Introducing a Pyrazinoquinoxaline Derivative into a Metal–Organic Framework: Achieving Fluorescence-Enhanced Detection for Cs⁺ and Enhancing Photocatalytic Activity

Abstract

Conventional photoresponsive materials have low photon utilization due to irregular distribution of photoactive groups, which severely limits the related real applications. Metal− organic frameworks (MOFs) can modulate the regular arrangement of functional groups to improve the electron transport paths and enhance the photon utilization, which provides strong support for the development of photoactive materials with excellent performance. In this work, one effective strategy for constructing a photoactive MOF had been developed via the utilization of Cd 2+ and pyrazinoquinoxaline tetracarboxylic acid. The structural advantages of the Cd-MOF, such as a porous structure, abundant subject-object interaction sites, and a stable framework, ensure the prerequisite for various applications, while the better synergistic effect of Cd 3 clusters and the pyrazinoquinoxaline derivative ensures efficient electron transfer efficiency. Therefore, by virtue of these structural advantages, the Cd-MOF can achieve fluorescence quenching detection for a variety of substrates, such as Fe 3+ , Cr 2 O 7 2− , MnO 4 − , nitrofuran antibiotics, and TNP explosives, while fluorescence enhancement detection can be achieved for halogen ions, Cs + , Pb 2+ , and NO 2 − . In addition, the Cd-MOF can be used as a photocatalyst to successfully achieve the photocatalytic conversion of benzylamine to N-benzylbenzimidate under mild conditions. Thus, the Cd-MOF as a whole shows the possibility of application as a diverse fluorescence detection and photocatalyst and also illustrates the feasibility of preparing high-performance photoactive materials using the pyrazinoquinoxaline derivative.

A self-assembled metal–organic framework for enhanced UO22+ fluorescence sensing: integration of an octa-nuclear zinc cluster with hexakis(4-carboxyphenoxy)cyclotriphosphazene

“…Nuclear energy, as a highly efficient and clean energy source, has received widespread attention due to its safety and environmental impact. 1–3 The monitoring of uranyl ions (UO 2 2+ ) is crucial for the prevention of nuclear accidents and environmental pollution. 4–6 Meanwhile, iron ions (Fe 3+ ) play a key role in living organisms, and their deficiency affects haemoglobin synthesis and many physiological functions.…”

A D–A–D-type di-lophine derivative-based photoactive metal–organic framework: fluorescence sensing of UO22+ and photochromic behavior

“…Since some of them play an indispensable role in many aspects, their trace detection is crucial. 6–12…”