Dual Intrareticular Oxidation of Mixed-Ligand Metal–Organic Frameworks for Stepwise Electrochemiluminescence

Abstract

This work presents a mixed-ligand metal−organic framework (m-MOF) integrated with two ligands, one as a luminophore and the other as a coreactant, on one metal node for self-enhanced electrochemiluminescence (ECL). Both 9,10-di(pcarboxyphenyl)anthracene (DPA) and 1,4-diazabicyclo[2.2.2]octane (D-H 2 ) ligands can be oxidized, generating the cation radicals DPA +• and D-H 2 +• , respectively. The latter can be deprotonated to form the neutral radical (D-H • ) and then react with DPA +• to produce excited DPA* for ECL emission without exogenous coreactants. As a result of the incorporation into the MOF framework and the intrareticular charge transfer between the two ligands, the ECL intensity of the m-MOF was increased 26.5-fold compared with that of the mixture of DPA and D-H 2 in aqueous solution. Moreover, with the process of second oxidation of D-H 2 , stepwise ECL emission was observed as a result of local excitation in the DPA unit, which was identified through density functional theory calculations. Overall, the implementation of the mixed-ligand approach, which combines the luminophore and coreactant as linkers in reticular materials, enriches the fundamentals and applications of ECL systems.

Intrareticular charge transfer regulated electrochemiluminescence of donor–acceptor covalent organic frameworks

“…For example, an electron transfer between Au nanocluster emitters and the grafted N,N-diethylethylenediamine coreactants was accelerated to drastically enhance ECL 11 . In our previous work, a stepwise-oxidation induced intrareticular electron transfer based on 1,4-diazabicyclo[2.2.2]octane coordinated metal-organic framework was established for ECL enhancement 12 . These works improved ECL performance by shortening the distance between emitter and coreactant, thus an efficient charge transfer between the emitter and coreactant was realized.…”

“…In most cases, the emitters such as small molecules and nanocrystals are transformed into excited states through an intermolecular charge transfer process [5][6][7][8][9] . Alternatively, by integrating coreactants with emitters, the resultant systems can undergo intramolecular charge transfer to enhance ECL [10][11][12] . For example, an electron transfer between Au nanocluster emitters and the grafted N,N-diethylethylenediamine coreactants was accelerated to drastically enhance ECL 11 .…”

Post‐Synthetic Modification of Metal‐Organic Frameworks Bearing Phenazine Radical Cations for aza‐Diels‐Alder Reactions

“…The main peaks of 6.4°, 9.1°, 10.2°, 14.3°, 18.3°, and 19.3°showed in the PXRD pattern of N were totally consistent with the simulated pattern based on the crystallographic analysis data of MOF N and the similar MOFs which have been reported in the literature. [47,48] Furthermore, the scanning electron microscope (SEM) image revealed the well-defined block-shaped crystals of MOF N (Figure S6).…”

Progress in spectrum-based electrochemiluminescence quantitative analysis

“…Huang等 [80] . 不含毒性元素的ECL试剂开发已经引起研究人员 的广泛兴趣 [89] , 如铜簇 [90] 、P-dots [91,92] 、C 3 N 4 [93,94] 与有 机金属框架物质 [95] . Long等 [97] .…”