O=C(CCn1c(=O)c2ccccc2n(Cc2cccc([N+](=O)[O-])c2)c1=O)N1CCc2ccccc2C1
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?