Monofunctionalised cucurbit[6]uril synthesis using imidazolium host-guest complexation.

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Macrocyclic Chemistry

Background:

• Cucurbit[6]uril (CB[6]) is a macrocyclic host molecule with a unique cavity.
• Functionalization of CB[6] is challenging but offers opportunities for new applications.
• Controlled oxidation provides a potential route for selective CB[6] modification.

Purpose of the Study:

• To achieve the first synthesis of monohydroxylated cucurbit[6]uril.
• To investigate the feasibility of chemical modification of the new derivative.
• To characterize the synthesized compound using advanced analytical techniques.

Main Methods:

• Controlled oxidation of cucurbit[6]uril (CB[6]) in the presence of a bisimidazolium guest.
• Nuclear Magnetic Resonance (1H NMR) spectroscopy for structural elucidation.
• Electrospray Ionization Mass Spectrometry (ESI-MS) for molecular weight determination.
• X-ray crystallography for definitive structural confirmation.

Main Results:

• Successful synthesis of monohydroxylated CB[6] was confirmed.
• The presence and position of the hydroxyl group were verified by spectroscopic and crystallographic data.
• The monohydroxylated CB[6] derivative demonstrated susceptibility to further chemical modification.

Conclusions:

• Monohydroxylated CB[6] has been synthesized for the first time.
• The synthetic strategy employing a tailor-made guest during oxidation is effective.
• This new functionalized CB[6] opens avenues for developing novel supramolecular materials and applications.