First infrared spectroscopic characterization of digermyl (Ge2H5) and d5-digermyl (Ge2D5) radicals in low temperature germane matrices

The digermyl, Ge2H5(X2A′) and d5-digermyl, Ge2D5(X2A′), radicals were detected for the first time in low temperature germane and d4-germane matrices at 12 K via infrared spectroscopy after an irradiation of the samples with mono energetic electrons. Considering a scaling factor of 0.97, ab initio calculations showed that the most intense absorption of the digermyl radical should be observable for the ν6 fundamental at 770 cm−1 Ge2H5(X2A′) and 547 cm−1 Ge2D5(X2A′), respectively. The actually experimental results (765 cm−1 and 561 cm−1) are in good agreement with these computed data; we also detected the ν4/ν12 mode of the d5-digermyl radical at 616 cm−1. These data may aid in the monitoring of time resolved infrared spectroscopy of germane chemical vapor deposition processes and can also guide prospective observations of germanium-bearing molecules in the atmospheres of Jupiter and Saturn in the infrared regime to better understand the chemical evolution of planetary atmospheres under extreme environments.