A series of bis(η-cyclopentadienyl)uranium(III) dichloro-bridged-alkali-metal and dihalogenobis(η-cyclopentadienyl)uranate(III) complexes: single-crystal X-ray structure determination of [UCp″2(µ-Cl)2Li(pmdeta)] and [PPh4][UCp″2Cl2][Cp″=η-C5H3(SiMe3)2-1,3, pmdeta =(Me2NCH2CH2)2NMe]

Abstract

Reduction of [UCp″₂Cl₂] with either LiBuⁿ or Na–Hg in presence of the appropriate ligand L yields [UCp″₂(µ-Cl)₂M(L)_n][M = Li or Na, L_n=(thf)₂ or tmeda: or M = Li and L_n= pmdeta (5)], while addition of LiX in thf or [PPh₄]X in PhMe to [{UCp″₂(µ-Cl)}₂] gives [UCp″₂(µ-Cl)(µ-X)Li(thf)₂] or [PPh₄][UCp″₂(Cl)X][X = Cl (7) or Br]; X-ray and ¹H n.m.r. data on complexes (5) and (7) are compared with those for three other bis(η-cyclopentadienyl)-uranium(III or IV) or -uranate(III) chlorides having 2 p″s and 2 ls around U[Cp″=η-C₅H₃(SiMe₃)₂-1,3; thf = OC₄H₈, tmeda =(Me₂NCH₂)₂; pmdeta =(Me₂NCH₂CH₂)₂NMe)].