COc1ccccc1N1CCN(C(S)=Nc2ccc3nc(N4CCOCC4)cc(C)c3c2)CC1
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?