The spectroscopic (FT-IR, FT-Raman, UV and 1H, 13C NMR) and theoretical studies of alkali metal o-methoxybenzoates

The effect of alkali metal cations (Li→Na→K→Rb→Cs) on the electronic structure of o-methoxybenzoic acid was studied. The experimental IR, Raman, UV and 1H, 13C NMR spectra of o-methoxybenzoic acid and its salts were registered, assigned and studied. The structure of studied compounds were optimised in the B3LYP/6-311++G** level. The IR, 1H and 13C NMR spectra, and Mulliken atomic charges were calculated. The change of metal along with the series: Li→Na→K→Rb→Cs caused: 1) the change of electronic charge distribution in o-methoxybenzoate anion what is seen via the occurrence of the systematic shifts of several bands in the experimental and theoretical IR and Raman spectra of o-methoxybenzoates, 2) systematic chemical shifts for protons 1H and 13C nuclei, 3) hipsochromic shifts in UV spectra of salts as compared to ligand.