Spectroscopic studies on C2 hydrocarbon fragments. Part 2. Vibrational group frequencies and carbon-13 nuclear magnetic resonance chemical shifts of cluster-bound C2Hn(n= 1–4) fragments
Vibrational and 13C n.m.r. spectra have been recorded on [Os3(CO)11(η2-C2H4)], [M3(CO)9(µ-H)3(µ3-CMe)](M = Ru or Os), [Os3(CO)10(µ3-η2-HCCH)], [Os3(CO)9(µ-H)(µ3-η2-CCH)], [Ru2(CO)3(η5C5H5)2(µ-CHMe)], [Ru2(CO)3(η5-C5H5)2(µ-CMe)]BF4, and [Os3(CO)9(µ-H)(µ-SPrn)L](L = CO, C2H4, or C2H2). In conjunction with published data, 13C n.m.r. shift ranges of C1, and C2 cluster-bound hydrocarbon fragments have been identified. Vibrational group frequencies of the C2Hn(n= 1–4) moieties have also been proposed. On this basis, acetylene is suggested to rearrange to a µ3-η2-vinylidene on Ni(111) and Fe(110) surfaces.