O=C(NCc1ccccc1)[C@@H]1C[C@H]1[C@@H](NP(=O)(c1ccccc1)c1ccccc1)c1ccccc1
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?