COc1ccc(N2CCN(CCNC(=O)c3ccc4c(c3)nc(S)n3c5ccccc5nc43)CC2)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?