Molecular mass determination of saturated hydrocarbons: reactivity of η⁵-cyclopentadienylcobalt ion (CpCo^·+) and linear alkanes up to C-30

Abstract

The present study demonstrates the feasibility of the 5 -cyclopentadienylcobalt ion (CpCo ⅐ϩ ) as a suitable cationization reagent for saturated hydrocarbon analysis by mass spectrometry. Ion/molecule reactions of CpCo ⅐ϩ and three medium chain-length n-alkanes were examined using Fourier-transform ion cyclotron resonance mass spectrometry. Second-order rate constants and reaction efficiencies were determined for the reactions studied. Loss of two hydrogen molecules from the CpCo-alkane ion complex was found to dominate all reactions (Ն80%). Furthermore, this dehydrogenation reaction efficiency increases with increasing chain length. These preliminary results suggest that the CpCo ⅐ϩ ion may be a promising cationization reagent of longer chain saturated hydrocarbons and polyolefins.