Introducing a pyrazole/imidazole based hybrid cyclophane: a hydrogen bond sensor and binucleating ligand precursor

Area of Science:

• Supramolecular Chemistry
• Coordination Chemistry
• Organic Synthesis

Background:

• Cyclophanes are macrocyclic compounds with unique structural properties.
• Imidazolium and pyrazole moieties are common in host-guest chemistry and catalysis.
• Designing novel macrocycles is crucial for advancing supramolecular chemistry.

Purpose of the Study:

• To synthesize and characterize a novel cyclophane incorporating imidazolium and pyrazole units.
• To investigate the supramolecular recognition capabilities of the cyclophane.
• To explore the potential of the cyclophane as a ligand precursor for metal complexes.

Main Methods:

• Synthesis of the calix[4]imidazolium[2]pyrazole cyclophane.
• Solid-state characterization using X-ray crystallography.
• Spectroscopic analysis (NMR, IR).
• Synthesis and characterization of the dinuclear NHC-nickel(II) complex.

Main Results:

• Successful synthesis of the calix[4]imidazolium[2]pyrazole cyclophane.
• Demonstration of acetonitrile molecule recognition via hydrogen bonding in the solid state.
• Formation and characterization of a dinuclear N-heterocyclic carbene (NHC)-nickel(II) complex, showcasing its ligand precursor ability.

Conclusions:

• The novel cyclophane exhibits promising supramolecular recognition properties.
• The compound serves as an effective precursor for generating metal complexes.
• This work expands the scope of cyclophane applications in host-guest chemistry and catalysis.