Reactions of Nb n + (n = 1−15) with Propene and 1-Butene:  Product Distribution as a Function of Cluster Size

The reactions of niobium cluster cations (Nb n +, n = 1−15) with propene and 1-butene are studied using Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Reaction product distributions as a function of cluster size are presented. The branching ratios of paths corresponding to single and multiple dehydrogenations in the primary reactions are reported and interpreted qualitatively in terms of the bonding between the ligands and the metal cluster centers. The bonding in products of higher order reactions are addressed by discussing the trends in the reaction saturation limits and the presence of C−C bond cleavage products in some reactions.