CCOP(=O)(OCC)C(Nc1ccc(C(=O)O)cc1)c1ccc(C(Nc2ccc(C(=O)O)cc2)P(=O)(OCC)OCC)cc1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?