Oxidative elimination of H{sub 2} from [Cp`{sub 2}U({mu}-OH)]{sub 2} to form [Cp`{sub 2}U({mu}-O)]{sub 2}, where Cp` is 1,3-(Me{sub 3}C){sub 2}C{sub 5}H{sub 3} or 1,3-(Me{sub 3}Si){sub 2}C{sub 5}H{sub 3}
- Lawrence Berkeley Lab., CA (United States)
This paper describes the unprecedented thermal decomposition reaction of a dimeric metal hydroxide shown in an equation. Since the net transformation involves elimination of hydrogen along with oxidation of the uranium metallocene from U(III) to U(IV), the reaction is an oxidative elimination. While examining the variable-temperature {sup 1}H NMR spectra of I-OH, we noticed that this compound decomposes at a reasonable rate at 100{degree}C to give a new set of resonances due to a U(IV) metallocene. The new resonances are due to the dimeric uranium oxide compound Cp{sub 4}U{sub 2}({mu}-O){sub 2} (I-O), as shown by independent synthesis. The elimination of H{sub 2} from two hydroxide ligands at first glance seems thermodynamically unreasonable since, in the first step of the reaction, an O-H bond of 119 kcal/mol is broken and a U-H bond of nearly 60-80 kcal/mol is formed. However, both uranium atoms are oxidized from U(III) to U(IV) in the first step of the net reaction. Since this oxidation potential is nearly 1.8 V, the oxidation adds about 80 kcal/mol to the reaction. 17 refs., 2 figs., 1 tab.
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 232480
- Journal Information:
- Journal of the American Chemical Society, Vol. 118, Issue 4; Other Information: PBD: 31 Jan 1996
- Country of Publication:
- United States
- Language:
- English
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