Laser spectroscopy of iridium monohydride and iridium monodeuteride

Laser-induced fluorescence spectra of iridium monohydride (IrH) and monodeuteride (IrD) have been obtained at medium resolution. Eight red-degraded bands for each isotopologue were observed. The bands are assigned as Ω′ = 4 − Ω″ = 4 transitions with the ground state common to all bands in each isotopologue. The data are consistent with the ground state being the lowest component of a 3Φi state. A global fit of all the rotationally resolved data yielded a set of rotation and distortion constants for each band. Ground state vibrational frequencies for IrH and IrD were determined to be 2216 and 1610 cm−1.