The Tetrel Bonds of Hypervalent Halogen Compounds

Area of Science:

• Computational chemistry
• Quantum chemistry
• Supramolecular chemistry

Background:

• Tetrel bonds are non-covalent interactions involving Group 14 elements.
• Understanding tetrel bond characteristics is crucial for designing novel materials and catalysts.
• The influence of halogen substituents on tetrel bond strength requires further investigation.

Purpose of the Study:

• To investigate the tetrel bond between PhXF2Y(TF3) and MCN electron donors.
• To analyze the effect of halogen electronegativity on tetrel bond strength.
• To explore the enhancement of tetrel bonds involving silicon.

Main Methods:

• Density functional theory (DFT) calculations using the M06-2X functional.
• Basis set employed: aug-cc-pVDZ.
• Systematic variation of halogen substituents (X and Y) and metal centers (M).

Main Results:

• Tetrel bond strength increases with the electronegativity of halogen X but decreases with the electronegativity of halogen Y.
• Most carbon-based complexes exhibited interaction energies below 10 kcal/mol.
• Silicon-based complexes showed significantly enhanced tetrel bonds (up to ~100 kcal/mol) with covalent Si-N interactions, inversion, and potential transfer.

Conclusions:

• The nature and position of halogen substituents critically influence tetrel bond strength.
• Silicon-based tetrel bonds are considerably stronger than their carbon counterparts, exhibiting covalent character.
• These findings provide insights into the factors governing non-covalent interactions and their potential applications.