ja0426239_si_001.pdf (41.45 kB)
Interstellar Chemistry: A Strategy for Detecting Polycyclic Aromatic Hydrocarbons in Space
journal contribution
posted on 2005-03-30, 00:00 authored by F. J. Lovas, Robert J. McMahon, Jens-Uwe Grabow, Melanie Schnell, James Mack, Lawrence T. Scott, Robert L. KuczkowskiPolycyclic aromatic hydrocarbons (PAHs) have long been postulated as constituents of the
interstellar gas and circumstellar disks. Observational infrared emission spectra have been plausibly
interpreted in support of this hypothesis, but the small (or zero) dipole moments of planar, unsubstituted
PAHs preclude their definitive radio astronomical identification. Polar PAHs, such as corannulene, thus
represent important targets for radio astronomy because they offer the possibilities of confirming the
existence of PAHs in space and revealing new insight into the chemistry of the interstellar medium. Toward
this objective, the high-resolution rotational spectrum of corannulene has been obtained by Fourier transform
microwave spectroscopy, and the dipole moment (2.07 D) of this exceptionally polar PAH has been
measured by exploiting the Stark effect.