O=C(O)c1ccc2c(=O)n3c(nc2c1)/C(=C/c1cccc(Cl)c1Cl)CCCC3
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?