Cooperative Binding in a Phosphine Oxide-Based Halogen Bonded Dimer Drives Supramolecular Oligomerization

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Chemical Physics

Background:

• Triphenylphosphine oxide acts as a halogen bond acceptor.
• Halogen bonding involves interactions between a Lewis base and an electrophilic region on an halogen atom.
• Understanding halogen bonding is crucial for designing self-assembling molecular systems.

Purpose of the Study:

• To investigate the formation and stability of halogen-bonded complexes.
• To design and synthesize novel self-complementary phosphine oxide-iodotriazole hybrids.
• To explore the cooperative binding effects in self-assembled structures.

Main Methods:

• Computational assessment of complex stability.
• ³¹P NMR spectroscopy in toluene-d₈.
• Synthesis of phosphine oxide-iodotriazole hybrids.
• Analysis of dimer and oligomer formation in solution.

Main Results:

• Triphenylphosphine oxide forms weak halogen-bonded complexes with iodinated compounds.
• Synthesized hybrids self-assemble into stable dimers via halogen-bonded diads in toluene-d₈ and DCM-d₂.
• Cooperative binding significantly enhances the stability of these assemblies.
• Oligomeric assemblies are formed through the aggregation of hybrid units.

Conclusions:

• Self-complementary design enables robust halogen-bonded supramolecular structures.
• Cooperative binding is a key factor in the stability of these assemblies across different solvents.
• This work provides a foundation for developing new materials through controlled molecular self-assembly.