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Infrared multiple photon dissociation spectroscopy (IR-MPD) has been employed to determine the nature of CO 2 binding to size-selected platinum cluster anions, Pt n - (n=4-7). Interpreted in conjunction with density functional theory simulations, the results illustrate that the degree of CO 2 activation can be controlled by the size of the metal cluster, with dissociative activation observed on all clusters n≥5. Of potential practical significance, in terms of the use of CO 2 as a useful C1 feedstock, CO 2 is observed molecularly-bound, but highly activated, on the Pt 4 - cluster. It is trapped behind a barrier on the reactive potential energy surface which prevents dissociation., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

We report the observation of chemical reactions in gas-phase Rh(n)(N2O)m(+) complexes driven by absorption of blackbody radiation. The experiments are performed under collision-free conditions in a Fourier transform ion cyclotron resonance mass spectrometer. Mid-infrared absorption by the molecularly adsorbed N2O moieties promotes a small fraction of the cluster distribution sufficiently to drive the N2O decomposition reaction, leading to the production of cluster oxides and the release of molecular nitrogen. N2O decomposition competes with molecular desorption and the branching ratios for the two processes show marked size effects, reflecting variations in the relative barriers. The rate of decay is shown to scale approximately linearly with the number of infrared chromophores. The experimental findings are interpreted in terms of calculated infrared absorption rates assuming a sudden-death limit., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)