Infrared Photodissociation Spectroscopy of D₂-tagged Cation Prepared in a Cryogenic Ion Trap

We present an experimental setup for investigating infrared photodissociation spectroscopy (IRPD) for cold messenger-tagged ions produced in a cryogenic Paul trap using a pulsed cold buffer gas. Cluster ions are generated via laser ablation and supersonic expansion, and subsequently trapped in a cryogenic Paul trap. An intense pulse of cold D2 gas is applied to thermalize the ions and form the D2-tagged complexes via three-body collisions. The messenger-tagged ion of interested is mass-selected in a time-of-flight (TOF) mass spectrometer combined with a reflectron to conduct IRPD spectroscopy. IRPD spectrum of D₂-tagged Au⁺(H₂O)₅ was measured and compared with that of argon-tagged complex. The results demonstrates the significant influence of messenger molecules on the IRPD spectral features.