Infra-red study of lipid-water systems.

The work described in this thesis has been divided into two parts. In part one the infra-red spectra of pinacol, a model compound with two OE groups, and its monohydrate and hexahydrate have been recorded at the beam temperature and low temperature and assignments made of the principle vibrations in each case. Also low temperature spectra of pure and partly deuterated substances have been recorded. These spectra are discussed in terms of their crystal structures which have been investigated previously by X-ray diffraction. Certain features of the hydrogen bonding in pinacol and its hydrates have been elucidated from a study of the decoupled OR stretching vibrations. In part two a number of lipids and lipid/water systems have been studied. The polymorphism of four 1-monoglycerides has been investigated. Transition temperatures have been determined and the thermal stability of the various polymorphs has been investigated. The structure of the various polymorphs has been investigated using infra-red spectroscopy. Assignments of the principle vibrations have been made of the most stable form of the pure and partly deuterated 1-monooctanoin. Infra-red spectra of 1-monooctanoin in solution have been obtained and conclusions have been drawn about the hydrogen bonding of l-monooctanoin in the dissolved state. The 1-monooctanoin/D[2]O phase diagram has been determined and the structure of the neat liquid crystalline phase of this system, along with that of the 1-monooctanoin/D[2]O system, have been investigated using polarized and unpolarized infra-red spectroscopy. Polarized and unpolarized infra-red spectra, and X-ray long spacings of dimethyldecyl- and dimethyldodecylphosphine oxide have been obtained. Assignments of the principle vibrations have been made and the results are discussed in terms of a model structure. The dimethyldecylphosphine oride/H[2]O phase diagram has been determined and the structures of the neat and middle liquid crystalline phases of this system and the dimethyldodecylphosphine oztide/H[2]O system, as well as the hydrated solid phase of the dimethyldecylphosphine oxide/H[2]O system have been investigated using polarized and unpolarized infra-red spectroscopy. Useful information has been obtained on the hydrogen bonding in most of these systems.