Cc1cccc(N2CCN(C(=O)CCn3c(=O)[nH]c4ccsc4c3=O)CC2C)c1
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?