Structural rearrangement in gas phase niobium carbide clusters, Nb C3 and Nb C6

Weak Interactions Initiate C-H and C-C Bond Dissociation of Ethane on Nbn + Clusters

The conversion of ethane into value-added chemicals under ambient conditions has attracted much attention but the mechanisms remain not fully understood. Here we report a study on the reaction of ethane with thermalized Nb_n ⁺ clusters based on a multiple-ion laminar flow tube reactor combined with a triple quadrupole mass spectrometer (MIFT-TQMS). It is found that ethane reacts with Nb_n ⁺ clusters to form both products of dehydrogenation and methane-removal (odd-carbon products). Combined with density functional theory (DFT) calculations, we studied the reaction mechanisms of the C-C bond activation and C-H bond cleavage on the Nb_n ⁺ clusters. It is unveiled that hydrogen atom transfer (HAT) initiates the reaction process, giving rise to the formation of Nb-C bonds and an elongated C-C distance in the HNb_n ⁺ CH₂ CH₃ motif. Subsequent reactions allow for C-C bond activation and a competitive HAT process which is associated with CH₄ removal or H₂ release, resulting in the production of the observed carbides.

The reactivity of Nbn+ clusters with acetylene and ethylene to produce a cubic aromatic metal carbide Nb4C4+

The reactions of niobium cationic clusters with acetylene and ethylene under sufficient gas collision conditions give rise to dominant dehydrogenation and produce a main metal carbide Nb4C4+ which is associated with cubic aromaticity.