The effect of D-2/H-2 substitution on the Nb-n(+)+H-2 reaction

The effect of D-2/H-2 substitution on the reactions of niobium cluster cati ons Nb-n(+) (n = 5 -9) with hydrogen was studied using a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer combined with a laser-ab lation/supersonic-jet external ion source. For most cluster sizes, it has b een found that the reactions of the Nb-n(+) clusters with H2D2 mixture yiel d considerable amounts of NbnHD+ even at small conversion of Nb-n(+). These results suggest a mechanism which involves the dissociative chemisorption of H-2 on the niobium cluster, followed by the competing stabilization and back dissociation of the energized adduct.