NEW MIXED-LIGAND COMPLEX OF THE QUADRUPLY BONDED DITUNGSTEN UNIT - BIS(N,N'-DIPHENYLACETAMIDINATO)BIS(2,4-DIMETHYL-6-HYDROXYPYRIMIDINATO)DITUNGSTEN BIS-(TETRAHYDROFURANATE)

Reaction of W2(dmhp)4(dmhp=the anion of 2,4-dimethyl-6-hydroxypyrimidine) with the lithium salt of N,N'-di-phenylacetamidine, Li[(PhN)2CCH3], has given a product in which two dmhp ligands have been replaced, in transoid fashion, by two [(PhN)2CCH3] ligands. This red crystalline product, W2(dmhp)2[(PhN)2CCH3]2-2THF, is air sensitive but thermally stable. It is only sparingly soluble in several common solvents and insufficiently volatile to give a mass spectrum under the usual conditions. It crystallizes in space group P21/m with Z=2, thus requiring the molecules to lie on crystallographic inversion centers. The W-W distance 2.174 (1) A is very similar to that in W2(dmhp)4. The unit cell dimensions are a=11.399 (3) υ, b= 10.431 (1) A, c=20.002 (4) A, υ=101.9 (3)°, and V= 2327.4 (1.5) υ3. The structure has been refined to R1=0.039 and R2=0.053 by using anisotropic.thermal parameters for all atoms except those in the THF molecule. © 1979, American Chemical Society. All rights reserved.