Infrared Spectra and Structures of Silver–PAH Cation Complexes

Hybrids of metal atoms and polycyclic aromatic hydrocarbons (PAHs) are promising building blocks for new materials with tailored opto-electronic properties. We report the first experimental mid-infrared (550–1650 cm^–1) spectra of [Ag–PAH]⁺ complexes measured in the linear absorption regime via messenger tagging of size-selected cryogenically cooled complexes. Infrared photodissociation (IRPD) spectra of [Ag–PAH]⁺·Ne complexes (PAH = naphthalene and azulene) are assigned on the basis of a comparison to simulated vibrational spectra from density functional calculations. The analysis of the IRPD spectra, which resolve IR bands as weak as a few km/mol, allows us to identify the Ag⁺ binding site and to gain valuable insight into the effects of Ag⁺ complexation on the geometry and charge distribution of the PAH