97689-99-1Relevant academic research and scientific papers
Chemical and electrochemical oxidation of the phosphoniodichalcogenoformate complexes (triphos)RhCl(X2CPEt3) (triphos = MeC(CH2PPh2)3; X = S, Se). Synthesis of metal dichalcogenocarbonates from O2 and phosphonium-betaine-like complexes. X-ray structure of [(triphos)Rh(S2CH(PEt3))](BPh4)2
Bianchini, Claudio,Meli, Andrea,Dapporto, Paolo,Tofanari, Anna,Zanello, Piero
, p. 3677 - 3682 (2008/10/08)
The phosphoniodichalcogenoformate complexes (triphos)RhCl(η1-X2CPEt3) (X = S, 1; Se, 2) are chemically or electrochemically oxidized to [(triphos)RhCl(η2-X2CPEt3)]2+ (triphos = MeC(CH2PPh2)3). These dications, which may add as many as two electrons to regenerate the starting compounds, react with EtOH, yielding octahedral phosphonium-betaine complexes of the formula [(triphos)RhCl(X2CH(PEt3))]+. The five-coordinate derivatives [(triphos)Rh(X2CH(PEt3))]2+ are obtained via chloride ligand elimination. Alternatively, the latter compounds can be prepared by the one-step reaction of 1 or 2 with HOSO2CF3 in the presence of NaBPh4. Methylation of 1 by MeOSO2CF3 gives the analogous complex containing the novel S2CMe(PEt3)- ligand. The structure of [(triphos)Rh(S2CH(PEt3))](BPh4)2 has been determined by X-ray methods. Crystal data: monoclinic, space group P21/n, with a = 18.433 (6) A?, b = 27.384 (8) A?, c = 16.229 (6) A?, β = 92.25 (4)°, and Z = 4. The structure was refined to an R factor of 0.075 (Rw = 0.075) for 4906 unique reflections. The rhodium atom is coordinated by the three phosphorus atoms of triphos and by the two sulfur atoms of the S2CH(PEt3)- ligand in a distorted-square-pyramidal environment. The neutral or cationic dichalcogenocarbonate complexes (triphos)RhCl(S2CO) and [(triphos)Rh(X2CO)]+ are obtained by reaction of O2 with solutions of [(triphos)RhCl(S2CH(PEt3))]+ and [(triphos)Rh(X2CY(PEt3))]2+ (Y = H, Me), respectively. Pathways to the formation of the products are proposed and discussed.
