CCC1(C)Cc2c(sc3c2c2ncnn2c2nnc(SCC(=O)NCc4ccco4)n32)CO1
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?