CC(=O)Nc1cccc(NC(=O)C(=O)NCC(c2ccco2)N2CCc3ccccc3C2)c1
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?