Knowledge Bank

To our knowledge, rotationally resloved triplet-singlet spectra have not been previously reported for any of the triatomic carbenes, silylenes or germylenes, although there has been extensive interest in these species. In this work, jet-cooled laser induced phosphorescence spectra of the $a¯3B1-X¯1A1$ band system of difluorosilylene $(SiF2)$ have been obtained using the pyrolysis jet technique. High resolution, rotationally resolved spectra of three bands have been analyzed yielding the moments of inertia and major spin constants for the triplet state. An excited state $r0$ structure has been obtained which is consistent with various literature ab initio predictions. The abrupt onset of an efficient nonradiative decay process was observed for levels with greater than two quanta of the bending mode in the excited state.