O=C1NC[C@H](Cc2ccccc2)N(C[C@@H]2CCCN2C[C@H](Cc2ccccc2)N2C[C@H](Cc3ccccc3)N(CC3CCCCC3)C(=O)C2=O)C1=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 negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?