Phosphorus oxonitridosodalites:: Synthesis using a molecular precursor and structural investigation by X-ray and neutron powder diffraction and 31P MAS NMR Spectroscopy

The oxonitridophosphates M8-mHm[P12N18O6]Cl-2 (M = Cu, Li) with a sodalite-like [P12N18O6](6-) framework of corner-sharing PN3O tetrahedra have been synthesized by the reaction of the respective metal chlorides with (NH2)(2)P(O)NP(NH2)(3) . NH4Cl. In this precursor the desired molar ratio, P:O = 2:1, of the [P12N18O6](6-) framework structure has been preorganized on a molecular level. Analogous oxonitridosodalites have also been obtained from the metal salts MX (M = Cu, Li; X = Cl, Br, I) or Li2S, the P/O and P/N components OP(NH2)(3) and SP(NH2)(3) or HPN2, and NH4X or MX as halogen sources. The crystal structures of the phosphorus oxonitridosodalites Cu4.8H3.2[P12N18O6]Cl-2 (1). Li5.5H2.5[P12- N18O6]Cl-2 (2); Li6.2H1.8[P12N18O6]Br-2 (3), and Li5.8H2.2[P12N18O6]I-2 (4) have been investigated by using neutron and X-ray powder diffraction as well as P-31 MAS NMR spectroscopy. Rietveld refinements have been performed in the space group <I(4)over bar>3m (Z = 1, a = 820.25(1) to 830.81(2) pm for X = Cl to I). No experimental evidence for a crystallographic ordering of the N/O atoms and for other than PN,O tetrahedra in the sodalite frameworks has been obtained.