CN(C)CCCN=C(S)N(Cc1cccs1)Cc1cc2cc3c(cc2nc1O)OCCO3
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?