GAS-PHASE REACTIVITY OF RARE-EARTH CATIONS WITH PHENOL - COMPETITIVE ACTIVATION OF C-O, O-H, AND C-H BONDS

The gas-phase reactions of Sc+, Y+, and Ln(+) (Ln = La-Lu, except Pm) ions with phenol were studied by Fourier transform ion cyclotron reson ance mass spectrometry. All the ions except Yb+ were observed to react with the organic substrate, activating O-H, C-O, and/or C-H bonds, wi th formation of MO+, MOH+, and/or MOC6H4+ ions as primary products. Th e product distributions and the reaction efficiencies obtained showed the existence of important differences in the relative reactivity of t he rare earth metal cations, which are discussed in terms of factors l ike the electron configurations of the metal ions, their oxophilicity, and the second ionization energies of the metals. The primary product ions participated in subsequent reactions, yielding species such as M (OH)(OC6H5)(+), which lead mainly to M(OC6H5)(2)(HOC6H5)(n)(+) ions, w here n = 0-2. Formation of M(OC6H(5))(HOC6H5)(n)(+) species was also o bserved in the case of the metals that have high stabilities of the fo rmal oxidation state 2+, Sm and Eu. (C) 1998 American Society for Mass Spectrometry.