Hydrogen-Assisted C-C Coupling on Reaction of CuC₃H^- Cluster Anion with CO^†

A fundamental study on C-C coupling, that is the crucial step in the Fischer-Tropsch synthesis (FTS) process to obtain multi-carbon products, is of great importance to tailor catalysts and then guide a more promising pathway. It has been demonstrated that the coupling of CO with the metal carbide can represent the early stage in the FTS process, while the related mechanism is elusive. Herein, the reactions of the CuC _3 H ^- and CuC _3 ^- cluster anions with CO have been studied by using mass spectrometry and theoretical calculations. The experimental results showed that the coupling of CO with the C _3 H ^- moiety of CuC _3 H ^- can generate the exclusive ion product COC _3 H ^- . The reactivity and selectivity of this reaction of CuC _3 H ^- with CO are greatly higher than that of the reaction of CuC _3 ^- with CO, and this H-assisted C-C coupling process was rationalized by theoretical calculations.