title: Heterobimetallic complexes of rhodium dibenzotetramethylaza[14]annulene [(tmtaa)Rh-M]: formation, structures, and bond dissociation energetics.
abstract: 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(μ-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.
authors.affiliation: Department of Chemistry, Temple University , 1901 North 13th Street, Philadelphia, Pennsylvania 19122, United States.
authors.forename: Gregory H
authors.initials: GH
authors.lastname: Imler
authors.forename: Garvin M
authors.initials: GM
authors.lastname: Peters
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zdilla
authors.forename: Bradford B
authors.initials: BB
authors.lastname: Wayland