Date of Award
Doctor of Philosophy
Robert E. McCarley
Low temperature routes were used to synthesize tungsten and molybdenum nitride precursors from metal chlorides and nitrogen-containing compounds. A number of reactions in ammonia and organic solvents were undertaken to prepare tungsten and molybdenum nitrido precursors. These compounds were then treated at moderate temperatures (200-500°C) to form the nitride compounds. During the heat treatment of one of the precursors, a tungsten imide bronze species was discovered. A Reitveld refinement of the x-ray powder data was performed and the structure was found to be similar to the Rb[subscript]0.27WO[subscript]3 tungsten bronze (Magneli A; Acta Chem. Scand. 1953, 7, 315);The syntheses of NdMo[subscript]8O[subscript]14 and some of its rare earth analogues were performed at high temperatures in sealed molybdenum and fused silica tubes. The structure of NdMo[subscript]8O[subscript]14 contains discrete bicapped octahedral cluster units, but the cluster units are interconnected in such a way that a relatively short intercluster Mo-Mo distance of 3.059 A results. Magnetic susceptibility and resistivity measurements indicated an interaction between the cluster units which leads to electron delocalization and metallic character. These data thus indicate that the short intercluster distance represents a bonding interaction;Large single crystals of the intermetallic compounds Ni[subscript]2.43Fe[subscript]4.57Mo[subscript]6 were observed as products in a high temperature reaction which involved various oxygen containing species. The compound was found to be similar to Co[subscript]7Mo[subscript]6 (Forsyth, J. B; d'Alta de Veiga, L. M; Acta Crystallogr. 1962, 15, 433). The single crystal x-ray refinement shows that the compound is composed of layers of molybdenum and mixed layers of nickel and iron. Very short metal-metal distances were observed in the compound.
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Clark Dale Carlson
Carlson, Clark Dale, "The synthesis and characterization of some tungsten nitrides and reduced molybdenum oxides " (1989). Retrospective Theses and Dissertations. 9112.