THE MILLIMETER-WAVE SPECTRA OF THE HCCCO AND DCCCO RADICALS

The bent-chain radicals HCCCO and DCCCO have been identified from laboratory measurements of pure rotational transitions between 81 and 400 GHz, sampling Ka = 0 through 3. The spectral frequencies have been fitted to an S-reduced effective Hamiltonian, incorporating the spin-rotation interaction, with distortion terms up to 8th-order in N. The spectroscopic constants so determined indicate that HCCCO and DCCCO are highly prolate asymmetric tops with considerable coupling between bending vibrations and rotation about the a-axis. A preliminary discussion of the structure is presented. © 1992.