CCNC(=S)/N=c1\sc(NCC)nc2sc3c(c12)CCN(N1CCc2c(sc4nc(NCC)s/c(=N\C(=S)NCC)c24)C1)C3
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?