SYNTHESIS AND STRUCTURE OF MONO-THF SOLVATES OF BIS(CYCLOPENTADIENYL)SAMARIUM(II) COMPLEXES - (C5ME5)2SM(THF) AND [C5H2(SIME3)3][C5H3(SIME3)2]SM(THF)

X-ray crystallographic data have been obtained on the mono-THF solvates of the organosamarium(II) complexes (C5Me5)2Sm(THF) and [C5H2(SiMe3)3][C5H3(SiMe3)2]Sm(THF). (C5Me5)2Sm(THF) crystallizes from toluene in space group P2(1)/n with a 9.7606(13), b = 16.6557(17), c = 14.0710(16) angstrom, beta = 90.446(10)-degrees, V = 2287.4(5) angstrom3 and D(calcd) = 1.431 g cm-3 for Z = 4. Least-squares refinement of the model based on 2879 reflections converged to a final R(F) = 3.1%. {[C5H2(SiMe3)3][C5H3(SiMe3)2]Sm(THF)}C6H12)0.5 crystallizes from hexane in space group P1BAR with a = 9.3600(17), b = 11.0311(21), c = 20.4697(33) angstrom, alpha = 83.290(14), beta = 80.569(14), gamma = 88.785(15)-degrees, V = 2071.2(6) angstrom3 and D(calcd) = 1.225 g CM-3 for Z = 2. Least-squares refinement of the model based on 5988 reflections converged to a final R(F) = 3.1%. In these bent metallocenes, the THF oxygen atoms do not adopt the sterically least crowded positions and lie off the plane defined by the two ring centroids and the samarium by 1.54 angstrom for (C5Me5)2Sm(THF) and by 0.85 angstrom for [C5H2(SiMe3)3][C5H3(SiMe3)2]Sm(THF).