Oc1ccc(C[C@H]2CN([C@@H](Cc3ccccc3)CN3CCC[C@@H]3CN3C(=S)NC[C@@H]3Cc3ccccc3)C(=S)N2CC2CCCCC2)cc1
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?