Mass spectrometric determination of the dissociation energies of the molecules BiO, BiS, BiSe and BiTe

Abstract

The dissociation energies of BiO, BiS, BiSe and BiTe were determined from equilibrium studies based on the exchange reactions Pb(g)+ BiX(g)= Bi(g)+ PbX(g), where X = O, S, Se or Te and from the known dissociation energies of PbO, PbS, PbSe and PbTe. The values obtained are D°₀(BiO)= 338.9 ± 5.9, D°₀(BiS)= 311.8 ± 4.6, D°₀(BiSe)= 276.5 ± 5.9 and D°₀(BiTe)= 228.5 ± 11.3 kJ mol^–1. These are based on the dissociation energies of the PbX molecules which are discussed : D°₀(PbO)= 374.0 ± 4.2, D°₀(PbS)= 342.3 ± 1.7, D°₀(PbSe)= 299.1 ± 4.2, and D°₀(PbTe)= 246.1 ± 10.5 kJ mol^–1. The latter two also involve a discussion of D°₀(Se₂)= 329.0 ± 0.3 and D°₀(Te₂)= 260.7 ± 0.8 kJ mol^–1.