O=C(Cn1c(=O)n(Cc2ccc3c(c2)OCO3)c(=O)c2oc3ccccc3c21)Nc1ccccc1F
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?