O=C(O)CSc1c2c(nc3cc(C(=O)N4CCCCCC4)ccc13)CCCC2
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?