CARBON-CARBON BOND FORMATION PROMOTED BY BARE LANTHANIDE CATIONS - THE REACTIONS OF CE+ AND LA+ WITH PROPENE IN THE GAS-PHASE

The cationic butadiene and benzene complexes CeC4H6+ and CeC6H6+ are the main products in the reaction of thermalized Ce+ ions with propene in the gas phase, as shown by FT MS, Following the formation of the primary products, i.e. CeCH2+ and CeC3H4+, selective C-C coupling processes at the lanthanide cation occur as secondary reactions with high efficiency. Ligand-exchange reactions and comparative collision-induced dissociation experiments are applied to probe the structures of the final reaction products of this first example of Ce+ gas-phase chemistry. The reaction of Ce+ with cyclopropane yields a product distribution very similar to the propene reaction; however, it reacts significantly slower. Furthermore, La+ reacts in nearly the same manner with propene as Ce+ which indicates that the single f electron in the latter ion is chemically inert.