Coordination hydrogen bonds in the structures of different tris(pyridin-2-yl)phosphoric triamide derivatives.

The crystalline forms of tris(pyridin-2-yl)phosphoric triamide, OP[NH-Py] were investigated using single crystal X-ray diffraction, both as a metal complex [Co{(O)P[NH-Py][NH-PyH]}]Cl, compound 1, and as the purely organic pseudopolymorphs, the pure/anhydrate OP[NH-Py], 2, monohydrate 2OP[NH-Py]·HO, 3 and solvate 2OP[NH-Py]·2DMF·HO, 4, respectively. An improved model of the metal organic framework (MOF) structure of Cu(ii)O {[Cu(OCHO)][(CH)NH]} , 5 is also reported. Compound 1 is the first example of a discrete chelate phosphoric triamide (PT) complex with an [N]P(O)-based backbone which in the PT compound acts as a flexible tridentate ligand.