Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF)

Abstract

Covalent Organic Frameworks (COFs), an emerging class of crystalline porous materials,are proposed as anew type of support for grafting lanthanide ions (Ln 3+ )a nd employing these hybrid materials as ratiometric luminescent thermometers.ATpBpy-COF-prepared from 1,3,5-triformylphloroglucinol (Tp) and 2,2'-bipyridine-5,5'-diamine (Bpy) grafted with Eu/Tb and Dy acetylacetone (acac) complexes can be successfully used as al uminescent thermometer in the 10-360 K( Eu) and 280-440 K( Tb) ranges with good sensing properties (thermal sensitivity up to 1.403 %K À1 ,t emperature uncertainty dT < 1Kabove110 K). Forthe Eu/Tb systems,we observe an unusual and rarely reported behavior,t hat is,n o thermal quenching of the Tb 3+ emission, aresult of the absence of ion-to-ligand/host energy back-transfer.T he LnCOF materials proposed here could be anew class of materials employed for temperature-sensing applications following up on the wellknownluminescent metal-organic framework thermometers.

Luminescent Ratiometric Thermometers Based on a 4f–3d Grafted Covalent Organic Framework to Locally Measure Temperature Gradients During Catalytic Reactions

“…This concept can be further extended to other d‐metals (see SI Figure S22 and S23 for thermometry results using Eu,Tb@TTA‐DFP COF@Ni compound, it was observed that also here the presence of the metal and solvents had a significant influence on the thermometry properties and could be used to design a thermometer with performance in the desired temperature and sensitivity range) as well as other COF platforms giving a wide versatility of possible catalytic reactions and thermometric ranges. As we have shown in our previous work the use of LnCOFs for thermometry is even more promising then the very attractive up until now LnMOFs and shows many possibilities for combining research fields such as thermometry with catalysis [31, 52–54] …”

“…Covalent organic frameworks (COFs) are an emerging class of crystalline porous materials, which have already shown massive potential in catalysis, gas adsorption and storage, batteries, and drug delivery [23–29] . Recently, some of us have reported the first lanthanide‐grafted COF for white light applications, and shortly afterwards the use of lanthanide‐grafted COFs for luminescence thermometry applications, proving its potential also in luminescence applications [30, 31] . Reticular chemistry allows predicting and tuning the crystalline structure by thoughtful selection of the molecular building blocks [32, 33] .…”

N‐Rich Porous Polymer with Isolated Tb3+‐Ions Displays Unique Temperature Dependent Behavior through the Absence of Thermal Quenching

“…temperature dependent). This peculiar temperature behavior was observed only once before [16] . To explain this unique behavior, we hypothesized the absence of Tb‐to‐ligand energy back transfer, resulting in no temperature quenching of Tb 3+ .…”

“…In 2020, some of us (A. M. Kaczmarek et al.) were the first to successfully use a crystalline, porous organic antenna (bipyridine‐based covalent organic framework (TpBpy COF)), as a temperature sensor, in which the nitrogen rich building blocks create an ideal complexation environment for lanthanide ions [16] . This material showed unique and unusual temperature dependent behavior where no thermal quenching was observed for the terbium (Tb 3+ ) ions as a result of the absence of energy transfer from terbium (Tb 3+ ) to europium (Eu 3+ ).…”

Nanoscale covalent organic frameworks as theranostic platforms for oncotherapy: synthesis, functionalization, and applications

“…351 At present, monomers containing coordination sites can be categorized into four types ( Fig. 63A): porphyrin, 352-355 2,2 0bipyridine, [356][357][358][359] catechol, 360,361 and 5,6,11,12,17,18- 362 In general, COF metallization can be readily achieved by simply mixing COFs with metal salts or metal complexes to trigger metal coordination reactions or ligand exchange reactions. Therefore, even metal carbonyl complexes with poor stability can be xed in the COF pores.…”