Resonance-Assisted Tetrel Bond

Area of Science:

• Supramolecular Chemistry
• Crystallography
• Computational Chemistry

Background:

• Tetrel bonds (TtBs) are attractive interactions involving group 14 elements.
• Resonance can significantly influence non-covalent interactions.

Purpose of the Study:

• To investigate resonance-assisted tetrel bonds (RATtBs).
• To analyze the structural and electronic factors governing RATtB strength and directionality.

Main Methods:

• Analysis of crystal structures from the Cambridge Structural Database (CSD).
• Quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) calculations.

Main Results:

• Identified and characterized several crystal structures featuring RATtBs.
• Demonstrated that π-electron conjugation/delocalization within a supramolecular ring strengthens TtBs.
• Showed that RATtB strength and directionality are tunable by varying atomic and substituent properties.
• Found that interrupting conjugation significantly weakens the interaction.

Conclusions:

• Resonance plays a crucial role in strengthening tetrel bonds, leading to RATtBs.
• RATtBs exhibit enhanced directionality and shorter bond lengths compared to non-conjugated TtBs.
• The findings provide insights into the design and control of non-covalent interactions in molecular systems.