Oc1nc2cc3c(cc2cc1CN(Cc1cccnc1)Cc1nnnn1Cc1ccco1)OCCO3
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?