O=C(Nc1ccccc1)N(CCN(Cc1ccccc1)C(=O)Nc1ccccc1)CCN(Nc1ccccc1)C(=O)Nc1ccccc1
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?