Bis(hydroxylaminato)-mono(pentamethylcyclopentadienyl) rare-earth metal complexes

Salt metathesis reactions involving the anhydrous rare-earth metal trichlorides MCl3 (M = Y, Ho, Er and Lu) and the N, N-diethylhydroxylaminato potassium salt, KONEt2 (1), and KC5Me5 result in formation of rare-earth metal hydroxylaminato complexes of the type [(C5Me5) M(mu-eta(1):eta(2)-ONEt2)-(eta(2)-ONEt2)](2) (M = Y (2a), Ho (2b), Er (2c) and Lu (2d)). Compound 1 was characterised by elemental analysis, compounds 2a and 2d by NMR spectroscopy and compounds 2a-d by elemental analyses, mass-spectrometry and single crystal X-ray diffraction. Compounds 2a-d are isostructural in the solid state. Effective saturation of the coordination sphere of the rare-earth metal atoms by the hydroxylaminato groups is achieved by the formation of three-membered MON rings.