Infrared Signature of Structural Isomers of Gas-Phase M(NO) (M = Cu, Ag, Au) Ion-Molecule Complexes.

Gas-phase metal ion-ligand complexes offer model environments to study molecular interactions that are key to many catalytic processes. Here, we present a combined experimental and computational study of M(NO) [M = Cu, Ag, Au; n = 2-7] complexes. The spectra provide clear evidence for both nitrogen- and oxygen-bound ligands giving rise to a wide range of structural isomers for each complex studied. The evolution of the complex structures observed as well as spectral trends for each metal center are interpreted in terms of a molecular orbital binding picture and resulting calculated ligand binding energies. Given the environmental importance of nitrogen oxides, these results have implications for metal-catalyzed removal of nitrous oxide and, particularly, the prospect of initiating infrared-driven isomer-selective chemistry in size-selected complexes.