He@Mo(6)Cl(8)F(6): a stable complex of helium

Area of Science:

• Computational Chemistry
• Inorganic Chemistry
• Quantum Chemistry

Background:

• Endohedral helium clusters are rare and their electronic properties are not well understood.
• Molybdenum-based clusters offer unique electronic and structural characteristics.
• Understanding bonding in such systems is crucial for predicting stability and reactivity.

Purpose of the Study:

• To investigate the electronic structure of the endo helium cluster, He@Mo(6)Cl(8)F(6).
• To determine the chemical stability of this novel cluster.
• To analyze the nature of the bonding between helium and the molybdenum cluster.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Electronic structure and bonding analyses were performed.
• Dissociation energy barriers were calculated to assess stability.

Main Results:

• The He@Mo(6)Cl(8)F(6) cluster shows significant deviation from typical van der Waals systems.
• A short bond distance (1.89 Å) between helium and molybdenum was observed.
• Considerable charge and bond order were found on the helium atom, indicating strong He-Mo interaction, though not covalent.

Conclusions:

• The He@Mo(6)Cl(8)F(6) cluster is chemically stable, with a dissociation barrier of 0.86 eV.
• The bonding is analogous to He@adamantane, suggesting a non-covalent, yet strong, interaction.
• Comparison with the isoelectronic [Mo(6)Cl(8)F(6)](2-) system provides further insight into electronic configurations.