Article révisé par les pairs
Résumé : The dissociation energies of the following gaseous monoselenides and tellurides were determined: D0°(LaSe)=472±15; D 0°(NdSe)=379±15; D0°(EuSe)=297±15; D0°(GdSe)=426±15; D0°(HoSe)=329±15; D0°(LuSe)=414±15; D0°(LaTe)=378±15; D0°(NdTe)=301±15; D0°(EuTe)=237±15; D0°(GdTe)=337±15; D0°(HoTe) ≤255±15; D0°(LuTe)=321±15 kJ mol-1 The dissociation energies of the remaining rare earth chalcogenides, Yb excepted, were estimated by comparison with the oxides and sulphides. They are: D o°(CeSe)=473±20; Do°(PrSe)=410±20; D0°(SmSe)=310±40; D0°(TbSe)=419±20; D0°(DySe)=318±20; D0°(ErSe)=322±20; D0°(TmSe)=270±40; D0°(CeTe)=385±20; D0°(PrTe)=322±20; D0(SmTe)=230±40; D0°(TbTe)=332±20; D0°(DyTe)=230±20; D0°(ErTe)=234±20; D0°(TmTe)=182±40; kJ mol-1.