Fourier transform-ion cyclotron resonance study of the gas-phase acidities of germane and methylgermane; bond dissociation energy of germane

An accurate gas-phase acidity for germane (enthalpy scale, equivalent to the proton affinity of GeH − 3), δ H° acid(GeH 4) = 1502.0 ± 5.1 kJ mol −1, is obtained by constructing a consistent acidity ladder between GeH 4 and H 2S by using Fourier transform-ion cyclotron resonance spectrometry, and 0 and 298.15 K values for the first bond dissociation energy of GeH 4 are proposed: D° 0(H 3G3-H) = 352 ± 9 kJ mol −1; D°(H 3Ge-H) = 358 ± 9 kJ mol −1, respectively. These results are compared with experimental and theoretical data reported in the literature. Methylgermane was found to be a weaker acid than germane by approximately 35 kJ mol −1: δ H° acid (MeGeH 3) = 1536.6 kJ mol −1.