Synthesis and Structure of [{Mo(CO)(4)}(2)(cis-&mgr;-F(2)SbF(4))(3)](x)()[Sb(2)F(11)](x)(): An Ionic Coordination Polymer.

The oxidation of molybdenum hexacarbonyl, Mo(CO)(6), by antimony(V) fluoride, SbF(5), at 60 degrees C in an excess of liquid SbF(5), produces polymeric [{Mo(CO)(4)}(2)(cis-&mgr;-F(2)SbF(4))(3)](x)()[Sb(2)F(11)](x)() as the main product. Recrystallization from HF-SbF(5) produces orange prismatic crystals, suitable for a single-crystal X-ray diffraction study. Crystals of [{Mo(CO)(4)}(2)(cis-&mgr;-F(2)SbF(4))(3)](x)()[Sb(2)F(11)](x)() are monoclinic, space group P2(1)/c (No. 14), a = 9.234(4) Å, b = 13.858(3) Å, c = 25.790(3) Å, beta = 90.532(2) degrees, V = 3300.1(12) Å(3), and Z = 4. The structure was solved by the Patterson method and refined with anisotropic thermal parameters to R = 0.048 and R(w)() = 0.047 (on F, 472 variables, 5116 observations with I >/= 3sigma(I)). In the polymeric cation, two pyramidal Mo(CO)(4) groups are linked by bridging, iso-bidentate F(2)SbF(4) groups first into eight-membered rings, which are then further linked into polymeric chains. The bridging F(2)SbF(4) groups and the [Sb(2)F(11)](-) anion are involved in significant intermolecular and interionic F.C contacts to the C atoms of the Mo(CO)(4) groups.