O=C1c2ccccc2C(=O)C12OC(c1ccccc1)C1(C(=O)c3ccccc3C1=O)C2c1cccc([N+](=O)[O-])c1
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?