Chemistry Weekly Seminar - Dr. Jennifer van Wijngaarden, University of Manitoba

Title

Spectroscopic fingerprints of astrochemical precursors and targets

Abstract

The molecular composition of astronomical sources, from interstellar clouds to the atmospheres of remote moons, is of great interest as it provides insights into the evolution of our Universe. For example, more than 200 molecular species have been identified in clouds between stars including organic compounds such as alcohols, aldehydes and ketones; some of which are thought to be prebiotic building blocks. Interstellar clouds ultimately form new solar systems and the evolution of their chemical fingerprints can be catalogued using radiotelescopes and compared with laboratory spectra. The observed transitions involve changes in molecular rotation and occur at microwave (MW) through far infrared (FIR) wavelengths. Modern instruments allow spectra in these ranges to be recorded with high spectral resolution (~10–7 and ~10–3 cm–1, respectively) which also provides very accurate and detailed description of fundamental molecular properties such as bond lengths, dipole moments and barriers to tunneling motions. Thus, MW and FIR spectra not only serve as chemical fingerprints but also enhance our understanding of the energy landscape of the individual molecules which is critical to improve theoretical models for the chemical evolution of interstellar objects.  In this talk, I will briefly describe the principles of operation of our two custom-built microwave spectrometers, their capabilities for producing astrochemically relevant species and some recent experimental results. These projects support our FTIR studies at the far infrared beamline at the Canadian Light Source synchrotron. The advantage of using synchrotron radiation as a light source will be described and recent results will be presented.

Date:       Friday, February 26, 2021

Time:     1:30 p.m.

Via Zoom video conference (link available by request to chem.dept@usask.ca)