The infra red, Raman and nuclear quadrupole resonance (n.q.r) spectra of several complexes of copper(I), silver(I) and gold(I) are reported. These are interpreted in terms of the structures of the complexes and the various possible bonding schemes for these d10 transition elements. To interpret the n.q.r. spectra the contributions to the field gradient at the copper nucleus of the various orbitals in the copper atoms are calculated and the Townes and Dailey approximations are revaluated. From this the s-d mixing theory of Orgel is chosen as the most satisfactory description of the bonding in these complexes. This theory is extended to cover several other geometries besides the D∞h geometry for which it was originally derived.

This thesis describes the single crystal x-ray analyses of six novel organometallic osmium complexes and three complexes of the tridentate dentate ligand 1,6-bis(diphenylphosphino)-trans-hex-3-ene with the transition metals iridium, rhodium and ruthenium. The complexes of carbon monosulphide and carbon monotelluride with osmium, OsCl2(CO)(CS)(PPh3)2 and OsCl2(CO)(CTe)(PPh3)2, exhibit linear thio- and telluro-coordination similar to that of the carbonyl. The -CS and -CTe ligands exert strong trans-bond weakening influences. In the dihapto-thioacyl complex of osmium, Os(η1-o2CCF3)[C(S)-(p-tolyl)](CO)(PPh3)2, the bidentate thioacyl is coordinated to the osmium through the carbon and sulphur atoms. This bonding involves a considerable degree of π-interaction between the C, S and Os atoms, concomitant with a lengthening of the C-S bond. The dichlorocarbene complex, OsCl2(CO)(CCl2)(PPh3)2 is disordered in the crystalline state. Consequently, while the presence of the dichlorocarbene is verified, no unambiguous conclusions can be drawn from the associated geometry. In the carbyne complex of osmium, Os(C-p-tolyl)Cl(CO)(PPh3)2, the osmium is in a trigonal bipyramidal environment with an approximately linear arrangement of the Os-C-R group. The Os-Ccarbyne bond is short (corresponding to a bond order of ca. 3), confirming the formation of the C-p-tolyl group as a carbyne. The formaldehyde ligand in the osmium complex, Os(η2-CH2O)(CO)2(PPh3)2, is bonded to the osmium centre via both the carbon and oxygen atoms. The C-O bond of the formaldehyde lengthens considerably upon coordination, resulting in a bond order apparently less than 1. Also present in the crystal structure are molecules of water which are hydrogen bonded into pairs (O…O separation 2.56 Å). The (H2O)2 units do not hydrogen bond to any other atoms, but rather occupy hydrophobic interstices in the structure. The three complexes of 1,6-bis(diphenylphosphino)-trans-hex-3-ene, (BDPH), IrIIICl3(BDPH), RhIIICl3(BDPH), and RuIICl2(CO)(BDPH) are isomorphous. The ruthenium complex is, however, disordered in the crystalline state. In each of the three structures the olefin of the BDPH moiety is only weakly bound to the metal, leaving the C-C double bond virtually unchanged from that of the free ligand. The olefin exerts a stronger trans-bond weakening influence than do the chlorine ligands in these complexes.

This thesis is concerned with a study of the oxidation of ring-A aromatic steroids using either chromium trioxide-aqueous sulphuric acid-acetone or chromium trioxide-aqueous acetic acid mixtures. It was found that chromic acid oxidation of ring-A aromatic steroids substituted with a strong electron-donating group, gives rise to products with the site of oxidation being predominantly that para to the activating group. Thus C-3 methoxy ring-A aromatic steroids give the corresponding 9b-hydroxy-11-oxo and 9-oxo-9,11-seco-11-oic acid derivatives as the major products and the 6-oxo derivative as a minor oxidation product. However, a ketol was not formed if a C-3 methoxy ring-A aromatic steroid also contained a substituent at C-1. The C-1-methoxy-4-methyl ring-A aromatic steroids give the 4-carboxy derivative as the major product and again the 6-oxo compound as a minor neutral product. The acetoxy and methyl substituted ring-A aromatic steroids, however, all give rise to the 6-oxo derivatives as the major products. The usual oxidation product of a ring-A aromatic steroid is therefore the 6-oxo product unless it is substituted with a methoxy group in a position which will stabilise an electron deficiency at a site other than C-6. Oxidation will then occur predominantly at the stabilised site unless it is sterically blocked.

The modified reactivity observed when a substituted arene is complexed to a cycIopentadienylruthenium moiety has been exploited to prepare a range of synthetically interesting target molecules. Activation of nitrogen- and halogen- substituted arenes has been achieved by compIexation to the cyclopentadienylruthenium moiety. Double nucleophilic substitution reactions between substituted (7 6- 1,2-dichlorw benzene)RuCp+ salts and substituted 1,2-benzenediols were carried out under mild conditions to prepare substituted (q6-dibenzodioxin)ruthenium complexes. Both mono- and di-substituted dibenzodioxin complexes were prepared. The dibenzodioxin ligands were subsequently liberated by photolysis. The complexation of a range of substituted benzimidazoles to the cyclopentadienylruthenium moiety has been studied. Several complexes were isolated and structures proposed. The metal moiety has been used to influence the stereoselection achieved in the reduction of carbonyl substituted arenes. A number of keto-arene complexes were prepared and reduced with sodium borohydride. The resulting alcohol complexes were characterised and the observed diastereoselectivity rationalised. Yanovsky-like adducts were prepared by nucleophilic addition to the cationic ruthenium salts to produce neutral (n5-cyclohexadienyl)ruthenuim complexes. A comparison between lithium, silicon and tin enolates was undertaken.

Polarographic chemical analysis, although invented only twenty-five years ago, has already become a standard method ror the research worker and industrial analyst alike. The variety or topics in pure, bio- and commercial chemistry which may be investigated easily with the polarograph, as well as its application to microchenistry, has found it a place in laboratories throughout the world. The invention offthe method, and much or the pioneer development are due to Jaroslav Heyrovsky and his colleagues at Charles University, Prague, (Phil. Mag., 1923, 45, 303; Trans. Faraday Soc., 1923, 19, 692 et seq.) Kucera, also of Charles University, noticed peculiar inflections in the electrocapillary curve of mercury under certain conditions, and devised the "dropping mercury electrode", now commonly used; to investigate these, (Ann. Physik., 1903,11, 529). Further work on this subject by Heyrovsky led ultimately to the development of polarography, (Ohemo Listy, 1922, 12, 256.)

2-Oxonanoyl oxide (27) has been converted to the 2-hydroxy ether (65) and the 2-oxo ether (66) both of which Possess ambergris-type odours similar to that of the odiferous compound (1). The route which affords the highest yield is via the intermediates (64), (75), (43) and (36), and this gives 23% of the 2-oxo ether (66) and 17% of the hydroxy ether (65) from 2-oxomanoyl oxide. A two-step transformation of manoyl oxide (26) into the Perfume (1) has been achieved by oxidising manoyl oxide with chromium trioxide in acetic acid, and then reducing the resulting lactone (55) directly to its cyclic ether (1). Attempts were made to synthesise new ambergris-type perfumes, and successful preparation of the internal ketal (108) showed that contrary to expectations this ketal is odourless. Comparison of the mass spectra of the lactones (54), (55), (56), and (145), with those of their c8 epimers (57), (58), (59), and (146) respectively, showed that the trans-fused lactones lose carbon dioxide upon electron-impact while the cis-fused isomers do not.

Following the classical work of Werner whose co-ordination theory provided the first rational foundation for the study of transition metal complexes, chemists have endeavoured to discover the underlying principles involved in these compounds. Thus, while Werner noticed the directional property of the bonds between metal and ligand, it was not until Pauling (1931) and others were able to apply a wave mechanical treatment, that an explanation for the rigid stereochemical requirements of the metal was found. With this growth in fundamental knowledge the interpretation and use of the physical properties of complex compounds has become possible. For example, the magnetic susceptibility has been related to the electronic configuration of the metal atom, (Pauling loc. cit.) enabling predictions to be made about the type of metal-ligand bond.

The crystal structures of four coordination compounds of copper(II) have been investigated by three-dimensional X-ray methods. The structure of one crystalline form of bis-(N-ethyl-salicylaldiminato) copper(II) has revealed that the copper atom in such a compound may adopt a tetrahedrally-distorted coordination geometry under less severe steric conditions than had previously been supposed. The structures of a methylamine perchlorate adduct of NN’-ethylenebis-(acetylacetoneiminato) copper(II) and p-nitrophenol and chloroform adducts of NN’-ethylenebis-(salicylaldiminato) copper(II) have indicated that the bonding requirements of the copper atom can be modified by hydrogen bonding involving a ligand atom.

The first part of this thesis is concerned with the structure, stereochemitry, and reactions of asperuloside, a labile glucoside widely distributed among plants of the family Rubiaceae. Its interest to this Departmen arose from its abundant, occurrence in Coprosma species, most of which are native to New Zealand. Since the aglycone of asperuloside is now known to possess the carbon skeleton (1) , asperuloside may be formally regarded as monoterpenoid. This Introduction therefore considers the structures, interrelationships, and biogenesis of cyclopentanoid monoterpenoids possessing the 1,2-dimethyl-3-isopropylcyc clopentane carbon skeleton (1). Cyclopentanoid Monoterpenoids: Although acyclic and cyclohexanoid monoterpenoids have been characterised for nearly eight years, naturally occurring compounds possessing the carbon skeleton (1) have been defined relatively recently. Despite their frequently unusual chemical behaviour and physiological actions, which have often been recorded in the early literature, progress in the elucidation of their structures has awaited the application of modern physical techniques. The carbon skeletons are frequently highly oxygenated, and the characteristic chemistry of the compounds arises from the interactions of contiguous functional groups. Since the chemistry of the type compounds, nepetalactone (2), iridomyrmecin (3), and iridodial (4) has been reviewed, only more recent work will be discusse below.

The crystal structure of bis-(pyridoxylidene-L-valine)nickel(II) hydrate (referred to as nickel(II) pyridoxylidene L-valine) has been determined but the difficulty in detecting small deviations from body-centred symmetry, and in locating all solvent molecules, has precluded an accurate analysis. Octahedral coordination to the nickel atom is achieved by the attachment of two Schiff base units. The fused ring system of each unit reveals distortions from planarity.