LOW FREQUENCY MOLECULAR MOTIONS IN WATER AND ICE AND THE EFFECTS OF IONS AND ORGANIC SOLVENTS ON THE STRUCTURE OF WATER.
FELTMAN RESEARCH LABS PICATINNY ARSENAL DOVER N J
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The inelastic scattering of low energy .005 eV neutrons was used to investigate the structure of water and the effects of various ions and organic solvents on the structure of water. The gross features of the neutron spectra of ice and water are known. However, with improved resolution, additional peaks were observed in ice 250K at 50, 62, 76, 103, and 150cm. Similar peaks are observed in water at 293K but become less pronounced at higher temperatures. The intense peak attributed to hindered rotations centered at 585cm in ice 250K can be decomposed into peaks at 550, 650, and 800cm, assuming Gaussian shapes with the width determined by instrumental resolution and the intensity by level population. No similar decomposition can be made for the broader torsional peak in water. The neutron spectra of 2M and 5M KSCN, and 2M CaC12 solutions display an increased broadening in the torsional region of the spectra and a decrease in structure below 100cm. This is attributed to a reorganization of the clusters around the ions in the liquid and changes in overall cluster size and inter-atomic distances. The neutron spectra of deuterated organic solvents 3.7M acetone, 3.9M dimethyl sulfoxide in water were also obtained. Author
- Radiation and Nuclear Chemistry
- Atomic and Molecular Physics and Spectroscopy