95464-85-0Relevant academic research and scientific papers
Addition of silver electrophiles to an electron-rich rhodium-rhodium bond. Synthesis and X-ray crystal structure of the [Rh2(η-C5H5) 2(μ-CO)(μ-Ph2PCH2PPh 2)(μ-AgOPF2O)], a triangular rhodium-silver cluster with the difluorophosphate ion coordinated to the silver atom
Bruno, Giuseppe,Lo Schiavo, Sandra,Piraino, Pasquale,Faraone, Felice
, p. 1098 - 1100 (2008/10/08)
[Rh2(η-C5H5) 2(μ-CO)(μ-dppm)] (1) [dppm = bis(diphenylphosphino)methane] reacts with AgX (X = BF4-, PF6-, ClO4-) to give [Rh2Ag(η-C5H5) 2(μ-CO)(μ-dppm)]X (2a-c); in solution the complexes 2a-c are very unstable. During these experiments using, by accident, an old and humid sample of AgPF6, the neutral compound [Rh2(η-C5H5)2(μ-dppm) (μ-AgOPF2O)] (3) was obtained; the same compound is also obtained by reacting 1 with silver difluorophosphate. The compound 3 has been spectroscopically and structurally characterized. It crystallizes in the space group Pnma; the cell dimensions are a = 14.471 (1) A?, b = 18.042 (2) A?, c = 12.772 (1) A?, V = 3334.5 A?3, and Z = 4. The structure has been refined to R = 0.051 and Rw = 0.048 for the 1281 reflections with I ≥ 3σ(I). In the triangular Rh2Ag framework the two Rh-Ag distances [2.689 (2) A?] are equivalent, and the Rh-Rh bond [2.750 (3) A?] is lengthened by 0.067 A? on silver adduct formation. The rhodium atoms are bridged by the CO and the dppm ligands; each rhodium atoms is further coordinated to the η5-cyclopentadienyl ligand. The structural features of the bridging dppm and CO groups remain essentially the same as in 1. The cyclopentadienyl ligands are in cis position. The difluorophosphate ion is O bonded to silver atom [Ag-O(S) = 2.12 (2) A?] and shows the phosphorus atom tetrahedrally coordinated.
