Bis[bis(triphenylphosphoranylidene)ammonium] Pentachlorofluoroosmate(IV) Hydrate, [(C₆H₅)₃P= N= P(C₆H₅)₃]₂[OsFCl₅].H₂O

The structure of the title compound, (C₃₆H₃₀NP₂)₂[OsCl₅F].H₂O, has been determined by single-crystal X-ray diffraction at 208 K. The octahedral [OsCl₅F]²⁻ complex anions are completely ordered in an A₂B-type lattice. The monoclinic unit cell contains four formula units, each with a solvent water molecule linked to the F ligand by a hydrogen bond [O...F 2.737 (8) Å]. The Os—F bond [1.960 (4) Å] is weakened by a trans influence and, correspondingly, the Os—Cl1 bond [2.307 (2) Å] trans to Os—F is strengthened compared with the average Os—Cl bond length along the Cl—Os—Cl axes of 2.339 Å.

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