Unexpected outcome of the reaction of [(COD)2Rh2(μ-OH)2] with TREAT HF or 50% HF.: Peculiar structural features and diminished fluoride basicity of [(R3P)4Rh2(μ-F)2] (R = i-Pr, Ph)

The reaction of [(COD)Rh(mu-OH)](2) with TREAT HIP (Et,9N-3HF) or 50% HF in THF unexpectedly produced no Rh fluoride species but rather [Rh-3(mu-OH)(2)(COD)(2)]HF2 (1), in high yield. Single-crystal and powder X-ray diffraction studies established the structure of 1 and confirmed that the product was homogeneous in bulk. The structure of [(i-Pr3P)(4)Rh-2(mu-F)(2)] (X-ray) revealed a number of unexpected features pointing to a remarkably diminished basicity of the fluoro ligands.