论文发表
3. Yong-Kang Zhang, Lan Zhao, Alexander O. Terent’ev,b Liang-Nian He* Dynamic Pyridinethiol Ligand Shuttling within Iron-Anchored Covalent Organic Frameworks Boosts CO2 Photoreduction. J. Mater. Chem. A. 2025, 13, 1407-1419. [Link]
Abstract: Covalent organic framework (COF), as a porous crystalline material, provides a versatile platform for photocatalytic CO2 reduction reaction (PCO2RR). However, the lack of surface redox active sites and rapid photogenerated charge recombination are the major barriers limiting further enhancement of PCO2RR activity. Herein, we designed a novel photocatalytic system constructed from a dynamic D··M-A structure COF. The earth abundant metal iron sites were embedded into the triazinyl COF structure containing bipyridine units (Fe-bpy-COF), and the subsequent supplementation of pyridinethiol to the system allowed efficient CO2 photoreduction without additional photosensitizers. Remarkably, the Fe-bpy-COF system achieved an impressive formate yield of 4052 μmol g-1 h-1 and CO yield of 2123 μmol g-1 h-1, being over approximately 8.2-fold higher than that of the previously reported Re-COF under visible light irradiation. On the basis of 1H NMR titration experiments and steady-state tests of the absorption spectra, the superior photocatalytic performance is accordingly attributed to the dynamic coordination interaction between the pyridinethiol ligands and Fe-bpy-COF host, thus facilitating continuous double-electron transfer from the pyridinethiol ligands to the iron center under visible light and inhibiting photogenerated charge recombination in Fe-bpy-COF. Finally, the reaction pathways of CO2 conversion catalyzed by the reductive iron active species are elucidated by combining experimental results and density functional theory study. This provides unprecedented insights into the design of earth abundant metal-derived COF photocatalysts for efficient and selective CO2 reduction under visible light.
2. Dmitri I. Fomenkov, Roman A. Budekhin, Olga M. Mulina, Olga Komarova, Mikhail M. Doronin, Yulia Yu. Belyakova, Liang-Nian He, Ivan A. Yaremenko, Alexander O. Terent'ev*. Ring Opening and C(ω)-S Coupling: Nickel-Mediated Transformation of Alicyclic Alkoxyhydroperoxides. Eur. J. Org. Chem. 2025, e202401198 [Link]
Abstract: Ozonolysis of cycloalkanone semicarbazones in alcohol containing solution with the subsequent addition of nickel (II) dithiocarbamates or xanthates was found to result in ω-xanthyl or ω-dithiocarbamyl carboxylic acid esters. The reaction proceeds in several steps. The initial one is cycloalkanone semicarbazone ozonolysis in the presence of alcohol, which leads to alicyclic alkoxyhydroperoxide. The second step is an extraordinary interaction between the alkoxyhydroperoxide and nickel (II) dithiocarbamate or xanthate, which proceeds via alkoxy radical formation and its subsequent β-scission, resulting in C-S coupling products. The developed method allows to obtain ω-xanthyl or ω-dithiocarbamyl esters in yields up to 52% relative to the initial cycloalkanone semicarbazone.
1. Zheng-Zheng Meng, Shan-Shan Chen, Hong-Ru Li*, Liang-Nian He*. Heterogeneous Catalysis for Aerobic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid under Base-Free Conditions. ChemCatChem 2024, e202401658. [Link]
Abstract: 2,5-Furandicarboxylic acid (FDCA) is a biomass-derived monomer for the production of poly(ethylene 2,5-furandicarboxylate) (PEF), which is a novel polyester that can serve as a sustainable alternative to traditional petroleum-based poly(ethylene terephthalate) (PET). Currently, the industrial production of FDCA depends on the thermo catalytic aerobic oxidation of 5-hydroxymethylfurfural (HMF) using heterogeneous catalysts in aqueous solution, in which process equivalent homogeneous bases are usually needed to promote the oxidation of hydroxymethyl and aldehyde groups and simultaneously improve the solubility of oxidative products via forming carboxylate. The involvement of massive base causes risks of equipment corrosion and necessitates subsequent product separation and purification with a large amount acid. In this context, the base-free aerobic oxidation of HMF to FDCA has attracted much concern. Nowadays, by developing supported catalysts with multiple catalytic sites, using diluted substrate and finding good solvent for FDCA, much progress has been achieved in this field. This review provides the state of the art of the heterogeneous catalysis for aerobic oxidation of HMF to FDCA under base-free conditions, highlighting the catalytic mechanism to shed light on the catalyst design principles.