摘要:
Metathesis of Me2GeCl2 or Me2SnCl2 with 2 equiv of LiC5Me4H affords Me2Ge(C5Me4H)2 (1) and Me2Sn(C5Me4H)2 (2), respectively. The subsequent deprotonation of 1 with MeLi yields only the desired dilithium salt Me2Ge(C5Me4Li)2 (3) whereas 2 forms Me4Sn and two LiC5Me4H. The trichlorides of neodymium, samarium, holmium, and lutetium react with the dilithium salt 3 with the formation of Me2Ge(C5Me4)2LnCl2Li(THF)2 (Ln = Nd (4), Sm (5), Ho (6), Lu (7)). The reaction of 4 and 6 with LiCH(SiMe3)2 produces Me2Ge(C5Me4)2LnCH(SiMe3)2 (Ln = Nd (8), Ho (9)). The new compounds have been characterized by elemental analysis, mass and NMR spectra, as well as X-ray structural analysis of 5, 7, and 9. The halides 5 and 7 crystallize in the monoclinic space group P2(1)/c (No. 14) with a = 9.7284 (9), b = 19.397 (1), c = 16.610 (2) angstrom, beta = 98.963 (9)-degrees; Z = 4 or a = 9.578 (3), b = 19.218 (4), c = 16.525 (4) angstrom, beta = 99.73 (2)-degrees; Z = 4, respectively. Least-squares refinement led to a final R value of 0.020 (F(o) > 4-sigma-(F(o))) for 5554 independent reflections for 5 or of 0.028 (F(o) > 3-sigma-(F(o))) for 5822 independent reflections for 7. Compound 9 crystallizes in the monoclinic space group P2(1)/m (No. 11) with a = 9.2621 (8), b = 14.216 (2), c = 11.839 (2) angstrom, beta = 107.79 (1)-degrees, Z = 2, and R = 0.023 (F(o) > 4-sigma-(F(o))) for 2954 reflections. The structure of 9 shows a short Ho-C(methyl) contact of 2.774 (4) angstrom.