Cn1c(C(=O)N2CCC(C(=O)NCCc3ccc(S(N)(=O)=O)cc3)CC2)cc2sccc21
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?