Pyrolysis jet spectroscopy and ab initio studies of the S1 and T1 states of germanium difluoride

Spectra of jet-cooled germanium difluoride were obtained by the reaction of germanium metal and fluorine in the throat of a heated supersonic jet. Two band systems at 331–305 and 231–224 nm were observed by laser-induced emission excitation spectroscopy. On the basis of high quality ab initio predictions of the energies, geometries and vibrational frequencies of the lower electronic states, the two band systems are assigned as ã 3B1–X̃ 1A1 and à 1B1–X̃ 1A1, respectively. The T1–S0 spectrum consists of a long, well-resolved progression in the excited state bending frequency with ν2′ = 192.2 cm−1 and T00=30 582.1 cm−1. The S1–S0 spectrum is a complex tangle of vibronic structure accompanied by a rising background. A partial analysis of the vibronic structure gave ν2′ = 159.6 cm−1 and T00=43 860.9 cm−1. The spectra are very similar to the analogous band systems of GeCl2.