REACTIONS OF [WO2CL2(DME)] WITH TERT - BUTYLTRIMETHYLSILYLAMINE X-RAYSTRUCTURE OF [W(NBUT)2CL2(BUT-DAB)] (BUT-DAB=N,N'-DI-T-BUTYL-1,4-DIAZA-1,3-BUTADIENE)

[WO2Cl2(dme)] (dme = dimethoxyethane) reacts with 4 equivalents of Me3 SiNH(Be) to give different products depending on the solvent used. In n-hexane and dme as solvents the known complex {[W(NBUt)2Cl2(NH2BUt)]2 } was obtained, a monomeric derivative of which, [W(NBut)2Cl2(But-dab) ] (But-dab = N,N'-di-t-butyl-1,4-diaza-1,3-butadiene), has been charac terized by X-ray structure determination. The molecule has a distorted octahedral geometry with cis-butylimido ligands [W-N distances: 1.756 (8) and 1.758(8) angstrom; N-W-N angle: 105.9(4)-degrees] and trans-di chloro ligands [W-Cl distances: 2.389(2) and 2.394(3) angstrom; Cl-W-C l angle: 154.1(1)-degrees]. The bidentate Bu(t)-dab ligand is trans to the bisimido function; the W-N distances of But-dab are 2.507(7) and 2.533(7) angstrom and the N-W-N bite angle is 67.0(2)-degrees. In dime thylformamide (dmf) as a solvent a binuclear tungsten(VI) compound is formed. A structure with a linear N=W-O-W=N arrangement and three term inal trimethylsilanolato ligands at each tungsten atom, {[W2(NBUt)2(mu -O)(OSiMe3)6].dmf}, is suggested for this complex. This suggestion is based on elemental analysis, molecular weight determination, FAB mass spectroscopy, H-1, C-13, N-14, O-17 and Si-29 NMR IR and Raman spectro scopy.