Computational study of van der Waals complexes between borylenes and hydrocarbons

Area of Science:

• Organometallic Chemistry
• Computational Chemistry
• Chemical Physics

Background:

• Borylenes are reactive species with a divalent boron atom.
• Understanding their interactions with unsaturated hydrocarbons is crucial for synthetic chemistry.
• Previous studies suggest complex formation, but detailed interaction analysis is needed.

Purpose of the Study:

• To investigate the formation and stability of van der Waals complexes between borylenes and simple hydrocarbons (ethyne, ethene, methane).
• To analyze the nature of intermolecular interactions governing these complexes.
• To compare the binding affinities across different hydrocarbon substrates.

Main Methods:

• Geometry optimization using spin-component scaled second-order Møller-Plesset perturbation theory (SCS-MP2) with a def2-QZVP basis set.
• Energy refinement using coupled-cluster (CCSD(T)) methods with quadruple-ζ basis sets (def2-QZVP, aug-cc-pVTZ).
• Interaction analysis using Symmetry-Adapted Perturbation Theory (SAPT).

Main Results:

• Weakly bound van der Waals complexes are identified for borylene additions to ethyne, ethene, and C-H insertion into methane.
• Borylene-ethyne complexes are the most stable, while borylene-methane complexes are the least stable.
• Aminoborylene complexes with ethyne and ethene are stabilized by NH⋅⋅⋅π interactions; electrostatic forces dominate ethyne complexes, while dispersive forces are key for ethene and methane complexes.

Conclusions:

• Borylene interactions with hydrocarbons proceed via shallow potential energy minima corresponding to van der Waals complexes.
• The nature of bonding (electrostatic vs. dispersive) and stability are substrate-dependent.
• These findings provide fundamental insights into borylene reactivity and non-covalent interactions in organometallic chemistry.