COc1ccccc1N=C(S)N(CCCN1CCOCC1)Cc1cn(C)c2ccccc12
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?