O=C(Nc1ccc(Cl)cc1Cl)C1C(=O)N(c2ccc(Cl)cc2Cl)C(=O)/C1=N\Nc1ccc([N+](=O)[O-])cc1[N+](=O)[O-]
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?