Organo-f-element chemistry with multidentate nitrogen ligands

Sm(Tp(Mc2)), undergoes one-electron-transfer reactions with a variety of reagents leading to mono- or dimetallic compounds, depending on the ligands. Reaction of Sm(Tp(Me2))(2) with fluorenone, benzophenone, benzaldehyde azine and phenantrenequinone gives monomeric Sm(Tp(Mc2))(2)X compounds. The radical anion nature of the coordinating ligands has been established by NMR and X-ray structural analysis. Reaction of Sm(Tp(Me2))(2) with less bulky ligands such as benzaldehyde or pyrazine leads to dimetallic [Sm(Tp(Me2))(2)](2)[mu-Y] compounds, where Y is the dianion formed by C-C coupling of two reductively eliminated ligands. The synthesis and reactivity of mono-ligated ytterbium(II) compounds with the sterically demanding Tp(Ms,R) (Tp(Ms,R)=[HB(3-Ms,5-Rpz)(3)]; Ms=mesityl, R=H, Me) and TPMs,R+ (Tp(Ms,R+) =[HB(3-Ms,5-Rpz)(2)(3-R,5-Mspz)]) ligands is also described. (C) 2002 Elsevier Science B.V. All rights reserved.