PREPARATION AND STRUCTURES OF ARYLMOLYBDENUM(6- (2,4,6-ME(3)C(6)H(2))(3)MO-N AND (2-ME(2)NCH(2)C(6)H(4))(2)((T)BUO)MO-N() NITRIDO COMPOUNDS)

((t)BuO)(3)Mo=N, 1, and the mesityl Grignard, MesMgBr, react in diethy l ether to give green solutions from which amber crystals of (Mes)(3)M o=N, 2, were obtained by crystallization from pentane/ether. In a rela ted reaction 1 and LiC(6)H(4)CH(2)NMe(2) (2 equiv) were found to yield (tBuO)(C(6)H(4)CH(2)NMe(2))(2)Mo=N, 3, which was also isolated as dar k amber crystals from ether/pentane. Compounds 2 and 3 have been cryst allographically characterized. In 2 there is a central pyramidal C3Mo= N moiety with Mo-N=1.649(4) Angstrom, Mo-C=2.125(5) Angstrom (av), and N-M-C=100 degrees. In 3 the coordination at molybdenum is that of a d istorted octahedron with Mo=N=1.620(22) Angstrom. The chelate C(6)H(4) CH(2)NMe(2) ligand forms five-membered rings and the N-Mo distance tra ns to the Mo=N bond is longer, cf. 2.742(2) Angstrom vs 2.434(2) Angst rom. These are the first crystallographically characterized metal nitr ides supported by hydrocarbyl ligands for a group 6 element and contra st with the recently reported ((t)BuCH(2))(3)Mo=N that was proposed to be polymeric [Herrmann; et al. J. Am. Chem. Sec. 1994, 116, 4989].