Infrared spectra and density functional theory calculations for Mn -(CH4)n (n=1-6) clusters

Abstract

Infrared spectra are measured for the mass-selected Mn(CH4)n+ (n=1-6) clusters in the C-H stretch region (2700-3100cm-1) by monitoring photofragment ions. Accompanying density functional theory calculations are performed for possible structural isomers, including the Mn+-(CH4)n ion-molecule complexes in which the ligands are attached to the Mn+ ion in an η3 configuration, and the inserted H-Mn-CH3+-(CH4)n-1 complexes. The experimental infrared spectra for all species are dominated by a single band, appearing at 2836cm-1 for n=1 and progressively shifting to 2880cm-1 for n=6. The observed infrared spectra match predicted spectra for Mn+-(CH4)n ion-molecule complexes containing Mn+ in its 7S (..