Vibrational analysis of Ag 3(PO 2NH) 3, Na 3(PO 2NH) 3.H 2O, Na 3(PO 2NH) 3.4H 2O, [C(NH 2) 3] 3(PO 2NH) 3.H 2O and (NH 4) 4(PO 2NH) 4.4H 2O

Abstract

FT IR and FT Raman spectra of Ag 3(PO 2NH), (Compound I), Na 3(PO 2NH) 3.H 2O (Compound II), Na 3(PO 2NH) 3.4H 2O (Compound III), [C(NH 2) 3] 3(PO 2NH) 3.H 2O (Compound IV) and (NH 4) 4(PO 2NH) 4.4H 2O (Compound V) are recorded and analyzed on the basis of the anions, cations and water molecules present in each of them. The PO 2NH − anion ring in compound I is distorted due to the influence of Ag + cation. Wide variation in the hydrogen bond lengths in compound III is indicated by the splitting of the v 2 and v 3 modes of vibration of water molecules. The NH 4 ion in compound V occupies lower site symmetry and exhibits hindered rotation in the lattice. The correlations between the symmetric and asymmetric stretching vibrations of PNP bridge and the PNP bond angle have also been discussed.