Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. I. Spectra of protiated and partially deuterated magnesium potassium phosphate hexahydrate

The Fourier transform infrared and Raman spectra of magnesium potassium phosphate hexahydrate and a series of its deuterated analogues were recorded and analyzed. By comparing the spectra recorded at room temperature with those obtained at the boiling temperature of liquid nitrogen and by studying the spectra of the series of partially deuterated MgKPO4·H2O an assignment was proposed for the observed bands. The unusual behavior for bands originating from the n4 modes of PO4 32 ions in the Raman spectra of partially deuterated analogues of MgKPO4·6H2O was explained by coupling and mixing of the n4ðPO4Þ mode and D2O librations. q 2003 Elsevier B.V. All rights reserved