Nc1nnc(SCC(=O)Nc2sc3c(c2C(=O)c2ccccc2)CCCC3)s1
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?