Portal de Periódicos da CAPES

Preparation and Reactions of Base-Free Bis(1,2,4-tri- tert -butylcyclopentadienyl)uranium Oxide, Cp‘ 2 UO

2005; American Chemical Society; Volume: 24; Issue: 17 Linguagem: Inglês

10.1021/om050406q

1520-6041

Guofu Zi, Jia Li, Evan L. Werkema, Marc D. Walter, J. Gottfriedsen, Richard A. Andersen,

Radiopharmaceutical Chemistry and Applications

Reduction of the uranium metallocene [η5-1,2,4-(Me3C)3C5H2]2UCl2 (1), Cp'2UCl2, in the presence of 2,2'-bipyridyl and sodium naphthalene gives the dark green metallocene complex Cp'2U(bipy) (6), which reacts with p-tolyl azide or pyridine-N-oxide to give Cp'2UN(p-tolyl) (7) or Cp'2U(O)(py) (8), respectively. The Lewis acid BPh3 precipitates Ph3B(py) and gives the base-free oxo Cp'2UO (10), which crystallizes from pentane. The oxometallocene 10 behaves as a nucleophile with Me3SiX reagents, but it does not exhibit cycloaddition behavior with acetylenes, suggesting that the polar resonance structure Cp'2U+−O- dominates the double-bond resonance structure Cp'2UO.