[O-][Cl+3]([O-])([O-])[O-].c1ccc(-c2cc(-c3ccccc3)[n+](-c3ccccc3)c(-c3ccccc3)c2)cc1
Molecules with a polar surface area of greater than 60 angstroms squared (Å2) is hard to pass brain blood barrier. What's the psa of this molecule?