Organosilicon-Based Multifunctional β-Diketones and their Rhodium and Iridium Complexes

Six new organosilicon-based bis-, tris-, and tetrakis(β-diketones) and their RhI(COD) and IrI(COD) (COD = 1,5-cyclooctadiene) complexes have been prepared and characterized. The β-diketones, (CH3)4−nSi(4-C6H4CH(COR)2)n (n = 2, 3, 4; R = Me, Et), were prepared from the corresponding aldehydes (CH3)4−nSi(4-C6H4CHO)n by reaction with trimethyl phosphite-α-diketone adducts. Reaction with [M(COD)(μ-Cl)]2 (M = Rh and Ir) produces the Rh and Ir complexes, three of which have been characterized by X-ray analysis. The β-diketone moieties are ca. 13.3 Å apart, which leads to intramolecular M···M distances in the complexes averaging ca. 15.6 Å. The present organosilicon-based route is expected to be useful for the construction of a variety of polytopic molecules containing either β-diketone or other functional groups and polygonal or polyhedral metal complexes based on them.