N#Cc1c(N2CCOCC2)[nH]c(=O)c(C(c2c(Cl)cccc2Cl)c2c(O)c(C#N)c(N3CCOCC3)[nH]c2=O)c1O
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?