Organometallic uranium(iv) fluoride complexes: preparation using protonolysis chemistry and reactivity with trimethylsilyl reagents

Abstract

Reaction of the uranium alkyl complex (C₅Me₅)₂UMe₂ (1) with Et₃N·3HF in toluene in the presence of a donor ligand (pyridine or trimethylphosphine oxide) results in gas evolution and the formation of the uranium(IV) difluoride complexes (C₅Me₅)₂UF₂(L) (L = NC₅H₅ (2), Me₃PO (3)). Similarly, reaction of (C₅Me₅)₂U[κ²-(C,N)-CH₂Si(CH₃)₂N(SiMe₃)] (5) with Et₃N·3HF in toluene gives the uranium(IV) amide-fluoride complex (C₅Me₅)₂U[N(SiMe₃)₂](F) (6). The fluoride complex (C₅Me₅)₂UF₂(NC₅H₅) (2) shows versatile reaction chemistry with a variety of trimethylsilyl reagents and demonstrates that the U–F bond provides an attractive synthetic strategy for accessing new functional groups that are not available from alkoxide or chloride complexes.