Tungsten Pair Formation in Tungsten Oxybromide Chemistry: The Crystal Structure of the One-Dimensional Ag0.37WOBr3

The oxytribromide Ag0.37WOBr3 crystallizes in the triclinic system: a = 3.766(3), b = 7.101(7), c = 10.49(1) Å, α = 101.80(5)°, β = 100.25(5)°, γ = 105.34(5)°, with the space group P1. The crystal structure determined from single crystal X-ray diffraction data is based on W2Br6 units, with short W-W distances, joined by W-O-W bonds to form [W2Br6O4/2]1∞ infinite chains developing along the a direction. Along the c direction, the cohesion between the chains is achieved by silver atoms which exhibit statistical distribution; along the b direction exist only van der Waals Br-Br contacts between adjacent chains. These weak linkages between the chains in two directions of the space give a strong one-dimensional character to this new tungsten oxybromide.