Dioxygen Complexes of 3d Transition-Metal Atoms: Formation Reactions in the Gas Phase

Article abstract of DOI:10.1021/j100156a009

Reactions of ground-state 3d transition-metal atoms including Ti, Mn, Co, Ni, and Cu with molecular oxygen in Ar buffer gas have been investigated in the pressure range 5-700 Torr at 296 K.Attention has been given to termolecular association reactions in which mono(dioxygen) complexes are formed.A pulsed laser photolysis-laser fluorescence technique is used where metal atoms are produced by visible multiphoton dissociation of a volatile organometallic precursor in a static pressure reaction cell, and reactions of metal atoms are monitored by resonance fluorescence excitation at variable time delay following the photolysis pulse.The pres ent study completes a survey of the reactions of 3d transition-metal atoms with O2 under room temperature conditions, from which it emerges that reactivity with respect to complex formation is correlated with a dⁿs¹ valence electron configuration of the metal atom.Simplified RRKM calculations have been used to interpret termolecular rate constants for the association reactions in terms of a trend in the binding energies of the dioxygen complexes.