EFFECTS OF METAL-SIZE AND AUXILIARY LIGAND ON THE ALKYLATION OF LANTHANIDE-HALIDE WITH LI[(CH2)(CH2)PPH(2)] - X-RAY CRYSTAL-STRUCTURES OF [ME(2)PPH(2)][SM(ETA(5)-C(5)H(4)BU(T))(3)CL] AND [LI(C4H8O)(4)][ER(NPH(2))(4)]

The interaction of Li[(CH2)(CH2)PPh(2)] in tetrahydrofuran with one eq uivalent of [(eta(5)-C(5)H(4)Bu(t))(2) LnCl . LiCl] (Ln = Sm, Yb) gave the anionic lanthanide are complex [Me(2)PPh(2)][Ln(eta(5)-C(5)H(4)Bu (t))(3)Cl] (1, Sm) or the neutral lanthanide-ylide complex [(eta(5)-C( 5)H(4)Bu(2)(t)Ln(Cl)CH2P(Me)Ph(2)] (3, Yb). The interaction of LnCl(3) (Ln = Er, Yb) in tetrahydrofuran with two equivalents of NaNPh(2) fol lowed by one equivalent of Li[(CH2) (CH2)PPh(2)] gave the unexpected a nionic homoleptic tetra-coordinate lanthanide-amide ate complex, [Li ( C4H8O)(4)][Ln(NPh(2))(4)] (4) Er; 5, Yb). All of these complexes have been characterized by analytical and spectroscopic methods. The struct ures of 1 and 4 have been established by X-ray diffraction. (C) 1997 E lsevier Science Ltd.