Inorganic Chemistry, Vol.37, No.1, 112-119, 1998
Synthesis and structure of a zirconium dinitrogen complex with a side-on bridging N-2 unit
Reduction of Zr(O-2, 6-Me2C6H3)Cl-2[N(SiMe2CH2PPr2i)(2)] with sodium amalgam under dinitrogen yields the dinuclear zirconium dinitrogen complex {[((Pr2PCH2SiMe2)-P-i)(2)N]Zr(O-2, 6-Me2C6H3)}(2)(mu-eta(2):eta(2)-N-2). Solid state structural analysis shows that the dinitrogen unit is bound in a side-on mode of coordination with the N-N bond distance at 1.528(7) Angstrom; resonance Raman spectra show a band at 751 cm(-1) for v(N-N), which is consistent with this very long bond. In addition, the N-2 ligand is hinged slightly so that the Zr-2(mu-eta(2):eta(2)-N-2) core adopts a flattened butterfly shape rather than a completely planar core as found in other related systems. Other Zr(IV) precursors of the general formula ZrCl2X[N(SiMe2CH2PPr2i)(2)] (X = OBut, OCHPh2, NPh2) either decompose upon reduction under N-2 or produce mixtures of products.
Keywords:TRANSITION-METAL COMPLEXES;X-RAY;CRYSTAL-STRUCTURES;NITROGEN-FIXATION;END-ON;CHEMISTRY;LIGAND;ACTIVATION;REDUCTION;CLEAVAGE