CN=C(S)Nc1ccc(C2(c3ccc(NC(S)=NC)c(C)c3)CCCCC2)cc1C
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?