Knowledge Bank

In 1995, we reported the structure of $GeH2$, based on the assignment of 16 rotational lines in the LIF spectrum of the $000$ band of the $A~1B1-X~1A1$ electronic $transition.a$ The number of observed rotational transitions was severely limited by an inhomogeneous predissociation in the excited state. We have now recorded high resolution LIF spectra of the $000$ band of jet-cooled $GeD2$ using the pulsed discharge technique with a $GeD3Cl$ precursor. The spectrum is much more extensive than that of $GeH2$ due to less efficient tunneling through the barrier dissociation on deuteration. Portions of the room temperature $000$ band absorption spectrum of $GeH2$ have also been studied at Doppler-limited resolution using the laser optogalvanic technique. Rotational analysis of these spectra has provided the ground and excited state rotational constants for several germanium isotopomers. These data have been used to obtain an improved structure for germylene.