Spectroscopic studies of alcohol and water systems.

The work described in this thesis is concerned with a study into hydrogen bond formation in alcohol and water systems using NMR and Infrared spectroscopy. For the latter, the fundamental, first and second overtone regions are all investigated and use is made of computer graphics in order to decompose the second overtone spectra. The NMR work probes the changes in the hydrogen bond environments of alcohol, amine and water systems in various binary mixtures and on the addition of aprotic bases. For ethanol and water, ternary mixtures are also investigated. The results are discussed in terms of the reacting lone pairs and O-H or N-H groups - these labelled as (OH)free, (NH)free (LP)free species. The fundamental infrared work incorporates a study of ethanol and water in inert solvents in the O-H stretch region and of ethanol in the C-O-H bend region. Further work in the bend region is carried out on bulk solutions of ethanol, water and base binary mixtures. The results for the ethanol systems show a good agreement with work done in other regions (NMR, infrared stretch region) in that the addition of base weakens the ethanol environment. However, the water systems prove to be anomalous and reasons for this are given. The first and second overtone regions (near infrared) are investigated for water/alcohol and water/base systems, the latter region proving to be more informative. The loss of water (OH) free groups is determined from the spectra with the use of computer graphics and this shows that the originally labelled" (OH)free " peak is, in fact, only 40% free, the remainder being weakly hydrogen bonded species. These results are then compared with a theoretical approach using the Law of Mass Action. A good correlation is found between experimental and theory and this leads to an accurate classification of the basicity of the bases studied.