Abstract:
1) The abstract introduces a new metal-organic framework (MOF), UPC-88, designed for chemiluminescence microreactors (CLMR), which demonstrates significantly enhanced light emission compared to traditional solvent systems.
2) UPC-88 incorporates a dual catalytic center for H2O2, integrating a lophine base with a naphthalene chromophore within a single ligand, leading to a reduction in energy transfer path length and improved light emission performance.
3) A record luminous time of up to 1100 minutes for the UPC-88 system was achieved, surpassing previous MOF systems, and a novel linear fit between fluorescence intensity and power was established, marking UPC-88 as the most potent MOF chemiluminescent material reported to date.

Background:
1) Industry Problems: Traditional chemiluminescent agents suffer from brief light emission and weak intensity due to uncontrolled raw material consumption and energy loss through relaxation.
2) Previous Solutions: Previous research has focused on developing coordination CL materials to improve energy transfer efficiency but has not fully addressed the issue of flash-type light emission and raw material supply control.
3) Innovative Ideas: The authors propose a new MOF, UPC-88, with an integrated catalytic and chromophore center within its ligand, and a microporous channel to control H2O2 diffusion, aiming to enhance energy transfer efficiency and luminescence duration.

Experimental Details
1) Synthesis of UPC-88: A solvothermal reaction was used to synthesize UPC-88, using Ba(NO3)2 and H4LIM-2H ligand in a mixed solvent, resulting in colorless bulk crystals.
2) Chemiluminescence Process: The CL performance of UPC-88 was tested using a traditional peroxyoxalate chemiluminescence system, with H2O2 addition leading to bright blue light emission.
3) Optimization of CL Conditions: A series of comparative experiments were conducted to determine optimal CL conditions, including temperature effects and the influence of different reagents on luminescence intensity and duration.

Test and Analysis
1) Fluorescence Intensity and Power: A linear relationship was established between CL intensity and H2O2 addition time, with a high R-square value, indicating UPC-88's efficient control over H2O2 diffusion.
2) Chemiluminescence Quantum Yield: The quantum yield of UPC-88 was measured and compared to standard systems, revealing a higher yield attributed to the MOF's structure and the lophine base catalytic center.
3) Electrocatalysis Decomposition of H2O2: Electrochemical tests confirmed the catalytic efficiency of UPC-88 and the lophine base ligand, showing higher current densities compared to other MOFs.

Conclusion
1) Enhanced CL Performance: UPC-88, a novel Ba-MOF, was successfully synthesized and demonstrated record luminous time and intensity in MOF CL systems, attributed to its integrated catalytic and chromophore centers.
2) Theoretical and Practical Implications: The findings provide a reference for developing next-generation CL microreactors and offer insights into the design of CL systems with improved performance.
3) Future Comparison Method: The standard linear equation obtained allows for the conversion of CL intensity into power for future practical comparisons, a novel approach in the field.
4) It is recommended that the authors investigate the mechanistic understanding of UPC-88 in CL processes and its potential integration into other sensing technologies.


A Precise Microreactor for Ultralong Visible Chemiluminescence
Yutong Wang, Mingyue Fu, Meng Sun, Fugang Li, Fei Gao, Xiaokang Wang, Xinlei Yang, Hongyan Liu, Zhenyu Xiao*, Weidong Fan*, and Daofeng Sun
DOI: 10.1021/acs.chemmater.4c01126
Link: https://pubs.acs.org/doi/10.1021/acs.chemmater.4c01126