Group 3 (Y) and 4f (largely Ce) metal(III) amides (largely 2,2,6,6-tetramethylpiperidinates) have been prepared and
structurally characterised: [Y(TMP)3] (1), [Ce(TMP)3(thf)] (2), [Li(thf)4][CeBr(TMP)3] (3), [{Y(TMP)2(m-OEt)}2]
(4), [{Y(TMP)2}2(m-OEt)(m-OBun)] (5), [{Ce(TMP)2(m-OEt)}2] (6) and [LaBr{N(SiMe3)(C6H3Pri
2-2,6)}2(thf)] (10)
[TMP ~ NC(Me)2(CH2)3C(Me)2]. Low yields of crystalline TeCl(TMP) (7) and [CeCl2(thf)5][TeCl5(thf)] (9) were
obtained from unsuccessful attempts to oxidise compound 2 by treatment with TeCl4. The compound Br(TMP)
(8), obtained from H(TMP) and N-bromosuccinimide, failed to react with tellurium. The X-ray structures of 1–7, 9
and 10 are reported. Such data for the TMP derivates 1–7 and 9 show significant differences from those of
N(SiMe3)2 analogues, largely because the TMP ligand is sterically more demanding.

J . M a t e r . C h e m . , 2 0 0 4 , 1 4 , 3 2 6 6 – 3 2 7 3