O=C(O)CCCCCNC(=O)CCC(CN(CC(=O)OCc1ccccc1)CC(=O)OCc1ccccc1)N(CC(=O)OCc1ccccc1)CC(=O)OCc1ccccc1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?