CCCCn1nnc(NC(=S)NC(=O)c2ccc(OCC)c([N+](=O)[O-])c2)n1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?