Aromatic interactions in a non-porous solvents have been significantly overlooked in the past few decades. In contrast aromatic interactions in polar solvents, in particular water have been studied extensively leading to an in depth understanding of these interactions and driving forces in these media. The first chapter of this thesis reviews the nature of aromatic interactions, how to best define and evaluate their strength, as well as presenting a historical perspective on aromatic interactions in non-polar environments. The second chapter of this thesis describes the strength and driving forces of aromatic interactions in such solvents as heptane, methylcyclohexane, dibutyl ether, squalene and chloroform. This was evaluated by studying an archetypal aromatic donor-acceptor complex between that of naphthalenediimide and dialkoxynaphthalene. A combination of 1H NMR, UV-vis spectroscopy and isothermal calorimetry techniques were employed to elucidate their strength and thermodynamic functions. In the third and fourth chapters the knowledge acquired concerning aromatic interactions in non-polar environments was then employed in the design of lubricant additives. In Chapter 3, as potential friction modifiers in which their behaviour on metal surfaces was probed using reflective absorbance infrared spectroscopy, sum frequency generation spectroscopy, as well as initial rig tests. Finally in chapter 4, as potential soot solubilisation agents in which the interaction of various polycyclic aromatics with perylenediimide was monitored by UV-vis spectroscopy.

A series of new 4-methoxybenzylaminoacetonitriles has been prepared and characterised. These have been cyclised with concentrated sulphuric acid and a new non-classical mechanism is postulated. Depending on the nature and position of the substituent groups on the nitrile the following classes of compound have been prepared: 4-oxo-tetrahydroisoquinolines, 3-imidazolines, 3,3-disubstituted tetrahydroisoquinolines, N-substituted tetrahydroisoquinolines, 2-benzazepines. The mechanism postulated satisfactorily explains the formation of all the above classes of compound and also the formation of certain 3,3-disubstituted-4-oxo-tetrahydroisoquinolines previously reported. Structural assignments have been made by means of elemental analysis and infrared spectroscopy; extensive use has been made of nuclear magnetic resonance and mass spectroscopy. Several new compounds have been tested for biological activity.

The work reported in this thesis is concerned with the study, by a gravimetric method, of the reaction of carbon dioxide with a high-purity carbon derived from the polymer cellulose triacetate. Particular attention has been paid to the influence on reaction kinetics of hydrogen, both residual in the carbon and as a gaseous impurity. The factors which affect the rate of reaction of carbons with oxidising gases are discussed and an account of the accepted theory of kinetics and mechanisms of the carbon-carbon dioxide reaction is given, together with some features of the reaction not accounted for by this theory. Heat treatment of cellulose triacetate carbons in the range 1273K-1773K was found to produce a maximum in the rate of reaction with carbon dioxide. The observed maximum has been accounted for in terms of two competing processes, elimination of hydrogen resulting in enhanced reactivity and the annealing of active sites resulting in a decrease in reactivity. A number of additional experiments have been performed in an attempt to separate the effects of different factors on the kinetics; these include a study of the effects of isothermal annealing of carbons and chemical pre-treatments with hydrogen and chlorine. A compensation effect, i.e. a linear relationship between all measured values of activation energy E and log A, the pre-exponential factor in the Arrhenius equation has been observed. A review of the literature relevant to the compensation effect is given and some examples of its application, particularly to gas-carbon reactions, are discussed. A theoretical treatment relating particularly to the carbon-carbon dioxide reaction has been developed and used as a basis for interpretation of the experimental results.

The study of some condensation reactions of malonyl chloride with nitriles revealed some very interesting results. It was found that fluoroacetonitrile reacted with malonyl chloride in the molar ratio of 2:1 and yielded 4-chloro-2-fluoromethy1-6-hydroxypyrimidine (65%). The reaction of malonyl chloride with chloroacetonitrile produced mainly 2-chloromethyl-4-chloro-6-hydroxy-pyrimidine along with some 2,3-dichloro-4,6-dihydroxy-pyridine. In contrast, like fluoroacetonitrile acetonitrile, bromoacetonitrile and a-bromopropio nitrile with malonyl chloride yielded exclusively their corresponding pyrimidines. The structures of these pyrimidines and pyridines were established with the aid of nuclear magnetic resonance, mass spectrometry, infrared and ultraviolet light absorption spectroscopy. Their structures were also confirmed by chemical transformations. The formation of RCOC1 along with the pyrimidines has been established by nuclear magnetic resonance,isolation of a characteristic derivative, and gas-liquid chromatography. The possible mechanisms of this new synthesis of pyrimidines have been discussed. In seeking evidence, some syntheses were performed with malonyl chloride labelled with carbon-14. The results of these experiments with labelled malonyl chloride and with halogenomalonyl chlorides showed that all the three carbon atoms of malonyl chloride appeared in the pyrimidine nucleus whilst all of the carbon atoms of the RCOC1 product belonged originally to the starting nitrile. An interesting feature of this new synthesis of pyrimidines is that it is the first direct synthesis of chloro-pyrimidines in which halogen appears at an active position of the ring.

In Part I, previous chemical work on vanguerolic acid and tomentosolic acid, triterpene acids of Vangueria tomentosa, is discussed. Unequivocal confirmation is then presented for the structure of tomentosolic acid as 19,20-dehydroursolic acid. This has been obtained by correlating tomentosolic acid with ursolic acid by hydrogenation of a derivative of the former. A 18,19-dehydroursolic acid structure for vanguerolic acid is proposed, and evidence is presented for a p configuration of the methyl group at position 20. The reactions of vanguerolic acid are rationalised, and a plausible biogenetic scheme for vanguerolic and tomentosolic acids is suggested. Part II comyences with a review of the chemistry of diterpenoid bitter principles in general, and of clerodin from Clerodendron infortunatum in particular. The previously postulated relative position between the spiro epoxide and the 1,3 diol system in clerodin has been fully confirmed by a detailed investigation of "blerodin diketone". The partial structure for the dihydrofuran moiety of clerodin has been extended. In particular, the "inert" oxygen atom has been chemically shown to be joined to the same carbon as that to which the oxygen of the dihydrofuran system was attached. Chemical and nuclear magnetic resonance spectral evidence, combined with biogenetic considerations have led to a structure (LIII) for clerodin, which is the same as that determined independently by X-ray methods. The absolute configuration of clerodin, and the chemistry of some interesting degradative products are discussed. A minor plant constituent has been isolated, and its relationship to clerodin elucidated.

The various types of sesquiterpenoids are discussed in terms of their structural and biogenetic relationships. Possible biosynthetic pathways are proposed for all types, and some existing proposals are modified or extended. Emphasis is placed on the small number of different initial cyclisations of farnesyl pyrophosphate required to explain the biogenesis of the various skeletal types, and the key role of intermediates of the bisabolene and germacrane types is stressed. The published experimental studies on sesquiterpenoid biogenesis are reviewed and discussed. Experimental work on the biosynthesis in Artemisia maritima of the sesquiterpenoid bitter principle, santonin, is described. On the basis of the incorporations obtained, it is necessary to postulate two pathways for the later oxidative steps in its biosynthesis. These differ at the stage at which the first hydroxylation occurs. The incorporation of the ten-membered ring compound, 11,12-dihydrocostunolide suggests that this lactone is cyclised to a decalin system in the biosynthetic pathway. The incorporation of mevalonic acid lactone into santonin is shown to have occurred with scrambling of the label. Farnesyl pyrophosphate was not incorporated, while a very low incorporation of farnesol is recorded. The occurrence of 1,2—dihydrosantonin in Artemisia stellariana is proved. The isolation of the triterpenoid bitter principle, limonin,from the roots of Dictamnus albus is described. A low incorporation of mevalonic acid lactone into limonin is recorded.

Reversible addition-fragmentation chain transfer (RAFT) polymerisation has been used to synthesise a range of amphiphilic diblock copolymers. These diblock copolymers undergo polymerisation-induced self-assembly (PISA) to form spherical, worm-like or vesicular nano-objects, depending on the target diblock composition and the reaction conditions. These diblock copolymers are analysed by a variety of techniques including NMR, GPC, DLS and TEM.

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