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 [Ru-8(H-2)(1)(N-2)(4)](+) and [Ru-8(N-2)(4)(H-2)(1)](+) species differing in the adsorption sequence of H-2 and N-2, which we record via application of tandem cryo ion trapping. We observe strong evidence for dissociative H-2 adsorption, and the spectra reveal differences in the Ru-H stretching region, which we assign to distal and proximal hydrogen atom locations on the Ru-8(+) cluster, their migration likely hindered by preloaded nitrogen molecules and unaffected by subsequent N-2 adsorption.