Organoamido- and Aryloxo-lanthanoids. I The Preparation and Characterization of Some Lanthanoid(II) Organoamides, and the X-Ray Crystal Structure of cis-Bis(carbazol- 9-yl)tetrakis(tetrahydrofuran)europium(II)

Reaction of carbazole (Hcbz) or 2-phenylindole (Hpin) with bis(pentafluorophenyl)-ytterbium or -europium in tetrahydrofuran (thf) gives the complexes M(cbz)₂(thf)4 (M = Yb or Eu) or Yb(pin)₂(thf)4. From treatment of lanthanoid metals with bis(pentafluorophenyl)mercury and 2-phenylindole, 2, 3, 4, 5-tetraphenylpyrrole (Htpp) or carbazole, the complexes M(pin)₂(thf)4 (M = Yb, Eu or Sm), M(tpp)2(thf)₃ (M = Yb or Sm) and Yb(cbz)2(thf)4 have been isolated. Desolvation of M(pin)₂(thf)4 under vacuum yields Yb(pin)₂(thf) and Sm(pin)₂(thf)3. Oxidation of Sm(pin)₂(thf)4 with Hg(C₆F₅)2 and 2-phenylindole gives Sm(pin)3(thf). The crystal structure of Eu(cbz)2(thf)4 shows the complex to be monomeric with distorted octahedral stereochemistry for europium, cis-carbazol-9-yl ligands ( 2·559 A), and longer Eu-O bonds (av. 2·600 A) trans to N than mutually trans ( 2·553 A). Other complexes M(NR2)₂(thf)_n (NR₂ =pin, cbz or tpp) are considered to be monomeric with five (n = 3) or six (n = 4) coordination.