Tungsten(6+) Tris(pinacolate): Structure and Comments on the Preference for an Octahedral Geometry Relative to Trigonal Prismatic (D3h) for a d0 Complex in the Presence of Strong .pi.-Donor Ligands

The reaction between W(NMe 2 ) 6 and HOCMe 2 CMe 2 OH (pinacol, 3 equiv) in ether/hexanes yields the pale yellow compound W(OCMe 2 CMe 2 O) 3 (1) as pale yellow cubic crystals. Crystal data at -155 o C: a=16.841(2) A, b=9.878(1) A, c=13.373 (1) A, β=109.60 (1) o , Z=4, d calcd =1.69 g cm -3 , space group C 2 /c a crystallographically imposed C 2 axis of symmetry but may basically be described as having a distorted octahedral WO 6 core, W-O=1.92(1) A (average)