Graduate Thesis Or Dissertation

 

New Synthetic Approaches to Chromium Dioxide and Synthesis of Group 4 Organometallics Supported by β-Diketonate Ligands Public Deposited

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https://scholar.colorado.edu/concern/graduate_thesis_or_dissertations/b8515n808
Abstract
  • CrO2 is a half-metallic ferromagnet, with calculations suggesting that all spin up electrons are conductive while all spin down electrons have a band gap of 1.6 eV. Current state of the art synthetic routes cannot create pure CrO2 materials, and the impurities impede the 100% spin polarization that makes CrO2 unique. Here, we attempted a sol-gel synthesis of CrO2 from CrIV precursors and H2O, similar to the approaches used to synthesize TiO2. CrO2 was formed without high temperatures, oxygen pressures nor the use of CrVI precursors, but pure materials were not achieved. Additionally, using a sterically encumbered β-diketonate, we report the synthesis of Ti(ArAcac)2Bn(THF) and M(ArAcac)2Bn2 (M = Zr, Hf). The reaction of H(ᴬʳAcac) (HArAcac = 1-tBu-3-(2,4,6-Me3C6H2)C6H3))(1,3-pentanedione) with MCl4 (M = Zr, Hf) gives M(ArAcac)2Cl2 in 84% and 78% yield, respectively. When treated with 2 equivalents of BnMgCl, the corresponding dibenzyl complexes M(ArAcac)2Bn2 are formed.

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  • 2018
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  • 2020-02-03
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