Aromatic cation-π induced multifluorescence tunable two-dimensional co-assemblies for encoded information security

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Photophysics

Background:

• Light-emitting two-dimensional co-assemblies (2DCAs) are a rapidly advancing field.
• Developing multifluorescence tunable 2DCAs remains challenging due to difficulties in exploring novel assembly strategies and noncovalent interactions for desired photophysical properties.

Purpose of the Study:

• To present the first aromatic cation-π interaction induced emissive charge transfer strategy for multifluorescence tunable 2DCAs.
• To demonstrate the fabrication of programmable patterns with information security functions.

Main Methods:

• Utilized fluorophore anthracene-based monomers and planar aromatic cations (pyrylium, tropylium).
• Exploited aromatic cation-π interactions to form well-regulated 2DCAs.
• Varied solvent ratios to control emissive charge transfer and tune fluorescence emission.

Main Results:

• Achieved a broadened fluorescence tunable range from blue-green to red emission.
• Demonstrated control over assembly/disassembly states to modulate emission properties.
• Successfully fabricated programmable numbers, letters, patterns, and 3D codes with co-assembly encoded information security functions on paper.

Conclusions:

• The aromatic cation-π interaction induced emissive charge transfer strategy is effective for creating tunable multifluorescence 2DCAs.
• This approach offers a simple method for broad color tuning and developing supramolecular encryption materials.