Infrared and Raman spectra of three tetrametaphosphates M PO( M = Fe, Ni, Zn).

The infrared and Raman spectra of three tetrametaphosphates M PO ( M = Fe, Ni, Zn) have been recorded and analysed. A factor group model has been used to interpret the spectra of FePO and NiPO. A free ion model could explain the ZnPO spectra. The frequencies have been assigned on the basis of characteristic vibrations of PO and P-O-P groups. The PO ion is found to have C symmetry in FePO and NiPO and C in ZnPO. The ion in FePO is more distorted than in the other two. [ABSTRACT FROM AUTHOR]