Molecular geometry of vanadium dichloride and vanadium trichloride: a gas-phase electron diffraction and...

Area of Science:

• Inorganic Chemistry
• Computational Chemistry
• Physical Chemistry

Background:

• Understanding the molecular structures of transition metal halides is crucial for predicting their chemical behavior.
• Previous studies on vanadium chlorides were limited, necessitating further investigation.

Purpose of the Study:

• To determine the precise molecular geometries of vanadium dichloride (VCl2) and vanadium trichloride (VCl3).
• To investigate the vapor composition during VCl2 evaporation.
• To explore the electronic states and symmetry of VCl3.

Main Methods:

• Gas-phase electron diffraction (ED) for experimental structural determination.
• Computational chemistry methods for theoretical analysis and geometry optimization.
• Analysis of vapor composition from solid VCl2 evaporation.

Main Results:

• Vanadium dichloride (VCl2) was found to be linear in its ground electronic state.
• Vanadium trichloride (VCl3) exhibits Jahn-Teller distortion, with C(2v) and D(3h) symmetries being energetically close.
• The vapor phase over solid VCl2 contains approximately 66% VCl3 and 34% VCl2.
• Several low-lying electronic states of VCl3 are anticipated in high-temperature vapor.

Conclusions:

• This is the first combined experimental and computational study of VCl3.
• The dynamic Jahn-Teller effect in VCl3 complicates the definitive assignment of its equilibrium structure.
• The findings provide fundamental insights into the structures and properties of vanadium chlorides.