40min:

J. P. MAIER, Institute for Physical Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland.

The electronic spectra of neutral carbon chains, their anions and cations are being observed in the gas-phase. Three different approaches are used. The transitions of the chain radicals, C_nH n=6,8,10 have been detected by cavity ring down spectroscopy in a slit jet discharge. Carbon chain anions of the type C_n^-, C_nH^- have been studied by a two colour resonant photodetachment approach. The electronic transitions of the polyacetylene cations, like HC₆H⁺ and its cyanoderivative HC₄CN⁺, have been measured at high resolution in cell and jet discharges using frequency modulation absorption spectroscopy.