Tunable Far-IRLaser Spectroscopy of Jet-Cooled Carbon Clusters: the ν 2 Bending Vibration of C 3

Abstract
Seven rovibrational transitions of the (01 1 0) ← (00 0 0) fundamental bending band of C3 have been measured with high precision with the use of a tunable far-infrared laser spectrometer. The C3 molecules were produced by laser vaporization of a graphite rod and cooled in a supersonic expansion. The astrophysically important ν 2 fundamental frequency is determined to be 63.416529(40) cm -1 . These measurements provide the basis for studies of C3 in the interstellar medium with far-infrared astronomy.