SYNTHESIS AND STRUCTURE OF ETA(1)-N-DIPHENYLDIAZOMETHANE COMPLEXES OFNIOBOLOCENE AND TANTALOCENE MONOHYDRIDES

Interaction of niobo- and tantalocene trihydrides (Cp2MH3; M = Nb, Ta) with diphenyldiazomethane under mild conditions leads to monohydride complexes of a new type, Cp2M(H) (eta1-NNCPh2), where M = Nb I and Ta II. I and II have been characterized by a H-1 NMR study, and I also by an X-ray single crystal diffraction study at 183 K (R = 0.029 for 151 0 reflections). The molecule of I is of a bent sandwich type with the distances Nb-Cp(plane) of 2.13 angstrom, Nb-N 1.850 angstrom (multiple bond), Nb-H 1.65 angstrom and H-Nb-N angle of 94-degrees.