CCOc1cc(C(C(=O)NCC2CCCO2)N(C(=O)Cn2nnc3ccccc32)c2ccc(OC)c(OC)c2)ccc1O
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?