A detailed photophysicochemical study of some non-transition metal (AI, Zn, Si, Ge, and Sn) metallophthalocyanine (MPc) derivatives is presented. The effects of substituents, central metal ions and solvents on the photophysical and photochemical properties are investigated and rationalized accordingly. The presence of peripheral substituents on the macrocycle enhances the yield of the triplet state. Near infra-red absorptions of the solvents reveal that solvents which absorb around 1100 nm and around 1270 nm, quench the triplet state of the MPc derivative and singlet oxygen, respectively. Although water has a high singlet oxygen quenching effect, the singlet oxygen quantum yield (Φ∆) value for sulphonated zinc phthalocyanine in water is still reasonably high at 0.48, which may provide an explanation for the efficient photosensitization by this molecule in photodynamic studies. The lowering of Φ∆ following protonation of the MPc macrocycle is attributed to the lowering of triplet energy to the level where energy transfer to ground state oxygen is no longer favourable. MPc inclusion complexes with cyclodextrins showed larger Φ∆ values when compared to the complexes before inclusion. Job's plots show that 2:1 and 4:1 (CD:MPc) complexes may be formed. Fluorescence quenching by electron donors and acceptors were analysed by StemVolmer relationship and the results used in determining fluorescence lifetimes of the complexes. Qualitative and quantitative interpretations of the interaction of sulphonated MPcs with bovine serum albumin (BSA) are provided in this thesis. 1:1 adducts were formed with BSA, but the binding feasibilities varied markedly. Spectral, photophysical and photochemical properties of the complexes are altered in the presence of BSA.

Flavanone (2,3-dihydro-2-phenyl-4H-benzopyran-4-one) and a series of 4'- and 7-halogeno derivatives were prepared from the corresponding 2'-hydroxychalcones [1-(2-hydroxyphenyl)-3-phenyl-2-propen-l-ones], which, in turn, were synthesized by aldol condensation of substituted 2'-hydroxacetophenones with various benzaldehydes. A series of 2,3-dihydro-2-phenyl-l,4-benzoxazepin-5(4H)-ones were prepared by ring expansion of the corresponding flavanones, via the Schmidt reaction, using trimethylsilylazide and trifluoroacetic acid. A series of tetrazoles {2,3-dihydro-2-phenyl-tetrazolo[1,5-d]-1,4-benzoxazepines} were also isolated as by-products of the Schmidt reaction. Flavanone oxime was synthesized for use in Beckmann reactions, and its molecular structure was determined by x-ray crystallography. Attempts to prepare 1,4-benzoxazepinone or its 1,5-analogue via Beckmann rearrangement of flavanone oxime, with polyphosphoric acid or phosphorus pentachloride catalysts, however, were unsuccessful. Several methods for introducing Δ²-unsaturation into the benzoxazepinone system were also examined. High resolution ¹H n.m.r., computer modelling, and molecular mechanics techniques were used to determine the conformations of the heterocycles of the benzoxazepinones and tetrazoles and results are compared with earlier studies in this field. Certain trends in the fragmentation patterns were observed in the low resolution mass spectra of the benzoxazepinones and tetrazoles, and high resolution mass spectrometric data were used to explore the major fragmentation patterns of these compounds.

This study is concerned with the association characteristics of solutions of alcohols in some non-polar solvents. The permittivities at 2 MHz and 25°C for solutions of the straight chain octanols in cyclohexane, carbon tetrachloride and benzene have been examined over the entire solute concentration range, with particular attention -1 being paid to the range below 0.1 molℓ⁻¹ By applying the Kirkwood- Fröhlich equation to these data, the apparent dipole moments of the alcohols as a function of concentration have been evaluated. These concentration dependencies have been correlated with infrared absorption results on the same systems to provide information on the sizes and configurations of the proposed hydrogen bonded multimers. It is concluded that, at very low solute concentrations, the alcohol molecules exist as monomers; but with increasing concentration, two types of hydrogen bonded multimers are formed, the first (at low concentrations) being of high dipole moment and the second (at higher concentrations) being of low dipole moment. At high concentrations, the molecules associate to form a three-dimensional network. Attempts have been made to determine equilibrium parameters for molecular models which are consistent with the qualitative understanding of the association behaviour. These parameters were obtained by applying least-squares, curve-fitting techniques to the low concentration permittivity data. A similar investigation has been conducted on solutions of 2,3,4-trimethyl-3-pentanol in the same solvents. The steric hindrance around the hydroxyl group of this alcohol modifies the association behaviour so that a three-dimensional network does not form at high solute concentrations. Proton magnetic resonance chemical shifts for the hydroxyl proton of this alcohol in carbon tetrachloride solutions have been measured. Attempts have also been made to determine equilibrium parameters which describe formation of the hydrogen bonded multimers. To extend this study to include solutes other than octanols, similar experiments have been conducted on solutions of t-butanol in hexadecane, a system which has recently been investigated by other workers using different experimental techniques. The association behaviour of this system is qualitatively similar to that of the straight-chain octanols. The combination of permittivity and infrared measurements, although proving extremely powerful in interpreting the association characteristics of dilute alcohol solutions, is less adequate at high solute concentrations. Attention was therefore directed towards dielectric relaxation and viscosity studies to investigate concentrated solutions. The relaxation times at 20°C of the low frequency dispersion have been measured for solutions of 1-propanol, 1-butanol, 1-hexanol, 1-octanol and 1-decanol in cyclohexane using time domain reflectometry techniques. Similar measurements have also been made on solutions of 1-butanol and 1-octanol in carbon tetrachloride and in benzene. The concentration dependence of the viscosities of certain of these systems has also been examined in an independent study. The ratio of the dielectric relaxation time to the viscosity, the "reduced relaxation time", is qualitatively similar for each system studied. This similarity leads to an explanation of the molecular process responsible for the low frequency dispersion in terms of the proximity of the hydroxyl groups in concentrated alcohol solutions and the fraction of the groups which are not involved in hydrogen bonding.

In this thesis mass spectral and chromatographic techniques were developed and applied to identify and characterise numerous novel platinum(II) and (IV) compounds designed as anticancer agents. In a novel method for the synthesis of cis-oxalato(trans- -1,2- cyclohexanediamine)platinum(II) or oxaliplatin these techniques could be applied to differentiate between the molecular complex and the autoionised analogue (viz. Ptdach2 2+Ptox2 2-). In another novel synthetic method for the same compound the ligand exchange reactions at various temperatures could be investigated and kinetic curves obtained served to illuminate the chemistry involved, indicating the role of small amounts of water in the essentially non-aqueous solvent systems dmf and isoamyl alcohol respectively. These allowed ligand exchange without resulting in hydrolyses even up to 85°C. The ionisation rate of divalent platinum halide complexes was determined for various amine ligands as well as N-S chelate ligands. A comparison of these could suggest why N-S complexes have poor anticancer action. Ionisation was not only studied for neutral molecular species but also for monocationic ones. Relationships could be found with stereochemical aspects of the chelates used. By investigating results of EV-CAD studies thermodynamic data could be obtained which indicated that bond strength decreases from chloro to iodo analogues although extent of ionisation in aqueous solution, i.e kinetic stability, is the reverse. Products formed by the reaction of NO2 gas with Platinum(II) compounds could be identified and separated which greatly contributed to the understanding of the chemistry involved in the formation of mononitro platinum(IV) complexes. Some of these proved to have exceptional anticancer properties. Studies of the interaction of thiol containing biomolecules were performed as a function of time. The results contributed to the understanding of the action of the anticancer agents.

The spark spectra of zinc have been photographed in the region between 990 Å and 2590 Å using a condensed spark in helium as source. Exposures were taken using a Hilger large quartz prism spectrograph and a 3 meter normal incidence vacuum grating spectrograph of local design. Of 1000 lines measured, some 228 were classified in the spectra Zn I, Zn II, and Zn III on the basis of square arrays constructed using energy levels from Moore's "Atomic Energy levels," volume II (1952). Also, 67 lines were classified in the third spark spectrum of zinc, Zn IV, enabling assignment of relative energies to 8 even levels belonging to the configuration 3d⁸ 4s and to 27 odd levels belonging to the configuration 3d⁸ 4p, In addition, use was made of 25 lines measured by Bloch and Bloch (1936) in the region below 500 Å in determination of the ground state 3d⁹²D. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

A sensitive, wide or narrow band, solid state spectrometer operating at a wavelength of 0.85 cm has been built which is described in detail. The spectrometer is of the crystal detector reflection-cavity-in-magic-Tee-bridge type and can operate from room down to liquid helium temperatures. The cavity Is excited In the TE₁₁₁ mode and the magnetic field modulated at 140 cps. Both large and small field modulations are incorporated for scope presentation of line width varying from about 0.5 to 500 gauss. Signals from single crystals of copper sulphate pentahydrate and polycrystalline 1-1-diphenyl-2-picryl hydrazyl (DPPH) have been obtained. From the latter, a sensitivity limit of about 10⁻⁸ gram is obtained at room temperature for a bandwidth of 1 cps indicating a sensitivity of the order of 10⁻¹¹ gram at 4.2° K. Various methods of improvement were discussed in order to reach the ultimate sensitivity. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Due to the many crystallographic and spectroscopic anomalies found in investigations of amides, polyamides, and imides, succinimide suggested itself as an interesting compound for spectral investigations. The spectrum of solid succinimide ( KBr pellet ) was recorded in the range 4000 - 250 cm⁻¹, whereas the spectra of vapour, single crystal, and solutions of succinimide in a variety of solvents and at varying concentrations, were obtained in the region 4000 - 250 cm⁻¹. For the recording of vapour spectra, and for the growth of thin sections of single crystals, special apparatus and techniques were devised and are described in detail. N - d - succinimide, N - h - succinimide - d₄, N - d succinimide - d₄, and various related compounds were also investigated. The absorption bands of succinimide have been assigned by comparison with spectra of related compounds and by studying association phenomena and isotope substitution effects. An PG matrix treatment has been undertaken and agreement between calculated and observed frequencies is good when only a minimum number of interaction constants are employed. The anomalous behaviour of succinimide in the Amide II and Amide III regions has been explained by the assumption of a dimer, as has the 3080 cm⁻¹ band. Solution studies indicate that the dimer exist even in moderately concentrated solution. / Science, Faculty of / Chemistry, Department of / Graduate

The spectra of zinc have been photographed in the region between 2400Å and 7000Å. Electrodeless discharge and Schuler tube were used as sources, and exposures were taken on a Hilger E-498 medium quartz spectrograph, a Hilger E-1 Littrow prism spectrograph and a 21 foot concave diffraction grating. There were 1200 lines measured in this region of which 110 were already classified. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

The spectra of Indium have been photographed from the infra-red to the vacuum ultra-violet on a two metre vacuum spectrograph, a twenty-one foot grating, and a Littrow prism spectrograph. Two sources have been used: an electrodeless discharge and a condensed vacuum spark. Some 1250 Indium lines have been measured in the region 8200 to 237 Angstroms. Oh the basis of these measurements, new energy levels have been found for all spark spectra up to In V. The main extension of analysis has been in In III where we have added thirty-five new terms. The resulting analyses have been critically examined in terms of intermediate coupling theory, which is shown to be satisfactory when perturbations are not present, except in one configuration in In IV in which there are serious departures from theory. Hyperfine structure has been measured in In III and In II, and perturbation calculations have been made which account for observed departures from the Landé interval rule. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

In order to facilitate a later determination (which, incidentally, will involve the study of hyperfine structure) of various nuclear properties of Cadmium, a preliminary survey, both experimental and theoretical, has been undertaken of the gross spectral structure of that element. A light source, consisting of an electrodeless discharge in which the excitation of the various spectra could be varied in some degree, was constructed and conditioned. The illumination from this source was then photographed with the aid of a Hilger EI Quartz Spectrograph; exposures were taken of the regions 6800Å - 3300Å, 3300Å - 2500Å, and 2500Å - 2000Å. The positions of the spectral lines appearing on the plates were measured with the aid of a Hilger comparator, and the wavelengths were then calculated by means of the Standard Hartmann dispersion formula. About 150 Cadmium lines which had already been listed by previous workers were identified; 21 other lines - apparently new ones, since to the writer's knowledge they have not as yet been mentioned in the literature - also were found. These latter lines were concentrated in the region 6000Å - 3900Å. Theory reveals that the hyperfine structure of Cadmium II should be of greater value in the above-mentioned determination than that of the arc spectrum. Therefore a study of an isoelectronic sequence Involving Cadmium II was carried out with an eye to increasing the knowledge of this first spark spectrum's term structure. The validity of the various optical doublet laws has been tested for such an exemplary isoelectronic sequence. / Science, Faculty of / Physics and Astronomy, Department of / Graduate