Structures of the chain metaphosphates NaM(PO3)3 (M = Ca or Sr)

✍ Scribed by I. Abrahams; G. E. Hawkes; A. Ahmed; T. Di Cristina; D. Z. Demetriou; G. I. Ivanova

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 211 KB
• Volume: 46
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.2161

✦ Synopsis

Abstract

Solid‐state ^23^Na and ^31^P magic‐angle spinning nuclear magnetic resonance spectroscopy and X‐ray crystallography have been used to study the structures of the chain metaphosphates NaCa(PO~3~)~3~ and NaSr(PO~3~)~3~. The compounds are isostructural and crystallise in space group P~−1~ with the following parameters: NaCa(PO~3~)~3~, a = 6.711 Å, b = 6.934 Å, c = 7.619 Å, α = 83.44° , β = 81.41° , γ = 82.80° ; NaSr(PO~3~)~3~a = 6.805 Å, b = 7.133 Å, c = 7.720 Å and α = 83.71° , β = 80.48° , γ = 82.87° . Both structures contain anionic metaphosphate chains of (PO~3~)~n~^n^ with ionic contacts to Na^+^ ions in distorted octahedral sites and Ca^2+^ (or Sr^2+^) in distorted dodecahedral sites. ^31^P and ^23^Na NMR are entirely consistent with the crystallographic data and an empirical method for assigning ^31^P resonances to particular crystallographically unique P atoms is described. Copyright © 2008 John Wiley & Sons, Ltd.