c1ccc(/N=C2\SC(=NNc3ccccc3)S\C2=N/c2ccccc2)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?