Tuning and Directing Energy Transfer in the Whole Visible Spectrum through Linker Installation in Metal–Organic Frameworks

Abstract

While limited choice of emissive organic linkers with systematic emission tunability presents ag reat challenge to investigate energy transfer (ET) over the whole visible light range with designable directions,l uminescent metal-organic frameworks (LMOFs) may serve as an ideal platform for such study due to their tunable structure and composition. Herein, five Zr 6 cluster-based LMOFs,HIAM-400X (X = 0, 1, 2, 3, 4) are prepared using 2,1,3-benzothiadiazole and its derivativebased tetratopic carboxylic acids as organic linkers.T he accessible unsaturated metal sites confer HIAM-400X as apristine scaffold for linker installation. Six full-color emissive 2,1,3-benzothiadiazole and its derivative-based dicarboxylic acids (L) were successfully installed into HIAM-400X matrix to form HIAM-400X-L, in whichthe ET can be facilely tuned by controlling its direction, either from the inserted linkers to pristine MOFs or from the pristine MOFs to inserted linkers, and over the whole range of visible light. The combination of the pristine MOFs and the second linkers via linker installation creates ap owerfult wo-dimensional space in tuning the emission via ET in LMOFs.

Dynamic Full‐Color Tuning of Organic Chromophore in a Multi‐Stimuli‐Responsive 2D Flexible MOF

“…Most remarkably, the turnover point was at 120 K, just in coincidence with the temperature demarcation between the vertical and horizontal luminescence transitions of NKU‐128 . Therefore, we reasoned that the flexible MOF skeleton not only dictated the conformational changes of 3‐TPPA, but also transfered the excitation energy from the NDA ligand to the 3‐TPPA moiety via resonance energy transfer [52, 53] (Figure S11). Thus, when cooling from 120 to 80 K, the turnover behavior promoted the energy transfer efficiency to enhance the fluorescence intensity of NKU‐128 , while complementing the thermally activated nonradiative loss when heating from 120 to 300 K, giving rise to the rare “normalized” emission intensity throughout the thermo‐fluoro‐chromic process.…”

Real‐Time In Situ Volatile Organic Compound Sensing by a Dual‐Emissive Polynuclear Ln‐MOF with Pronounced LnIII Luminescence Response

“…The in situ formed 12‐c Eu 9 cluster is coordinatively unsaturated and the terminal H 2 O ligands are susceptible to removal upon activation or competitive coordination substitution [34, 35] . This feature has been previously used in the construction of mixed‐linker Zr‐MOFs [36, 37] . Inspired by this, we consider that adjacent unsaturated Eu 9 clusters could afford potential open metal sites (OMSs) to form similar “open pocket” for installation of specific analytes while shielding the OH quenchers.…”

Unveiling Energy Transfer Mechanisms in Nanographene-Incorporated Metal–Organic Frameworks

“…Specifically, 3D MOFs incorporating nanographene exhibit promising potential as exceptional materials for investigating energy transfer phenomena. These systems enable the unique ability to finely modulate fluorescence while avoiding aggregation-caused quenching (ACQ) issues within the framework. ,− Moreover, the atomically accurate nature of the framework and exact distance (and angle) information are readily available, which can be invaluable to designing bichromophoric systems − and to understanding the complex photophysical processes and pathways, − ultimately unveiling the intrinsic relationship between the structure and properties of nanographene in the framework. Notably, the selection of metal ions plays a crucial role in energy transfer within the MOF structures.…”