Modulation of the Host–Guest–Guest Interactions in a Metal–Organic Framework for Multiple Anticounterfeiting Applications

Abstract

Developing fluorescent materials with multiple and tunable emissions under different conditions is necessary to meet the growing demand for optical anticounterfeiting technology. Different modes of fluorescence emission can be obtained by loading multiple fluorescent components into metal–organic frameworks (MOFs) and modulating the interaction among them for multiple anticounterfeiting purposes. Herein, a Cd-based MOF (HNU-60) was constructed as a host to encapsulate both lanthanide ions and carbon quantum dots. Multiple fluorescence emissions can be achieved by modulation of host–guest and guest–guest interaction, which holds promise for multiple anticounterfeiting applications. This work opens the opportunity to construct the hybrid MOF-based materials with controlled fluorescence properties for emerging anticounterfeiting applications in various fields.

Metal Hydrogen-Bonded Organic Framework as a pH Sensor for the Detection of Strong Acids

“…Metal–organic frameworks, as a class of porous materials composed of metal ions and organic linkers, have been paid attention in the field of molecule detection. − Generally, hydrogen bonds play important roles in the construction of materials. , Metal hydrogen-bonded organic frameworks (MHOFs) are constructed by metal and organic ligands, resulting in frameworks containing coordination bonds and hydrogen bonds. , For example, Santanu’s group reported MHOF self-assembly via charge-assisted H-bonding interactions between cationic metal imidazole molecules and anionic diene sulfonates/carboxylates. The MHOFs exhibited the ability of hyperproton conduction which broadens application of MHOFs .…”

Photo-functionalized metal–organic frameworks for anti-counterfeiting applications

“…7c). 83 By the encapsulation of sulfonated rhodamine B into lanthanide MOFs, PMOFs were obtained for anti-counterfeiting with excitation-dependent fluorescence. PMOFs were further dispersed into a photonic crystal matrix with structural colors, thus the multilevel anti-counterfeiting material with excitation-dependent fluorescent and angle-dependent structural colors were realized (Fig.…”

Flexible ligand–Gd dye-encapsulated dual-emission metal–organic framework

“…36 The other consideration is the metal nodes. Transition metal ions are often selected as the metal nodes to prepare MOFs, [37][38][39][40] such as Zn 2+ , Cd 2+ , Cu 2+ , and Fe 3+ . However, ligand-to-metal charge transfer (LMCT) frequently occurs owing to the low energy levels of the metal ions, [41][42][43][44] which interferes with the fluorescence properties of the ligand and/or encapsulated molecules in the host-guest system.…”