Cc1cc(NC(=O)c2ccc(NC(=O)CCS(=O)(=O)c3cccs3)cc2)ccc1Br
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?