Synthesis, characterization of new RhCo mixed-metal clusters and reactions of clusters containing [Rh2Co2C2] core with 1-alkynes and/or carbon monoxide

Six new cluster derivatives [Rh2Co2(CO)6(μ-CO)4(μ4,η2-HCCR)] (R=FeCp21, CH2OH 2, (CH3O)C10H6CH(CH3)COOCH2CCH 3) and [RhCo3(CO)6(μ-CO)4(μ4,η2-HCCR)] (R=FeCp24, CH2OH 5, (CH3O)C10H6CH(CH3)COOCH2CCH 6) were obtained by the reactions of [Rh2Co2(CO)12] and [RhCo3(CO)12] with substituted 1-alkyne ligands HCCR [R=FeCp27, CH2OH 8, (CH3O)C10H6CH(CH3) COOCH2CCH 9] in n-hexane at room temperature, respectively. Alkynes insert into the CoCo bond of the tetranuclear clusters to give butterfly clusters. [Rh2Co2(CO)6(μ-CO)4(μ4,η2-HCCFeCp2)] (1) was characterized by a single-crystal X-ray diffraction analysis. Reactions of 1, 2 with 7, 8 and ambient pressure of carbon monoxide at 25 °C gave two known cluster complexes [Co2(CO)6(μ2, η2-HCCR)] (R=FeCp210, CH2OH 11), respectively. All clusters were characterized by element analysis, IR and 1H-NMR spectroscopy.