A Multistimuli Responsive, Flexible Luminescent Framework and Its Applicability in Anticounterfeiting

Abstract

A linear distyrylanthracene derivative (DDATAn) with two diaminotriazine (DAT) groups acting as the hydrogen bond (H-bond) units was designed and synthesized in order to construct flexible organic porous crystals. H-bonds between the DAT moieties helped the molecules to construct a double interpenetrated two-dimensional layer, and the stacking between layers provided a H-bonded organic framework (X-HOF-3) with one-dimensional solvent channels. When X-HOF-3 was placed in contact with methanol, the fluorescent colors of the HOF exhibited an apparent bathochromic shift. More interestingly, the methanol-activated HOF was able to rapidly adsorb water from the air, which was accompanied by a change in fluorescent color from yellow to red. Under heating, water was released from the HOF and the fluorescent color returned to yellow. Water molecules in the pores were also able to be released after an applied mechanical force disrupted the ordered structure of the HOF. Based on these stimuli-responsive properties, these HOFs can be used as advanced functional materials in anticounterfeiting applications.

Luminescent Porous Organic Crystals for Adsorptive Separation of Toluene and Methylcyclohexane

“…374 nm, similar to that in Tol solution, suggesting the potential presence of weak π-stacking within the crystal structure. The crystals emitted cyan fluorescence with a maximum of 477 nm, further suggesting the occurrence of weak π–π interactions …”

In situ generated dimethylamine constructs a robust hydrogen-bonded organic framework for selective fluorescence detection

“…1 HOFs represent a class of crystalline framework structures formed by intermolecular hydrogen bonds between organic or metal-containing molecules, assembled through the synergistic action of other non-covalent interactions such as π–π stacking. 2 Current research efforts focus on these aspects, propelling advancements in various fields including dye adsorption and degradation, 3,4 proton conduction, 5,6 catalysis, 7,8 luminescence phenomena, 9,10 anti-counterfeiting and sensing technologies, 11–16 biological applications, 17–20 gas separation processes, 21,22 enantiomer resolution and separation of aromatic compounds, 23 etc. Since the beginning of the 21st century, MOFs have experienced explosive development, while COFs have recently entered a stage of rapid growth.…”