Cryo-cooled Ion Spectroscopy

Technical Details

Studies of the infrared and ultraviolet spectroscopy of large molecular ions and complexes are carried out in a versatile, multi-stage mass spectrometer that incorporates a cryogenically cooled octopole ion trap that is cooled to 5 K. Single-conformation IR and UV spectra are recorded using IR-UV double resonance photofragment spectroscopy. The spectrum of the protonated peptide shown below illustrates the IR spectra so obtained, which probe the hydrogen bonded network present in the ion.

Schematic diagram
Figure 1 Schematic diagram of the cryogenically-cooled ion spectroscopy apparatus
Single-conformation IR spectrum
Figure 2 Single-conformation IR spectrum of the cryo-cooled protonated hexapeptide shown in the inset

Key Contributions

We are using these methods to study a variety of phenomena, including (i) the way in which ions bind and move inside molecular cavities such as the cycloparaphenylenes, (ii) the electronic excited states of ions of relevance to quantum computing, and (iii) electronic energy transfer in chromophore arrays.

PIs: Timothy Zwier, David Chandler