Preparation and characterization of compounds containing the octamethylditungsten(II) anion and partially chlorinated analogs

X-ray crystallographic structural studies of the quadruply bonded octamethylditungsten anion and a related species containing a mixture of chloro and methyl ligands

“…Compounds 1 and 2 were prepared by procedures previously described. 2 We also prepared, crystallized, and examined by X-ray diffraction the compound Li4W2(CH3)8-4THF. We never succeeded in obtaining fully satisfactory crystals of this substance.…”

“…It is also quite reasonable when it is compared to the structures of the other M2(CH3)8 anions, as will be shown in the Discussion. Crystal Data and Structure Determination7 for Li4W2-(CH3)XC18_X4THF (2). A red crystal measuring about 0.2 X 0.2 X 0.2 mm was sealed in a glass capillary in mineral oil, immediately cooled to -55 °C, and examined on a Syntex Pi four-circle automatic diffractometer equipped with a Syntex LT-1 low-temperature attachment.…”

“…However, we have recently succeeded in obtaining some acceptable crystals of one of them. We are, therefore, reporting fully on our structural studies of the compounds Li4W2(CH8)-4Et20 (1) and Li4W2-(CH3)xC18_v4THF (2).…”

“…Only for this last compound had it been possible to obtain crystallographic data up to the time of our earlier report,1 and this has been reported in a preliminary note. 2 The compounds containing only methyl groups proved very difficult to crystallize in forms suitable for single-crystal X-ray structure analysis. However, we have recently succeeded in obtaining some acceptable crystals of one of them.…”

A new mixed-ligand complex of the quadruply bonded ditungsten unit bis(N,N'-diphenylacetamidinato)bis(2,4-dimethyl-6-hydroxypyrimidinato)ditungsten bis(tetrahydrofuranate)

“…The structure was solved8 in the monoclinic space group P2¡/n. The position of the one crystallographically independent tungsten atom was found by solution of the three-dimensional 6) 8 (1) 0.4 (5) 1.5 (7) 0.9 (7) C (6) 0.324 (2) -0.088 (2) 0.5334 (11) 9 (1) 1.7 ( 7) 6 (1) -2.6 (7) 10) 7 (1) 7 (1) 3.3 (8) 0(1) 4.0( 7) 5 (1) and a goodness of fit parameter of 1.272. The function £>v(|F0| -IC-I)1/2 was minimized with the weighting factor, tv, equal to 4F02/ a{F2)2.…”