Real-time optical and electronic sensing with a β-amino enone linked, triazine-containing 2D covalent organic framework

Abstract

Fully-aromatic, two-dimensional covalent organic frameworks (2D COFs) are hailed as candidates for electronic and optical devices, yet to-date few applications emerged that make genuine use of their rational, predictive design principles and permanent pore structure. Here, we present a 2D COF made up of chemoresistant β-amino enone bridges and Lewis-basic triazine moieties that exhibits a dramatic real-time response in the visible spectrum and an increase in bulk conductivity by two orders of magnitude to a chemical trigger - corrosive HCl vapours. The optical and electronic response is fully reversible using a chemical switch (NH 3 vapours) or physical triggers (temperature or vacuum). These findings demonstrate a useful application of fully-aromatic 2D COFs as real-time responsive chemosensors and switches.

High‐Sensitivity Acoustic Molecular Sensors Based on Large‐Area, Spray‐Coated 2D Covalent Organic Frameworks

“…[ 1,2 ] This combination of properties makes 2D COFs promising for a variety of applications, including nanofiltration membranes, [ 3–5 ] charge‐storage devices, [ 6–8 ] and chemical sensors. [ 9–16 ] Despite this promise, conventionally isolated polycrystalline 2D COF powders are insoluble and effectively unprocessable, which have limited their integration into thin‐film device architectures. [ 17–19 ] This limitation has inspired the exploration of numerous thin‐film fabrication approaches, including direct polymerization on substrates, [ 20,21 ] continuous flow methods, [ 22–24 ] interfacial polymerization, [ 3,25,26 ] and electrophoretic deposition.…”

Trendbericht: Makromolekulare Chemie

“…Wie das Forschungsteam zeigte, beruht die Sensorfähigkeit des Materials auf Protonierung des eingebauten Triazin-Elektronenakzeptors. 29) Die Gruppen um von Hauff und Pammer überführten konjugierte Poly(pyridin)e und Poly(p-phenylen-pyrazinylen)e durch Hydroborierung in Leiterpolymere. Durch das Boran lassen sich sowohl die optische Bandlücke als auch die Elektronenaffinität über einen weiten Bereich variieren.…”

Rational Fabrication of Crystalline Smart Materials for Rapid Detection and Efficient Removal of Ozone

“…Moreover, ozone decomposition can be accelerated by initiators such as OH − which can be generated by the protonation of imine groups with water molecules [38–40] . Usually, alteration of the chemical environment of functional groups (e.g., imine) will affect the optical band gaps of materials in the visible part of the spectrum, thus causing the color change [35, 41] . Therefore, imine can be an ideal responsive group for ozone‐related applications.…”