Thermal stability and structures of gaseous GeB2O4 and GeMo2O7

Abstract

The stability of gaseous species GeB₂O₄ and GeMo₂O₇ was confirmed by Knudsen effusion mass spectrometry. The gas-phase reactions involving B₂O₃, Mo₂O₆, MoO₃, GeB₂O₄ and GeMo₂O₇ were studied. On the basis of equilibrium constants, the standard formation and atomization enthalpies of gaseous GeB₂O₄ (−1101 ± 18 kJ mol⁻¹ and 3600 ± 20 kJ mol⁻¹) and GeMo₂O₇ (−1449 ± 41 kJ mol⁻¹ and 4810 ± 43 kJ mol⁻¹) at 298 K were determined. To get structure parameters and vibrational frequencies of gaseous GeB₂O₄ and GeMo₂O₇ quantum chemical investigation of these molecules was undertaken. Formation enthalpies of gaseous GeTaO₃, GeTiO₃, GeVO₃ and GePO₂ were estimated.