DISPERSED FLUORESCENCE SPECTROSCOPY OF JET-COOLED DCO

We obtain dispersed fluorescence (DF) spectra of jet-cooled DCO from t hree excited-state levels in the ($) over tilde B(2)A'-($) over tilde X(2)A' system. These spectra yield term energies and relative fluoresc ence intensities for 112 levels (mostly quasibound resonances) of DCO (($) over tilde X) over an energy range of 0-19000 cm(-1). We make zer oth-order, normal-mode vibrational assignments to 99 levels; however, their term energies are not well described by the customary (Dunham) e xpression due to extensive vibrational mixing and the weak C-D bond. T he use of an improved spectroscopic Hamiltonian that includes Fermi re sonance and Darling-Dennison coupling terms is discussed.