FOURIER-TRANSFORM MASS-SPECTROMETRIC STUDIES OF ISOVALENT RARE-EARTH IONS SC+, Y+ AND LU+ WITH METHANOL - FORMATION OF DIMETHOXIDE METAL SPECIES M(OCH3)2+

The primary and subsequent gas-phase reactions between methanol and the isovalent rare earth metal ions Sc+, Y+ and Lu+ have been investigated using a Fourier transform ion cyclotron resonance mass spectrometer. The three metal ions react exothermically with methanol. Among the primary reaction products obtained, only two are common to the three metals, the hydroxide-metal ions MOH+, and the methoxide-metal ions MOCH3+. For Sc+ and Y+, as primary products the metal oxide ions MO+, and the metal-formaldehyde complexes M(OCH2)+, are also observed, as well as the formation of the metal-dihydride ion MH2+ (only for Y+). All the primary ions undergo subsequent reactions with methanol, and the final product is always the M(OCH3)2(CH3OH)n+ species (n = 0-3). The results are analysed to yield the lower and/or upper limits for bond energies: D-degrees-(M+-OH) and D-degrees-(HOM+-OH) > 92 kcal mol-1, D(HOM+-OCH3) and D-degrees-(M+-OCH3) > 105 kcal mol-1 for M = Y and Lu, D-degrees-(HOSc+-OCH3) and D-degrees-(Sc+-OCH3) > 119 kcal mol-1, D-degrees-(Sc-OH) < 168 kcal mol-1, D-degrees-(Y-OH) < 175 kcal mol-1, and D-degrees-(Lu-OH) < 194 kcal mol-1.