Daizy Philip

Infrared, Raman, and SERS Spectra of Betaine Arsenate

Abstract Infrared and Raman spectra of betaine arsenate are recorded and analyzed. It is found that protonation of betaine occurs at the expense of proton from H3AsO4. Further, H2AsO4 and H3AsO4 groups coexist in the crystal. SERS spectrum is recorded in silver colloid. Chemisorbed arsenate species is found to have a C3v symmetry. Betaine arsenate molecule has two adsorption sites.

Infrared and Raman spectra of aquamolybdenum (VI) oxide hydrate (MoO3·2H2O)

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 Oh symmetry became active in the Raman spectrum. Co-ordinated (aquated) and hydrated (interlayer) water molecules give rise to different frequencies.

IR and polarized Raman spectra of (NH3)2(CH2)2HPO4

Abstract The IR and polarized Raman spectra of (NH3)2(CH2)2HPO4 have been recorded and analyzed. In the crystal, symmetry of the HPO4 ion is found to be reduced from C3v to C1. The observed splittings indicate that the site symmetry and the correlation field effects are appreciable in the crystal. Strong vibrational coupling between the PO(H) stretching and POH out-of-plane bending modes is observed. Ethylene diammonium groups are crystallographically different in the unit cell.

Polarized raman and infrared reflection spectra of Cu(HCOO)2•2(NH2)2CO•2H2O

Abstract Polarized IR reflection and Raman spectra of Cu(HCOO) 2 · 2(NH 2 ) 2 CO · 2H 2 O single crystals have been recorded. The reflection spectra have been analyzed by means of a four-parameter dielectric function. Vibrational bands due to HCOO − , (NH 2 ) 2 CO, and H 2 O have been identified. The formate ions are found to be identical in the crystal. Fermi resonance between CH symmetric stretching mode of HCOO − and combination bands in the region between 2800 and 3000 cm −1 is observed. The presence of large urea molecules between copper formate layers is responsible for the lowering of the wavenumber of out-of-plane CH bending and reduction in intensity of the CO asymmetric stretching of HCOO − .