Phenyl–gold complexes of Ru6 and Ru5 carbonyl clusters

•Oxidative-addition of the Au–C bond to a ruthenium carbonyl cluster complex.•A σ–π-coordinated phenyl ligand that dynamically interchanges its coordination between the two sides of the ring.•CO insertion into a Ru–phenyl bond to form a bridging benzoyl ligand in an opened Ru5 cluster complex.

The reactions of Ru6(C)(CO)17, 1 and Ru5(C)(CO)15, 2 with (NHC)AuPh, NHC = 1,3-bis(2,6-diisopropylphenyl-imidazol-2-ylidene) have yielded the π-arene Ru6 complex Ru6C(CO)14[η6-PhAu(NHC)], 3 and two Ru5 complexes, Ru5C(CO)14(Ph)[μ-Au(NHC)], 4 and Ru5C(CO)13(μ–η2-Ph)[μ-Au(NHC)], 5, respectively. Compounds 4 and 5 were formed by oxidative-addition of the Au–C bond at the ruthenium atoms. Compound 5 contains a μ–η2–σ–π-coordinated phenyl ligand that is dynamically interchanging its coordination between the two sides of the ring on the 1H NMR time scale at room temperature. Compounds 4 and 5 both react with CO to yield the CO insertion product Ru5C(CO)14(μ–η2-OCPh)[μ-Au(NHC)], 6 that contains a bridging benzoyl ligand in an opened Ru5 cluster complex. The syntheses and X-ray crystal structures of these new complexes are reported.

Graphical abstractThe new gold–ruthenium complexes Ru6C(CO)14[η6-PhAu(NHC)], 3 and Ru5C(CO)14(Ph)[μ-Au(NHC)], 4 and Ru5C(CO)13(μ–η2-Ph)[μ-Au(NHC)], 5, have been synthesized and structurally characterized. Compounds 4 and 5 react with CO to yield the benzoyl bridged complex Ru5C(CO)14(μ–η2-OCPh)[μ-Au(NHC)], 6.Figure optionsDownload full-size imageDownload as PowerPoint slide