Rhodium(I) Ferrocenylcarbene Complexes: Synthesis, Structural Determination, Electrochemistry, and Application as Hydroformylation Catalyst Precursors.

New examples of the rare class of rhodium(I) ferrocenyl Fischer carbene complexes 1-8, [Rh(LL)Cl{C(XR)Fc}] [LL = cod, (CO)2, (CO, PR3) (R = Ph, Cy or OPh), and (CO, AsPh3); XR = OEt or NHnPr] were prepared, and the electronic effects of coligands and alkoxy vs aminocarbene substituents were investigated by spectroscopic and electrochemical methods. The molecular structures of complexes 1, 2, and 4-6 were confirmed by single-crystal X-ray diffraction. The use of the complexes 1-8 as homogeneous catalysts for the hydroformylation of 1-octene was demonstrated, and the influence of the carbene substituents and coligands on the activity and regioselectivity of the catalysts evaluated. Finally, the stability of the Rh-Ccarbene bond of complex 1 under hydroformylation conditions was confirmed with 13C NMR experiments. [ABSTRACT FROM AUTHOR]