CC(C)OP(=O)(OC(C)C)/C(=N/Nc1ccc([N+](=O)[O-])cc1)NCCN/C(=N\Nc1ccc([N+](=O)[O-])cc1)P(=O)(OC(C)C)OC(C)C
A lower number of pka indicates that the acid dissociates more entirely in water. What is pka of the molecule?