The infrared and Raman spectra of MoO₃·2H₂O are recorded and analysed on the basis of vibrations due to MoO₆ octahedra and H₂O molecules. Considerable changes in the frequencies of the octahedra have been observed due to strong distortion in the octahedral arrangement. The inactivev₆ vibration of O_h symmetry became active in the Raman spectrum. Co-ordinated (aquated) and hydrated (interlayer) water molecules give rise to different frequencies.

The infrared and Raman spectra of crystalline samples of NdP₅O₁₄, NaNdP₄O₁₂ and KNdP₄O₁₂ are recorded. The spectra are analysed on the basis of vibrations of P=O, P-O, PO₂ and P-O-P groups. The P₄O₁₂⁴⁻ ion has cyclic structures both in NaNdP₄O₁₂ and KNdP₄O₁₂ crystals. It has been inferred that the P-O-P bridges are stronger in metaphosphates.

The IR and Raman spectra are measured and analysed for sodium pyrophosphate decahydrate. The spectra are interpreted on the basis of P₂O₇⁴⁻ ion and water vibrations. The observed results fit with the features predicted for the factor goup model. The appearance of two sets of frequencies in the stretching and bending regions of water suggests the existence of two kinds of water molecules in the crystal. This is confirmed by deuterium substitution.

IR and Raman spectra of (NH₄)₃ZnCl₅ have been recorded. The observed spectra have been analysed on the basis of the vibrations of ZnCl₄²⁻ and NH₄⁺ ions. The appearance of multiple Raman bands indicates the presence of two different types of ammonium ions. The effect of anisotropic crystalline field over the ZnCl₄ and NH₄ tetrahedra is also discussed. The assignment of internal modes has been verified by the potential energy distribution calculations.

SERS studies of 1-butylaminoanthraquinone in silver sol have been made to understand the nature of adsorption. The enhancement mechanism is explained on the basis of charge transfer process. The molecule is adsorbed through the binding sites but not flat on to the surface.

Raman scattering studies on 1–4 dihydroxyanthraquinone (DHAQ) at Ag electrode have been carried out to investigate the enhancement in the spectral line intensity after adsorption. Charge transfer between the adsorbate and the substrate is more pronounced for certain normal modes of vibration. It is found that the DHAQ molecules are lying with their molecular plane on the top of the metal surface. Laser induced fluorescence spectra of DHAQ have also been analysed with a view to assign the relative orientation of absorption and emission dipoles.

Intense Raman scattering by acetophenone molecules adsorbed on colloidal silver particles is reported. Greater enhancement is observed for the ring breathing and ring stretching vibrations. The orientation determination analysis shows that the adsorption of acetophenone molecule is neither through its co-ordinating site nor through itsπ-orbital system and there is no strong chemical interaction. However significant intensity enhancement for several vibrations suggests that the contribution is from classical electromagnetic field on the rough surface.