Infrared studies of the interaction of methanol with Cun, Agn, and Aun

Methanol (Me) adsorbs intact on copper, silver, and gold clusters at 70 K to form thp complexes CunMem, AgnMem, and AunMem, respectively. The infrared photodissociation spectra of the deuterium-substituted complexes M-n(CD3OH)(m) and M-n(CD3OD)(m) (M-n = Cu3-11, Ag3-22, and Au3-13) have been recorded in the 9-11 mu m region. The methanol C-O stretching band frequency is invariant with cluster size and depends only slightly on the metal of which the underlying cluster is composed, indicating that local interactions are responsible for the shift from the gas-phase value and that these interactions are similar for methanol adsorbed on clusters of all three metals. Progressive blue shifts of the depletion bands of AgnMem and AunMem with increasing m indicate a strong interaction among methanol ligands in these species.