CNc1ncnc2c1ncn2[C@H]1C[C@H](OP(=O)(O)O)[C@H](COP(=O)(O)O)O1.N.N.N.N
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?