N#CCCn1cc(/C=C2\NC(=S)N(c3ccccc3)C2=O)c(-c2ccc(-c3ccccc3)cc2)n1
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?