The high-temperature mass spectrometric method was employed to measure the equilibrium partial pressures of small germanium clusters above liquid germanium contained in a graphite Knudsen cell. These data were combined with new thermal functions, calculated from recent theoretical and spectroscopic molecular parameters, to evaluate the atomization enthalpies and enthalpies of formation of Ge[sub 5]-Ge[sub 8]. Mass spectrometric equilibrium data available in literature were also reevaluated. The following atomization enthalpies, Δ[sub a]H[sub 0][sup o](Ge[sub n],g) and enthalpies of formation Δ[sub f]H[sub 298.15][sup o](Ge[sub n],g), in kJ mol-1, have been obtained: Ge[sub 5], 1313±27 and 548±27, Ge[sub 6], 1649±33 and 583±33, Ge[sub 7], 2008±42 and 598±42, Ge[sub 8], 2359±60 and 618±60. The atomization energies are compared with available theoretical values.
Gingerich, K. A., Gingerich, K., Schmude, R. W., Schmude Jr., R., Sai Baba, M., Baba, M. S., & Meloni, G. (2000). Atomization enthalpies and enthalpies of formation of the germanium clusters, Ge[sub 5], Ge[sub 6], Ge[sub 7], and Ge[sub 8] by Knudsen effusion mass spectrometry. Journal Of Chemical Physics, 112(17), 7443.