pka_value	data_source	charge_state_pre	charge_state_post	microspecies_pre	microspecies_post	molid	smiles
2.9	IUPAC digitized pKa	1	0	NC1=[NH+]NC(=O)C1	NC1=NNC(=O)C1	mol4004	NC1=NNC(=O)C1
