Perylene-Based Covalent Organic Frameworks for Acid Vapor Sensing.

Area of Science:

• Materials Science
• Chemistry
• Nanotechnology

Background:

• Covalent organic frameworks (COFs) properties are typically defined by building blocks.
• Chemical bonds within COFs have been overlooked as functional components.

Purpose of the Study:

• To develop novel perylene-based COFs with functional imine bonds.
• To investigate the protonation behavior and sensing capabilities of these COFs.

Main Methods:

• Synthesis of dual-pore perylene-based COFs.
• Protonation studies of imine bonds within the COF structure.
• Fabrication and testing of COF thin films as acid vapor sensors.

Main Results:

• Reversible protonation of imine bonds induced significant color shifts to the near-infrared.
• COF thin films demonstrated high sensitivity to acid vapors (detection limit: 35 μg L⁻¹).
• The acidochromism allowed for simultaneous determination of concentration and protonation strength in nonaqueous solutions.

Conclusions:

• Imine bonds can be incorporated as functional components in COFs.
• These COFs serve as effective colorimetric sensors for acid vapors and nonaqueous solutions.
• This approach expands the multifunctionality and applications of covalent organic frameworks.