NC(=O)c1ncn(CCN2CCN(C(=O)NCCCCCCNC(=O)N3CCN(CCn4cnc(C(N)=O)c4N)CC3)CC2)c1N
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?