Six new crystal structures, [4-Cl-C6H4C(O)NH]P(O)[NR1R2]2 (NR1R2 = N(CH2C6H5)2 (1), NHCH2C6H5 (2), NHC6H4(4-CH3) (3)) and [RC(O)NH]P(O)[N(CH3)(CH2C6H5)]2 (R = 3-F-C6H4 (4), (3,5-F2)C6H3 (5)) and [(3,5-F2)C6H3C(O)NH]P(O)[NH]2C5H10 ...