LABORATORY SPECTROSCOPY OF THE $C_{7}H$ AND $C_{2}H$ RADICALS

The linear carbon chain radicals $C_{7}H$ and $C_{8}H$ have been detected in their $^{2}H$ electronic ground states in an acetylene/argon discharge. For each radical, both spin-orbit components have been detected, precise values for the rotational, fine structure, and lambda-doubling constants determined, and the entire fine structure-rotational spectrum calculated. The lowest. rotational transitions of $C_{7}H$ and $C_{8}H$ were also observed in a pulsed discharge supersonic molecular beam source by Fourier transform microwave spectroscopy. A summary of results. including an analysis of the hyperfine structure will be presented.