Adsorption of C2H radical on cobalt clusters: anion photoelectron spectroscopy and density functional calculations

We investigated the adsorption of C(2)H radical on small cobalt clusters by mass spectrometry and by measuring the photoelectron spectra of Co(n)C(2)H(-) (n = 1-5) cluster anions. The most stable structures of Co(n)C(2)H(-) (n = 1-5) and their neutrals were determined by comparing the experimental results with theoretical calculations. Our studies show that C(2)H radical still maintains its integrity as a structural unit in Co(n)C(2)H(-) clusters, rather than being divided by Co(n) clusters. The most stable isomers of Co(1-2)C(2)H(-) clusters are linear with the C(2)H interacting with only one Co atom, while those of Co(3-5)C(2)H(-) cluster anions are quasi-planar structures with the carbon-carbon bonds bending slightly toward the Co(3-5) clusters. The carbon-carbon bond of C(2)H is lengthened more in Co(3-5)C(2)H(-) clusters than in Co(1-2)C(2)H(-).