The structural features of three new [XC(O)NHP(O)(O)Y]ˉ[H2Y]+ amido-phosphate salts [X = CCl3 and Y = NHC6H4(2F) (1); X = CCl3 and Y = N(C2H5)(C6H11) (2); X = C6H5 and Y = (NHC6H4(3Cl) (3)] are studied. For each of structures (1) and (2), the asymmetric unit is composed of one cation-anion pair; while for (3), it consists of two symmetrically independent cation-anion pairs. In both structures (1) and (2), the anions and cations are linked via ―H2N—H…Oδ– hydrogen bonds into linear arrangements; parallel to the b axis for (1) and parallel to the a axis for (2). In structure (3), the cations and anions are hydrogen-bonded to each other forming a linear arrangement along the b axis; so that in this aggregation, the hydrogen-bonded dimers of anions, built from N—H…O═C hydrogen bonds, are connected to the neighbouring cations via ―HN—H… Oδ– hydrogen bonds. For the N―H…O hydrogen bonds, the donor...acceptor (N...O) distances of cation-anion compounds (1) – (3) and six analogous phosphate salts found in the Cambridge Structural Database (CSD) are compared with the values related to neutral C(O)NHP(O)-based structures.

Keywords