The Kinetics of Dissociations of Aluminum - Oxygen Bonds in Aqueous Complexes - An NMR Study [electronic resource].
- Davis, Calif. : University of California, Davis, 2003.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 4 pages : digital, PDF file
- Additional Creators:
- University of California, Davis
United States. Department of Energy. Office of Scientific and Technical Information
- OAK B262 The Kinetics of Dissociations of Aluminum--Oxygen Bonds in Aqueous Complexes--An NMR Study. In this project we determined rates and mechanisms of Al(III)-O bond rupture at mineral surfaces and in dissolved aluminum complexes. We then compared the experimental results to simulations in an attempt to predict rate coefficients. Most of the low-temperature reactions that are geochemically important involve a bonded atom or molecule that is replaced with another. We probe these reactions at the most fundamental level in order to establish a model to predict rates for the wide range of reactions that cannot be experimentally studied. The chemistry of small aluminum cluster (Figure) provides a window into the hydrolytic processes that control rates of mineral formation and the transformation of adsorbates into extended structures. The molecule shown below as an example exposes several types of oxygens to the bulk solution including seven structurally distinct sets of bridging hydroxyls. This molecule is a rich model for the aqueous interface of aluminum (hydr)oxide minerals, since it approaches colloidal dimensions in size, yet is a dissolved complex with +18 charge. We have conducted both ¹⁷O- ²⁷Al- and ¹⁹F-NMR experiments to identify the reactive sites and to determine the rates of isotopic exchange between these sites and the bulk solution. The research was enormously successful and led to a series of papers that are being used as touchstones for assessing the accuracy of computer models of bond ruptures in water.
- Published through SciTech Connect.
Dr. William Casey.
- Type of Report and Period Covered Note:
- Final; 09/03/2003 - 09/03/2003
- Funding Information:
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