Mass spectrometric determination of the dissociation energies of the gaseous rare earth monosulphides

Abstract

The dissociation energies of the gaseous monosulphides NdS, EuS, GdS, HoS, and LuS were determined: D°₀(NdS)= 112.2 ± 3.5; D°₀(EuS)= 85.9 ± 3.5; D°₀(GdS)= 124.5 ± 3.5; D°₀(HoS)= 101.4 ± 3.5; D°₀(LuS)= 120.2 ± 3.5 kcal mole^–1. These dissociation energies, together with the previously measured values for LaS, CeS and PrS were compared with the dissociation energies of the corresponding oxides. The dissociation energies of the remaining rare earth sulphides were estimated on the basis of this comparison: D°₀(SmS)= 92.6 ± 5.0; D°₀(TbS)= 122.4 ± 5.0; D°₀(DyS)= 98.1 ± 5.0; D°₀(ErS)= 99.2 ± 5.0; D°₀(TmS)= 86.9 ± 5.0; D°₀(YbS)⩽38.8 kcal mole^–1.