The syntheses of the unsymmetrical 14-membered bismacrolides have been reviewed. A total synthesis of clonostachydiol, the latest to join this family, has been attempted using trimethylsilyl acetylene as the builiding block and palladium catalyzed reactions for the formation of key bonds. The alkyne groups were introduced by Stille coupling of trimethylstannylethynyltrimethylsilane with an acid chloride for one fragment and by addition of lithiotrimethylsilyl acetylene to an aldehyde for the other. Lactic acid derivatives were chosen as starting materials for both fragments, thus introducing two of the chiral centers. The remaining stereocenters were introduced using stereoselective reductions of ketones.

A group of azabiphenyl complexes and supramolecules, and their reduced and oxidized forms when possible, were characterized by cyclic voltammetry and electronic absorption spectroscopy. The oxidized and reduced species, if sufficiently stable, were further generated electrochemically inside a specially designed quartz cell with optically transparent electrode, so that the spectra of the electrochemically generated species could be taken in situ. Assignments were proposed for both parent and product electronic spectra. Species investigated included a range of Ru(II) and Pt(II) complexes, as well as catenanes and their comparents. Using the localized electronic model, the electrochemical reduction can be in most cases assigned as azabiphenyl-based, and the oxidation as transition metal-based. This is consistent with the fact that the azabiphenyl compounds have a low lying π* orbital. The electronic absorption spectra of the compounds under study are mainly composed of π —> π* bands with, in some cases, charge transfer bands also.

As the miniaturization keeps decreasing in semiconductor device fabrication, metal contamination on silicon surfaces becomes critical. An investigation of the fundamental mechanism of metal contamination process on silicon surface is therefore important. Kinetics and thermodynamics of the copper out-plating process on silicon surfaces in diluted HF solutions are both evaluated by several analytical methods.

Precipitates of a series of alkaline earth metal (barium and strontium) carbonates, chromates, phosphates, and sulfates were formed at high supersaturation by diffusion through silica hydrogel, agarose hydrogel, and the freshly developed agarosesilica mixed gels. The reaction vessels could be a small test tube, a recently designed standard micro slide cassette and a enlarged supercassette. Homogeneous nucleation is thought to have taken place, and particle development led to the formation of an unusual category of materials, known as Induced Morphology Crystal Aggregates [IMCA], at high pH under far-from-equilibrium conditions. Standard procedures were developed in order to produce homogeneous gels. Particle development led to characteristic style of pattern formation, which I have called monster, spiral, and flake. Among these IMCA, barium carbonate, chromate, and sulfate were moderately easy to grow. Barium phosphate was very difficult to grow as IMCA due to formation of poorly crystalline spherulites. IMCA of strontium carbonate, chromate and sulfate could be developed at high basic pH in the presence of silicate. Strontium carbonate sheet morphology displays a unique property, double internal layer structure, which was identified by backscattering electron imaging (BEI). Selected electron diffraction (SAD) revealed a new crystal phase which was called "Dentonite". Precipitate particles were …

Part I. Reduction of the 1-methylpentacyclo [5.4.0.0²,⁶.0³,¹⁰,0⁵,⁹]undecane-8, 11-dione (9) with solid NaBH₄ resulted in highly stereoselective reduction of both C=O groups in the substrate, thereby affording the corresponding endo-8, endo-11-diol (11a). The configuration of 11a was established unequivocally by converting 11a into the corresponding cyclic thiocarbonate ester, 12. Part II. Z-1,2-Di(1'-adamantyl)ethene (14) was synthesized with a high degree of stereoselectively in four steps (Scheme 9 in Chapter 2). E-1,2-di(1'-adamantyl)ethene (15) was synthesized by iodine promoted isomerization of 14. Both structures were established unequivocally via single-crystal X-ray structural analysis. E-1-(exo-8'-Pentacyclo[5.4.0.0²,⁶.0³,¹⁰,0⁵,⁹]undecyl)-2-phenylethylene (16a) was synthesized, and its structure was established via analysis of its 1H, 13C, and 2D COSY NMR spectra. Part III. Reactions of electrophiles, i.e.,:CCl_2, PhSCl, and Br_2, to Z- and E-1,2-di(1'-adamantyl)ethenes (14 and 15, respectively) are described (Scheme 5, 8, 10, and 13 in Chapter 3). Structures of the corresponding products were established unequivocally via analysis of their respective one- and two-dimensional NMR spectra and/or single-crystal X-ray structural analysis. Part IV. An improved asymmetric synthesis of optically active (S)-4-hydroxy-2-cyclohexenone 1 (64%ee, determined via Mosher's method) has been developed (Scheme 5 in Chapter 4). The key step in this synthesis involves the baker's yeast reduction of 13. The absolute configuration of …

This work concerns some synthetic processes and basic properties of layered double hydroxides (LDHs). A series of LDHs, a family of newly developed materials found to have many potential uses in industry, were investigated in relating to the origin of life on early Earth. In this work, I successfully intercalated some inorganic as well as organic species. Ammonium, accompanied with ferrocyanide ion, can enter the layered space. It was found there were two kin go f intercalated ferrocyanide species: one is that exchanged with anions and became a part of layered double hydroxide, while the other is suggested to be related to ammonium ferrocyanide neutral species. Formaldehyde, ethanolamine and formate can also be involved into LDHs. To improve the crystallinity, homogeneous precipitation method, which used Urea and Hexamine, was employed. The results reveal the success in the case by Urea but not in that by Hexamine. Annealing could also be used for this purpose. However, it needs to be preocessed in its mother liquor; no improvement on the crystallinity if the material has been washed before annealing.