Consider the following two compounds: (I) [10]-annulene (II) 1,6-methano[10]annulene Which of the following statements correctly describes their aromatic character?

Step-by-step solution

Compound (I), [10]-annulene, possesses 10 electrons which satisfies the Hückel (4n+2) rule for n=2 . However, due to severe steric repulsion between the internal hydrogen atoms, the ring cannot maintain planarity. Consequently, it lacks a continuous cyclic electron delocalisation and is non-aromatic. Compound (II), 1,6-methano[10]annulene, has the internal hydrogens replaced by a - CH ₂- bridge. This structural modification ties the ring back and removes the trans-annular steric hindrance, allowing the 10 perimeter