Design and Property Modulation of Metal–Organic Frameworks with Aggregation-Induced Emission

Abstract

Fluorogens with aggregation-induced emission (AIEgens) are a unique type of luminescent materials for sensing and imaging applications. The integration of AIE characteristics into metal–organic frameworks (MOFs) structure is an emerging research field that has greatly advanced the optical properties of MOFs. This Review mainly focuses on the development of AIE MOFs with highlights on materials development and their applications in analytical and biomedical fields. The first part discusses the structure design for AIE MOF from the perspective of linkers, metal nodes, and heterogeneous composites. The second part summarizes the major mechanisms on the property modulation of AIE MOFs in response to different stimuli based on fluorescence quenching, in-situ restriction of intramolecular motion, and framework deformation switches. The outlook elaborates on the potential of AIE MOFs, which have opened a new dimension in luminescent material development.

The fast-growing field of photo-driven theranostics based on aggregation-induced emission

“…Organic-inorganic hybrid systems with AIE activity combine the great advantages of inorganic platforms and AIEgens, supporting their high imaging quality and improving their treatment efficacy. 247,248…”

A novel cubic Zn‐citric acid‐based MOF as a highly efficient and reusable catalyst for the synthesis of pyranopyrazoles and 5‐substituted 1H‐tetrazoles

“…spectra of (a) zinc nitrate, (b) citric acid and (c) Zn-CA-MOFs' catalyst not observed in the spectra of the prepared Zn-CA-MOFs, whereas the Zn-CA-MOF spectrum showed two absorption peaks related to the vibration of the C=O bonds of aliphatic carboxylic acid groups at 1560 cm À1 . [44] The carbonyl absorption peak shifts, from 1703 cm À1 in the pure citric acid to the lower wavenumber (1560 cm À1 ) in the final Zn-CA-MOFs, represent the interaction between Zn and citric acid (Figure 1c). In addition, the peaks at the region of 2922-2999 cm À1 are the most important peaks that can be regarded as the characteristic of the aliphatic C─H stretching vibrations.…”

Zinc (II) and AIEgens: The “Clip Approach” for a Novel Fluorophore Family. A Review

“…In 2005, Tang and coworkers produced chemosensors based on silole as sensors for the regioisomers of nitroanilines [ 57 ] and in 2010, Park and coworkers promoted AIEgens as stimuli–responsive materials. To date, several AIE-based chemosensors were reported for the detection of ions, metals, small organic molecules, and biological targets [ 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 ].…”

“…Porous crystalline solids such as inorganic nanoparticles (NPs), metal–organic frameworks (MOFs), covalent organic frameworks (COFs), and carbon nanotubes (CNTs) are materials where the choice of suitable AIE active fragments can produce highly engineered composite materials with unique properties [ 59 , 60 , 61 ]. In the composite material, the AIE moieties interact with a regular structure resulting in tunable electronic and optical properties.…”