The gas phase reactivity of small cationic cobalt clusters, Co-n(+) (n = 1-
12), towards methanol has been investigated using Fourier transform ion cyc
lotron resonance mass spectrometry. Sequential addition of methanol molecul
es to the clusters was observed to be the dominating process, with the exce
ption of Co-4(+) and Co-5(+) for which dehydrogenation of methanol was the
dominating initial reaction step. Isotopic labelling studies with CD3OH sho
wed that the dehydrogenation is a1,1-elimination reaction involving the met
hyl group. Loss of a cobalt atom upon methanol addition was also observed t
o be a facile process, being most pronounced for Co-2(+) Co-3(+) and Co-6(). (C) 2000 Elsevier Science B.V. All rights reserved.