Fragmentation of alkoxo(catecholato)vanadium(V) complexes [(C6H4O2)V(OR1)(OR2)]+ in the gas phase

Electrospray ionization (ESI) mass spectrometry is used to investigate the gas-phase dissociation behavior of vanadium(v) complexes [(C6H4O2)V(OR1)(OR2)](+) containing two identical or different alkoxy groups (R-1, R-2 = CH3, C2H5, n-C3H7, i-C3H7 and t-C4H9) and a catecholato ligand (C6H4O2). The fragmentation reactions of the complexes are studied by collision-induced dissociation (CID) and labeling experiments. For [(C6H4O2)V(OR1)(OR2)](+) cations with alkoxo groups larger than methyl, a trend for preferential evaporation of hydrocarbon fragments is observed, followed by expulsion of neutral alcohols. Further, the CID spectra of all complexes show a signal which can be assigned to the complex [(C6H4O2)VO](+). (c) Wiley-VCH Verlag GmbH & Co.