The influence of oxygen on the wetting of sapphire (α-Al₂O₃) by liquid copper was investigated using the sessile drop technique in vacuum at 1230°C. For additions to copper of cupric oxide, varying from 1 – 72% of the copper weight, chemical reaction at the liquid-solid interface resulted in spreading of the liquid and a rapid decrease of the contact angle to a steady state value. A direct relationship between the fourth power of the basal radius of the molten drop and the oxygen present was observed. The product of the interfacial reaction was found to be CuAlO₂. Phase diagrams of the systems CuO-Al₂O₃ and Cu₂O-Al₂O₃ were determined experimentally using X-ray diffraction techniques for identification of the phases. The aluminates, Cu(AlO₂)₂ and-CuAlO₂ were identified and their ranges of stability in air established. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

A plethora of novel scientific phenomena and practical applications, such as solid-state molecular solar cells and other optoelectronic devices for energy harvesting and lighting technologies, have catalyzed us to synthesize novel compounds with tunable properties. Synthetic routes, single crystal structures, and spectral and materials properties are described. Reactions of Ag(I) and Cu(I) precursors with various types of ligands -- including the azolates, diimines, and diiphosphines -- lead to the corresponding complexes in high yield. Varying the metal ions, ligands, synthetic methods, solvents, and/or stoichiometric ratio can change the properties including the molecular geometry or packing structure, reactivity, photophysical and photochemical properties, semiconducting behavior, and/or porosity of the functional coordination polymers obtained. For solar cells purposes, the absorption energy can be extended from the ultraviolet (UV) region, through the entire visible (Vis) region, onto a significant portion of the near-infrared (NIR) portion of the solar spectrum with high absorption coefficients due to the infinite conjugation of Cu(I) with diimine ligands. Twenty-eight crystal structures were obtained by conventional crystal growth methods from organic solvents, whereas their bulk product syntheses also included "green chemistry" approaches that precluded the use of hazardous organic solvents. The resulting products are characterized by powder x-ray diffraction (PXRD), Fouriertransform infrared (FTIR), nuclear magnetic resonance (NMR), UV/Vis/NIR absorption/diffuse reflectance/photoluminescence spectroscopies, and thermogravimetric analysis (TGA). Regarding the scientific phenomena investigated, the highlighting work in this dissertation is the discovery of novel bonding/photophysical/optoelectronic properties of the following materials: a black absorber with absorption from 200- 900 nm, a very stable compound with a bright green luminescence obtained by a solventless reaction, and a novel coordination polymer showing uncommon interaction of Ag(I) with three different types of diimine ligands simultaneously.