The molecular geometry of iron trifluoride from electron diffraction and a reinvestigation of aluminum trifluoride

Abstract

The molecular geometry of iron trifluoride has been determined at 1260 K by gas-phase electron diffraction. Use of a platinum envelope during the experiment prevented the iron trifluoride sample from partial reduction otherwise observed at high temperatures. The molecular geometry of aluminum trifluoride has been reinvestigated at 1300 K. The electron diffraction results for both AlF3 and FeF3 are compatible with planar bond configuration (D3hsymmetry) with bond lengths (rg): Al-F 1.630±0.003 Å and Fe-F 1.763±0.004 Å. Experimental vibrational frequencies support the notion of planarity for aluminum trifluoride. There is no such additional spectroscopic evidence available for iron trifluoride. © 1989 VCH Publishers, Inc.