Fluorocarbon complexes of the transition metals. Part III. Chemistry of tertiary arsine derivatives of tetrakis(trifluoromethyl)rhodacyclo-pentadiene

Abstract

The five-co-ordinate rhodacyclopentadiene complexes [RhClL₂C₄(CF₃)₄][L = AsMe₃, AsMe₂Ph, or AsMe₂-(p-MeOC₆H₄)] react readily with a variety of neutral ligands to give six-co-ordinate species [RhClL′L₂C₄(CF₃)₄][L′= py, NH₃, MeCN, PHPh₂, P(OMe)₃, AsMe₃, or P(OCH₂)₃CC₂H₅]. The corresponding six-co-ordinate carbonyl complexes [Rh(CO)ClL₂C₄(CF₃)₄] react with silver salts to produce [Rh(CO)XL₂C₄(CF₃)₄](X = CF₃CO₂^–or ClO₄^–) or [RhXL₂C₄(CF₃)₄](X = CH₃CO₂^– or p-MeC₆H₄SO₃^–). These same complexes also react with [Tl(dike)] to give [Rh(dike)L₂C₄(CF₃)₄][dike = acetylacetonate(acac) or hexafluoroacetylacetonate(hfac)]. Treatment of [RhCl(CO)L₂C₄(CF₃)₄] with AgClO₄ followed by a neutral ligand gives the complexes [RhL_2′L₂C₄-(CF₃)₄][ClO₄][L′= MeCN or P(OMe)₃; L₂′= diars]. In the complexes [RhClL′L₂C₄(CF₃)₄](L′= py, MeCN, AsMe₃, or H₂O), L′ undergoes exchange in solution at 30 °C. Static six-co-ordinate structures for these complexes can be achieved at low temperatures. The ¹H and ¹⁹F spectra of these complexes over a range of temperatures were measured and the results are discussed, I.r. and ¹H and ¹⁹F n.m.r. spectra of the remaining complexes are also discussed.