Synthesis and characterization of homo- and hetero-metallic coordination compounds and oxide nanostructures
Author
Hofmann, Cristina
Date
2008Advisor
Whitmire, Kenton H.
Degree
Doctor of Philosophy
Abstract
This dissertation combines coordination and materials chemistry studies. The oxide materials and nanoparticles formed are produced from decomposition of known or brand new coordination compounds.
Chapters I and II discuss the synthesis, characterization, and functionalization of shaped nanoparticles. Fe(II)(O2CH)2 and Mn(II)(O 2CH)2 were used as precursors for the controlled synthesis of wustite (FexO), manganosite (MnO), and iron-manganese (Fe 1-yMnyO) nanocrystals with non-thermodynamic shapes, such as concave cubes, nanocrosses, and 'dogbones'. An acid-base surfactant system under thermal conditions and atmospheric pressure was employed. The nanoparticle morphology was studied as a function of reaction parameters, of which water and surfactants were found most critical for shape control. Shaping progress is described as a function of crystal defects and dissolution-precipitation processes. Nanoparticles were successfully oxidized to the magnetic phases, Fe3O4 (magnetite) and Mn3O4 (hausmannite), while retaining original shape. Iron oxide-gold and manganese oxide-gold nanoshells were produced, and these maintained the magnetic behavior of magnetite and hausmannite, as demonstrated by magnetic measurements.
Keyword
Inorganic chemistry; Engineering; Materials science