Mass-spectrometric study of (indium + chlorine)(g). Enthalpies of formation of InCl(g), In2Cl2(g), In2Cl4(g), InCl3(g), and In2Cl6(g)

Article abstract of DOI:10.1016/0021-9614(88)90039-0

The gaseous phase in equilibrium with InCl(s or l), InCl2(s or l), or InCl3(s) was analysed by the Knudsen-cell mass-spectrometric method.InCl3(g) and In2Cl6(g) are the main species vaporizing from InCl3(s); InCl(g), In2Cl2(g), In2Cl4(g), and InCl3(g) from InCl(s or l); and In2Cl4(g), InCl3(g), InCl(g), In2Cl6(g), and In2Cl2(g) from InCl2(s).The gas-phase analysis was performed by studying the ionization-efficiency curves and ionic-intensity ratios as a function of the temperature of vaporization and chemical composition in (indium + chlorine) for every In_xCl_y⁺ ion (x = 1, 2 and y = 0 to 5).Enthalpies of formation were deduced from vaporization and gas-phase equilibria: Δ_fH⁰_m(InCl3, g, 298.15 K) = -(375.7 +/- 5.0) kJ * mol^-1, Δ_fH⁰_m(In2Cl6, g, 298.15 K) = -(883.7 +/- 10.0) kJ * mol^-1, Δ_fH⁰_m(InCl, g, 298.15 K) = -(68.2 +/- 4.6) kJ * mol^-1, Δ_fH⁰_m(In2Cl4, g, 298.15 K) = -(573.2 +/- 12.6= kJ * mol^-1.A lower bound was calculated for InCl2(g): Δ_fH⁰_m(InCl2, g, 298.15 K) >/= -201 kJ * mol^-1.