Pseudocarbynes: Linear Carbon Chains Stabilized by Metal Clusters

Pseudocarbynes, defined as linear carbon chains stabilized by noncovalent bonding to a metal cluster, were synthesized via laser ablation of a liquid/metal interface, in this case, gold (Au) in ethanol. We present UV-vis, Raman, and IR spectra that collectively demonstrate the formation of Au-pseudocarbynes. The Au-pseudocarbynes presented here likely consist of polyynes containing fewer than 16 carbon atoms associated with subnanometer Au clusters. Their characteristic spectral signatures are supported by density functional theory calculations that highlight the interaction between the Au clusters and the pi network of -C C- chains. This class of molecules represents a synergy between sp-hybridized carbon chains and small metal clusters that stabilize one another.