RAMAN SPECTRAL STUDIES OF SOLUTIONS AT ELEVATED-TEMPERATURES AND PRESSURES .13. SODIUM FORMATE WATER

Raman spectra of the formate anion in water (H2O and D2O) have been me asured for four concentrations under ambient conditions and for two co ncentrations at temperatures ranging from 49 to 239-degrees-C and a pr essure of 10 MPa. Five of the six fundamental modes of vibration are p olarized. This result is inconsistent with C2v symmetry. The Fermi res onance doublet clearly results from the interaction of 2nu5 and nu1. T he latter mode decreases in frequency as the temperature rises, thus i ncreasing the coupling and hence the intensity of the 2nu5 component. The coupling constant, W, and the positions of the unperturbed bands 2 nu5(0) and nu1(0) have been calculated. No evidence to support a bifur cated structure for the solvated anion was found.