Self-assembly of N3-substituted xanthines in the solid state and at the solid-liquid interface.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Chemistry

Background:

• Self-assembly of molecular modules via noncovalent forces is key for functional materials.
• Hydrogen-bonded supramolecular polymers offer geometric control through programmable artificial nucleobases.
• Artificial nucleobases enable precise control over supramolecular architecture via strong hydrogen bonds.

Purpose of the Study:

• To describe N(3)-functionalized xanthine modules for self-assembly.
• To investigate the formation of self-complementary hydrogen-bonding patterns.
• To generate highly compact 1D supramolecular polymeric ribbons on graphite.

Main Methods:

• Utilized N(3)-functionalized xanthine modules.
• Exploited self-complementary hydrogen-bonding patterns for self-association.
• Characterized structures using scanning tunneling microscopy (STM) at the solid-liquid interface.
• Corroborated findings with dispersion-corrected density functional theory (DFT) and X-ray diffraction.

Main Results:

• N(3)-functionalized xanthine modules self-associate through self-complementary H-bonding.
• Formation of highly compact 1D supramolecular polymeric ribbons on graphite.
• Demonstrated controlled generation of specific supramolecular architectures.
• Experimental characterization confirmed the ribbon structures.

Conclusions:

• N(3)-functionalized xanthines are effective building blocks for supramolecular polymers.
• Directional hydrogen bonding enables precise control over 1D supramolecular assembly.
• This work advances the design of functional supramolecular materials through programmable self-assembly.