Reactivity of dicyclopentadienyluranium(IV) derivatives: formation and structural characterization of an oxygen bridged cluster containing both inorganic and organometallic uranium atoms

Reactions of [U(Cp)2(NEt2)2] (Cp = ?5-cyclopentadienyl) and [U(Cp)2(BH4)2] with LiAlH4 in diethyl ether give [U(Cp)2(AlH4)2NEt2]Li (1) and [U(Cp)2(AlH4)2]·nEt2O (2), respectively. Reaction of 2 with CH3COOH gives a low yield of the cluster [Cp(CH3COO)5U2O]2 (3), whose crystal structure is reported. Complex 3 is a centrosymmetric tetranuclear dimer in which two Cp(CH3COO)5U2O moieties are connected by chelating carboxylato and oxide bridges. A peculiarity of 3 is the presence of two oxygens each of them bridging three uranium atoms.