MALDI-TOF Mass Spectrometry of Nanosized MoO 2 . Structure and Relative Stability of Isomers of Lower Molybdenum Oxide Cations

MALDI-TOF was used to study molybdenum dioxide (MoO2) containing a nanosized fraction. The composition of cationic clusters of nonstoichiometric lower molybdenum oxides in the gas phase was determined, and the thermodynamic stabilities and configurations of isomers were calculated for selected symmetric molecular structures and for cations MoSO 8 + and Mo5O 9 + . Molecular orbital analysis was performed for two trigonal-bipyramidal clusters Mo5O8 and Mo5O9. Changes in molybdenum–molybdenum interatomic distances in going from MoO 8 + and Mo5O 9 + cations to neutral clusters are discussed.