Cryo IR Spectroscopy of N 2 and H 2 on Ru 8 + : The Effect of N 2 on the H-Migration.

We present the cryo IR-PD spectra of the coadsorbed [Ru8 (H2 )1 (N2 )4 ]+ and [Ru8 (N2 )4 (H2 )1 ]+ species differing in the adsorption sequence of H2 and N2 , which we record via application of tandem cryo ion trapping. We observe strong evidence for dissociative H2 adsorption, and the spectra reveal differences in the Ru-H stretching region, which we assign to distal and proximal hydrogen atom locations on the Ru8 + cluster, their migration likely hindered by preloaded nitrogen molecules and unaffected by subsequent N2 adsorption.