A new ditungsten compound with a bridging ligand in a novel geometry,
W2Cl4(mu-dppm)(2)(eta(2)-mu-CH3CN) where dppm is bis(diphenylphosphino
)methane, has been prepared from a quadruply bonded starting material.
The structure of this compound is an example of a dinuclear tungsten
compound with an eta(2)-mu-bonded acetonitrile. The use of acetonitril
e as a solvent during the preparation of the known compound W2Cl4(mu-d
ppm), results in the incorporation of an acetonitrile molecule in a br
idging position with the C-N of this ligand perpendicular to the W-W a
xis. The bridging acetonitrile is no longer linear. The angle formed b
y the three-atom chain of acetonitrile, C-C-N, is 116.3(7)degrees with
a C-N bond distance of 1.303(8) Angstrom. The W-W bond distance is 2.
4981(10) Angstrom, significantly longer than the distance of 2.269(1)
Angstrom observed in the parent compound W2Cl4(mu-dppm). Crystallograp
hic data for this compound is as follows: P2(1)/c with a=12.577(5), b=
18.644(8), c=27.024(8) Angstrom, beta=95.98(2)degrees, V=6302(4) Angst
rom(3) and Z=4.