Germyl, trihydridogermanate(1-), trihydrogermanide, trihydridogermyl or according to IUPAC Red Book: germanide[1] is an anion containing germanium bounded with three hydrogens, with formula GeH−3.
[4] Salt elimination can be used in a reaction with monochlorogermane and a sodium salt of a transition metal anion: In the gas phase, the germyl anion GeH−3 can be made from germane by capturing an electron with more than 8 eV of energy: The germyl radical can be produced and immobilised in molecular form by exposing germane to vacuum ultraviolet light in a solid argon matrix.
[8] The energy to rip a hydrogen atom off germane to make the neutral radical is 82.0 ± 2 kcal/mol (343.1 ± 8.4 kJ/mol).
[5] Both the anion GeH−3 and radical GeH•3 have C3v symmetry, and are shaped as a triangular pyramid with germanium at the top, and three hydrogen atoms at the bottom.
[5] Germyl compounds gradually decompose at room temperature by releasing hydrogen and forming a metal germide.
With aromatic halide compounds, dihalomethanes, or neopentyl haldes they replace the halogen with hydrogen.