RAMAN AND FT-IR STUDIES OF PB-4(NO3)(2)(PO4)(2)CENTER-DOT-2H(2)O CRYSTAL

Lead nitrate phosphate single crystals were grown in silica hydrogel a t room temperature. A controlled reaction was employed between orthoph osphoric acid and lead nitrate solution by the slow diffusion process in the gel medium. The laser Raman and FT-IR spectra of the lead nitra te phosphate crystal were recorded. The vibrational assignments of PO4 3-, NO3- and H2O vibrations have been approximated in terms of T-d, D- 3h and C-2v symmetry species, respectively. The vibrational modes of P O43- ion indicate that this ion is distorted in this crystal and its s ymmetry is lowered to free ion symmetry. The vibrational spectrum indi cates that the NO3- ion is slightly distorted in the crystal. From the spectrum the presence of water molecules is indicated.