Pentadecaphyrin, a 4n-π-aromatic (n=18) trefoil with:
Lk =9, comprised T ~2 + W ~7.
B3LYP/6-31G(d): Δ
r
(meso) = 0.006Â
See DOI:
10.1021/ja710438j
for explanation of Lk, T and W.