Triphenylphosphineiminato-substituted tungsten(VI) fluorides. Crystal structure of tetrafluorobis(triphenylphosphineiminato)tungsten(VI)

The complexes [WF5L] and [WF4L2](L = Ph3PN) have been prepared from WF6 and LSiMe3; they are crystalline solids with high kinetic stability. A crystal structure determination of [WF4L2][space group Fdd2, a= 33.832(8), b= 18.933(4), c= 9.926(2)Å, Z= 8; R= 0.021] showed it to be the cis isomer with crystallographic 2 symmetry. The W–N bond length of 1.825 Å suggests multiplebond character. There is appreciable deviation from linearity at nitrogen (W–N–P 157.2°).