Electron-diffraction studies on the In-I system. IV. Geometrical configuration, vibrational frequencies, and molecular energetics for indium iodide

A survey is presented on electron diffraction by InI, InI3, In2I6, InInI4 and on the vapor compositions above indium monoiodide, diiodide, and triiodide. The molecular structures are examined and relationships are derived between the structure parameters. Estimates are made for the lacking vibrational frequencies of In2I6, and band assignments are made for InInI4. The electron-diffraction data give the enthalpy and entropy of 2InI3 right-reversible In2I6 and InI + InI3 right-reversible InInI4, from which the heats of formation of gaseous In2I6and InInI4 can be calculated. These molecules show a correlation between the mean bond energies and the structural characteristics. Heats of reaction are derived for reactions involving indium iodides