[O-][Cl+3]([O-])([O-])[O-].c1ccc(-c2[o+]c(-c3ccccc3)c(-c3ccccc3)c(-c3ccccc3)c2-c2ccccc2)cc1
Molecules with a polar surface area of greater than 140 angstroms squared (Å2) tend to be poor at permeating cell membranes. What's the psa of this molecule?