A mass spectrometry and surface enhanced Raman spectroscopy study of the interaction between linear carbon chains and noble metals

Linear carbon chains (LCCs) contain sp hybridization either as alternating triple and single bonds (polyynes) or with consecutive double bonds (cumulenes). They are detected here in solution by a combined mass spectrometry (MS) and surface enhanced Raman scattering approach, and new insight into the carbon structures, formed after performing pulsed laser ablation of a polycrystalline graphite rod in water stabilized by the presence of metals is given. The possibility to establish a LCC–metal bond is also investigated by carrying out atmospheric pressure matrix assisted laser desorption ionization MS experiments on copper and silver polyynides. It was found that while the interaction of metal colloids with LCCs results mainly in a weak bond, polyynides appear as true organometallic compounds in which the metal is covalently bonded to the LCCs.