Aromaticity and hydrogenation patterns in highly strained fullerenes

Gradient corrected density functional theory is applied to evaluate the structure and energetics of hydrogenation patterns in the C36 molecule and its component fragments. Overall strain and resonance energies for these compounds are determined using homodesmotic reactions that connect C36 and its constituent chemical components to simpler non-aromatic, unstrained compounds. Our calculations indicate that the dramatic difference in energetic stability between two similar solid C36 structures is due to the number of disrupted aromatic rings rather than to differential strain.