This study reports the synthesis of two rare-earth imidonitridophosphates and a series of 3d transition metal imidonitridophosphates (MIIIH3P6N12 with M = V, Cr, Eu, Lu, and MIIH4P6N12 with M = Mn, Fe, Co, Ni) by high-pressure metathesis. The crystal structures were elucidated by a combination of single-crystal and powder X-ray diffraction, elemental analysis, and vibrational spectroscopy. All compounds crystallize in the orthorhombic crystal system (transition metal imidonitridophosphates: Cmce, EuH3P6N12: Pna21, LuH3P6N12: Pbam) and feature a layered anionic network composed of vertex-sharing PN4 tetrahedra. Magnetic measurements indicated that Mn, Fe, Co, and Ni are in the oxidation state + II, while V, Cr, Eu, and Lu are in the oxidation state + III. Furthermore, the measurements revealed paramagnetic behavior for all compounds except LuH3P6N12 and indications of antiferromagnetic ordering at low temperatures for NiH4P6N12 and CrH3P6N12. The oxidation states of Fe and Eu were further confirmed by Mössbauer spectroscopic measurements. As LuH3P6N12 does not exhibit paramagnetic behavior, additional NMR spectroscopic measurements were conducted. Furthermore, luminescence measurements provided information that supported the structural characterization and gave insights into the ligand field strength of the coordination sphere of the metal atoms in the considered imidonitridophosphates, indicating that the PN4 units show weakened coordination behavior.
Zipkat et al. (Fri,) studied this question.