C[N+](C)(C)CC(=O)N/N=C/c1oc(-c2cccc([N+](=O)[O-])c2)c(-c2cccc([N+](=O)[O-])c2)c1[N+](=O)[O-].[Cl-]
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?