CCCN1Cc2cccc(C(=O)Nc3ccc(-c4nc5ccccc5[nH]4)cc3)c2C1=O
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?