The joint gas electron diffraction and mass spectrometric study of GeI 4(g) + Ge(s) system. Molecular structure of germanium diiodide

Abstract

A mass spectrometric study was made of the GeI 4(g) + Ge(s) system at 400–780 K. The conditions at which GeI 2 is the main molecular species were determined. The electron diffraction patterns were recorded at 653 K with simultaneous mass spectrometric control of the vapour composition. The experimental molecular scattering intensity function was represented using the bond distances, force constants, and the concentrations of the molecular species present in the vapour. It was established that GeI 2 has a non-linear geometry with r α (GeI) = 254.0(5) pm and a valence angle of 102.1(1.0)°. The correlations between the mean bond energies, the bond distances and the valence force constants of the germanium dihalides and tetrahalides are discused.