Open-Shell 3d Transition Metal Nitridophosphates M P N (M =Fe, Co, Ni) by High-Pressure Metathesis.

3d transition metal nitridophosphates M P N (M =Fe, Co, Ni) were prepared by high-pressure metathesis indicating that this route might give a systematic access to a structurally rich family of M-P-N compounds. Their structures, which are stable in air up to at least 1273 K, were determined through powder X-ray diffraction and consist of highly condensed tetra-layers of PN tetrahedra and MN octahedra. Magnetic measurements revealed paramagnetic behavior of CoP N and NiP N down to low temperatures while, FeP N exhibits an antiferromagnetic transition at T =3.5(1) K. Curie-Weiss fits of the paramagnetic regime indicate that the transition metal cations are in a oxidation state +II, which was corroborated by Mössbauer spectroscopy for FeP N . The ligand field exerted by the nitride ions in CoP N and NiP N was determined from UV/Vis/NIR data and is comparable to that of aqua-ligands and oxophosphates.