure and that cause it has low basicity..

i really dont understand the relationship...

[lancenti]

Ar-NH₂ suffers a lower basicity because the lone pair on the nitrogen atom is delocalized into the aromatic ring. This results in a diminished availability for donation as per the definition of a Lewis Base. (If it can't donate the electron pair, it can't act as a base.)

R-NH₂ suffers a higher basicity because the lone pair on the nitrogen atom is 'pushed out' by the electron density of the alkyl group as it is electron donating. (If the lone pair is more readily available for donation, it'll be more basic)

[pesona3f]

yes, that absolutely true... but i wonder if stability and basicity have some relation.. and as i mention, the book says that because ArNH2 have resonance structure, and it make it stable and thus low basicity....