Successive reactions of iron carbonyl cations with methanol
Heninger, M × Pernot, P Mestdagh, H Boissel, P Lemaire, José Marx, R Mauclaire, G #
Elsevier science bv
International journal of mass spectrometry vol:199 issue:1-3 pages:267-285
The reactivity of Fe(CO)(n)(+) cations with methanol has been investigated using a triple-cell Fourier transform ion cyclotron resonance apparatus. Successive substitutions of the CO ligands by methanol occur rapidly with similar rates. For it = 3-5 the last CO ligand is not replaced, and the terminal substitution products are FeCO(CH3OH)(n-1)(+). A second reaction pathway is observed for n = 3-5, in which two CO ligands are replaced by one methanol molecule. This pathway occurs even if the Fe(CO)(n)(+) ions have been radiatively relaxed before reaction, providing information on the bond energies in the product ions. Strong internal energy effects are observed on the reaction rates and branching ratios for further substitution of the intermediate products. The substitution product Fe(CH3OH)(+) from FeCO+ reacts further, with C-O bond cleavage followed by substitution. The resulting Fe[C-2, H-7, O-2](+) ion undergoes either isomerization or collisional deactivation, then slow association with methanol. The reaction of Fe+, due to excited states only, begins with formation of FeOH+ and involves the same final steps as in the preceding case. (Int J Mass Spectrom 199 (2000) 267-285) (C) 2000 Elsevier Science B.V.