Nickel–iridium carbonyl clusters. Synthesis and solid-state structure of the trianion [Ir3Ni6(µ-CO)6(µ3-CO)2(CO)9]3–. The first example of a mixed iridium–nickel carbonyl cluster

Abstract

The dark brown [Ir₃Ni₆(µ-CO)₆(µ₃-CO)₂(CO)₉]^3– trianion has been obtained by redox condensation between [Ni(CO)₄] and [Ir(CO)₄]^–. This new mixed-metal cluster is rapidly degraded, at room temperature and atmospheric pressure, by carbon monoxide to form the [Ni(CO)₄] and [Ir(CO)₄]^– parent mononuclear compounds. The salt [NMe₂(CH₂Ph)₂]₃[Ir₃Ni₆(CO)₁₇] crystallizes in the monoclinic space group P2₁/c(no. 14) with a= 24.295(4), b= 12.765(3), c= 23.898(5), β= 113.68(1)°, and Z= 4. The structure was solved by conventional Patterson and Fourier methods and refined by full-matrix least squares to a final R value of 0.032 for 6 169 independent reflections having I > 3σ(I). The metal framework consists of a face-sharing bioctahedron, with the three iridium atoms located in the inner triangle.