Question

7.30 7.487.44 - 7-724 7.72 H Ha 8.32 57:46 7.49 8:36 8.0 Proton to which would be more at lughes ppm will be less lower ppm. is attached to anthracene. deshielded and this. while the Hy proton deshielded. Hence at

How is proton H_a more deshielded than proton H_b

Answer 1

Ha is is more desheilded by anthracene ring since it more aromatic (resonance energy 64 Kcal/mol) than benzene which has 36 Kcal/mol.