			15min:

GAS-PHASE ELECTRONIC SPECTRA OF CARBON CHAINS.

D. A. KIRKWOOD, H. LINNARTZ, T. MOTYLEWSKI, M. PACHKOV, M. TULEJ AND J. P. MAIER, Institute of Physical Chemistry, University of Basel, Klingelbergstr. 80, CH-4056 Basel, Switzerland.

Electronic transitions of carbon chains and their ions are being measured in the gas-phase. The neutral species, such as C_nH n=6,8,10, have been observed by cavity ringdown absorption, whearas the carbon anions by a two photon detachment approach. Comparison is made with astronomical data on diffuse interstellar bands. The case of C₇^- is striking; the origin band of the A² _u leftarrow X² _g transition, as well as the strong vibronic transitions, coincide with DIBs. This provides compelling evidence for the first identification of a carrier.