Highly fluorous complexes of ruthenium and osmium and their solubility in supercritical carbon dioxide.

A series of ruthenium and osmium complexes containing highly fluorous diphosphine ligands (F)P(wedge)P(F) = (F(13)C(6)C(6)H(4)-p)(2)P(CH(2))(2)P(p-C(6)H(4)C(6)F(13))(2) (dfppe) and (F(13)C(6)C(6)H(4)-p)(2)P(CH(2))(3)P(p-C(6)H(4)C(6)F(13))(2) (dfppp) has been prepared. The fluorous diphosphine ligands incorporate four C(6)F(13) "fluoro-ponytails", and these have been effective in solubilizing the complexes in supercritical carbon dioxide (scCO(2)). Precise solubility measurements in scCO(2) were performed for some of the complexes. The new complexes [MX(2)((F)P(wedge)P(F))(2)] and [MX((F)P(wedge)P(F))(eta-C(5)H(5))], M = Ru, Os, X = Cl, Br, have been characterized by a number of spectroscopic techniques and their electrochemical properties measured, three of the ruthenium complexes also being characterized by single-crystal X-ray studies. The noncovalent interactions observed in the X-ray structures have been analyzed by the Hirshfeld surface approach, putting them on a more solid footing. The fluorinated complexes show significantly different solvation properties from those of the analogous unfluorinated compounds, particularly with respect to their behavior in common organic solvents and their good scCO(2) solubility.