"Janus" Calixarenes: Double-Sided Molecular Linkers for Facile, Multianchor Point, Multifunctional, Surface...

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Electrochemistry

Background:

• Calixarenes are versatile macrocyclic hosts with tunable properties.
• Surface modification of electrodes is crucial for developing advanced electrochemical devices.
• Precise control over molecular orientation on surfaces is challenging.

Purpose of the Study:

• To synthesize novel Janus calix[4]arenes for controlled electrode surface functionalization.
• To enable multipoint covalent attachment and monolayer formation on electrode surfaces.
• To demonstrate the ability to decorate calixarene nanocavities with various substrates and connect redox-active species electrically.

Main Methods:

• Synthesis of Janus calix[4]arenes with distinct functional groups on upper and lower rims.
• Utilizing "molecular tethering" groups for covalent attachment to electrode surfaces.
• Employing copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) for facile rim modification.
• Characterization of surface-bound calixarenes and their electrochemical properties.

Main Results:

• Successful synthesis of Janus calixarenes with defined upper/lower rim functionalities.
• Achieved facile multipoint covalent attachment, resulting in monolayer-covered electrodes.
• Demonstrated efficient decoration of calixarene nanocavities with diverse substrates via CuAAC.
• Confirmed electrical connectivity of peripheral redox species to the electrode through the calixarene scaffold.

Conclusions:

• Janus calix[4]arenes provide a robust platform for creating well-defined, functionalized electrode surfaces.
• The synthetic strategy allows for versatile modification and precise control over molecular orientation.
• These tailored nanoreactors hold potential for applications in sensing, catalysis, and molecular electronics.