| This thesis reports the design, synthesis and characterization of new gallium and indium compounds that are potential molecular precursors to gallium and indium nitrides. Forty-three new gallium and indium compounds with 21 being structurally characterized are reported.; The study on gallium nitride precursor chemistry, covered in Chapters 2–11, describes two approaches. One is to synthesize and characterize small gallium molecules that are potential low-temperature, carbon-free precursors (Chapters 2–6 and part of Chapter 11). The other is to synthesize and characterize gallium-nitrogen clusters that bridge the gap from small molecules to gallium nitride (Chapters 7–11).; In Chapter 2 a group of thermally robust mono- and dichlorogallium hydrides are reported, which have been demonstrated by the results reported in Chapters 3, 4 and 11 to be powerful starting materials to amido and azido gallium hydride compounds. The volatile, long shelf-life 1,1-dimethylhydrazidogallane is reported in Chapter 5, which is a promising, clean gallium source for depositing gallium-containing films. In addition to the gallium hydride chemistry, a silicon-carbon bond cleavage was discovered in the study of amido dichlorogallium precursors. The chemistry leading to understand the mechanisms is reported in Chapter 6.; Two synthetic routes were studied for gallium-nitrogen clusters. One method involving reactions between triorganylgallium and primary amines at elevated temperatures afforded a tetrameric and a heptameric imidogallane (Chapter 8). The second synthetic method, involving the reactions between hydrido-, alkyl- and phenyl dimethylamidogallium, [RGa(NMe 2)2]2, and primary amines, was developed for the synthesis of novel gallium-nitrogen clusters reported in Chapters 9–11. This method requires the use of a group of new reactants, [RGa(NMe2) 2]2, for which the synthesis and characterization are reported in Chapters 7 for R = Me, Et, nBu, nHx and Ph and 11 for R = H.; Our interest in indium chemistry is to synthesize all-nitrogen coordination compounds that are potentially carbon-free precursors to indium nitride. The synthesis and crystal structure of a monomeric indium hydrazide is reported in Chapter 12. It and several related amido compounds with long wavelength electronic absorptions were studied with the aid of ab initio calculations. |
