NUCLEAR-MAGNETIC-RESONANCE STUDIES ON PARTIALLY DEUTERIATED TRANSITION-METAL METHYL-DERIVATIVES

Nuclear magnetic resonance studies on [W(eta-C5Me4Et)(CH2D)4][PF6] show a strong temperature dependence of the isotope shift [delta(CH3) - delta(CH2D)] indicating the presence of a monoagostic methyl group. The magnitude and sign of the geminal coupling constant 2J(H-D) [and 2J(H-H)] and the isotope shift, together with the temperature dependence of this shift, have been recorded for [Ti(CH2D)Cl3], (Ti(CH2D)Cl3(dmpe)] (dmpe = Me2PCH2CH2PMe2), [Ta(CH2D)nCl5-n] (n = 1-3), [M(eta-C5H5)2(CH2D)2] (M = Ti, Zr or Hf), [M(eta-C5H5)2(CH2D)(thf)] [BPh4] (M = Ti or Zr, thf = tetrahydrofuran), (Ti(eta-C5H5)2(CH2D)F], [Zr(eta-C5H5)2(CH2D)(MeCN)2][BPh4], [Ti(eta-C5H5)(CH2D)3], [M(eta-C5Me4Et)(CH2D)3] (M = Ti, Zr or Hf) and [Y(eta-C5Me5)2(CH2D)(thf)]. The isotope shifts for all these complexes are essentially temperature independent. A convenient synthesis of Li(CH2D) is described.