Inorganic Chemistry, Vol.54, No.1, 273-279, 2015
Heterobimetallic Complexes of Rhodium Dibenzotetramethylaza[14]annulene [(tmtaa)Rh-M]: Formation, Structures, and Bond Dissociation Energetics
A rhodium(II) dibenzotetramethylaza[14]annulene dimer ([(tmtaa)Rh](2)) undergoes metathesis reactions with [CpCr(CO)(3)](2), [CpMo(CO)(3)](2), [CpFe(CO)(2)](2), [Co(CO)(4)](2), and [Mn(CO)(5)](2) to form (tmtaa)Rh-M complexes (M = CrCp(CO)(3), MoCp(CO)(3), FeCp(CO)(2), Co(CO)(4), or Mn(CO)(5)). Molecular structures were determined for (tmtaa)Rh-FeCp(CO)(2), (tmtaa)Rh-Co(mu-CO)(CO)(3), and (tmtaa)Rh-Mn(CO)(5) by X-ray diffraction. Equilibrium constants measured for the metathesis reactions permit the estimation of several (tmtaa)Rh-M bond dissociation enthalpies (Rh-Cr = 19 kcal mol(-1), Rh-Mo = 25 kcal mol(-1), and Rh-Fe = 27 kcal mol(-1)). Reactivities of the bimetallic complexes with synthesis gas to form (tmtaa)Rh-C(O)H and M-H are surveyed.