Vibrational (FT-IR and FT-Raman) and NMR studies on selected metal (Ca, Mn, Zn) complexes with ortho-, meta-, and para-iodobenzoic acids

The vibrational (FT-IR and FT-Raman) and NMR (H-1 and C-13) spectra of Ca, Mn, and Zn complexes with ortho-, meta-, and para-iodobenzoic acids have be en studied. The solid state samples of all complexes have been measured wit hin the range 4000-400 cm(-1), while water solutions of ortho-iodobenzoates within the range 4000-800 cm(-1). Based on previous experimental data and normal mode calculations for simpler complexes the assignment of bands obse rved in vibrational spectra of studied compounds has been done. Some signif icant differences in vibrational structure (frequency and intensity of sele cted bands) have been observed and discussed. The effect of metal on ring v ibrations and carboxylic anion stretching and deformation has been investig ated. Also, influence of iodine substitution on the aromatic ring and carbo xylic anion, depending on iodine ring position, has been discussed. In case of soluble compounds, wavenumbers of characteristic bands of water solutio n samples have been compared with wavenumbers of corresponding bands of sol id state samples. (C) 1999 Elsevier Science B.V. All rights reserved.