Mass spectrometric studies at high temperatures. Part 35.—Stabilities of gaseous GeCl2 and GeBr2

Abstract

Mass spectrometric studies of the equilibrium vapour species for the systems, Ge(s)+ GeCl₄(g) and Ge(s)+ GeBr₄(g), have been conducted using a gas-inlet Knudsen cell. The disproportionation reactions, Ge(s)+ GeCl₄(g)= 2GeCl₂(g)(I) and Ge(s)+ GeBr₄(g)= 2GeBr₂(g)(II) were the only equilibria involved; no polymeric species were observed.

The heats of reactions (I) and (II) were ΔH°_{r, 298}(I)= 40.6 ± 2.0 kcal mole^–1 and ΔH°_{r, 298}(II)= 40.4 ± 1.5 kcal mole^–1. The heats of formation and atomization energies for gaseous GeCl₂ and GeBr₂ were estimated to be ΔH°_{f, 298}[GeCl₂(g)]=–42 ± 1 kcal mole^–1, ΔH°_{f, 298}[GeBr₂(g)]=–13 ± 1 kcal mole^–1, ΔH°_atoms[GeCl₂(g)]= 188 ± 5 kcal mole^–1, and ΔH°_atoms[GeBr₂(g)]= 164 ± 5 kcal mole^–1.