O=C(NC1CCCCC1)C(c1ccco1)N(Cc1cccnc1)C(=O)C1COc2ccccc2O1
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?