Synchrotron-based rotationally resolved high-resolution FTIR spectroscopy of azulene and the unidentified infrared bands of astronomy.
Chasing the unidentified IR bands: The first rotationally resolved high-resolution infrared spectrum of azulene is reported using synchrotron Fourier transform infrared spectroscopy including a rovibrational analysis of the out-of-plane fundamental ν44. Comparison of azulene, naphthalene, indole, and biphenyl infrared bands leads to coincidences with UIR bands at 12.8 μm with naphthalene and at 13.55 and 14.6 μm with biphenyl bands, but excluding azulene as a strong absorber.
Physical Chemistry, ETH Zurich, 8093 Zürich (Switzerland). albert@ir.phys.chem.ethz.ch.
Sieghard
S
Albert
Philippe
P
Lerch
Martin
M
Quack
azulene; biphenyls; high‐resolution IR spectroscopy; synchrotron radiation; unidentified infrared bands (UIBs)