Supramolecular recognition on the surface of two-dimensional polyketones

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Two-dimensional polymers (2DPs) are emerging materials with unique properties due to their atomically thin, ordered structures.
• 2DPs offer potential in optics, electronics, and host-guest chemistry.
• Developing synthetic methods for structurally defined 2DPs is crucial for exploring their applications.

Purpose of the Study:

• To synthesize a crystalline two-dimensional polyketone (2D-PK) using a novel interfacial approach.
• To characterize the structure and properties of the synthesized 2D-PK.
• To investigate the host-guest interactions of 2D-PK with organic dyes and assess its potential for molecular recognition and sensing.

Main Methods:

• Synthesis of 2D-PK via Friedel-Crafts acylation at a solid-liquid interface on aluminum foil.
• Structural characterization using SEM, TEM, AFM, HRTEM, IR spectroscopy, solid-state NMR, and PXRD.
• Investigation of host-guest interactions with organic dyes (e.g., methyl green) using fluorescence spectroscopy, NMR, DLS, BET surface area analysis, and UV-Vis absorption.

Main Results:

• Successful synthesis of micrometer-sized, crystalline 2D-PK sheets with highly ordered, stacked layers and an interlayer spacing of 3.54 Å.
• Demonstrated selective supramolecular interactions of 2D-PK with methyl green, leading to significant fluorescence enhancement and spectral shifts.
• Elucidation of host-guest binding mechanisms involving electrostatic attraction, confinement, and charge-transfer interactions, supported by experimental and computational data.

Conclusions:

• Structurally ordered 2D-PKs can be synthesized efficiently via an interfacial Friedel-Crafts acylation method.
• 2D-PKs act as effective platforms for selective molecular recognition, particularly for organic dyes.
• The tunable fluorescence response of 2D-PKs highlights their potential for developing advanced chemical sensors and optoelectronic devices.