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 ({ Eu -N} 2.559 Ǻ), and longer Eu -O bonds (av. 2.600Ǻ) trans to N than mutually trans ({ Eu -O} 2.553Ǻ). 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.