A stable 3D Sr-MOF as an efficient heterogeneous catalyst for the cycloadditions of CO2 and knoevenagel condensation reactions

• Published in: Journal of molecular structure 2024-05, Vol.1303, p.137466, Article 137466
• Main Authors: Xiong, Peng, Xie, Ting-Ting, Zhou, Mi, Li, Shi-Ming, Wang, Xiu-Jian, Ni, Qing-Ling, Gui, Liu-Cheng
• Format: Article
• Language: English
• Subjects: Acylamide-functionalized metal-organic framework; CO2 fixation reaction; Heterogeneous catalyst; Knoevenagel condensation reaction; Stability
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2023.137466

•The one reported stable MOF exhibit structure with 3D framework.•Sr-MOF is explored as stability properties for durable in aqueous environments of pH 1 and 12, as well as organic solvents and different temperature thermal air.•Sr-MOF is explored as an effective catalyst for the cycloaddition reaction of CO2 with epoxides into cyclic carbonates and Knoevenagel condensation reactions of aldehydes and malononitrile.•The synergistic catalysis of lewis acidic Sr2+ions, lewis basic -NH- groups and hydrogen bond donors of -NH- could play an efficient role in cycloaddition reaction and Knoevenagel condensation reactions of aldehydes and malononitrile. The catalytic activity of MOF is determined not only by its unique structure but also by the active sites from metal sites and functional ligands. A sTable 3D strontium complex, {[Sr2(BTCB)Cl(H2O)2]}n (Sr-BTCB), was synthesized under solvothermal condition. It is assembled with an amide-functionalized tricarboxylic acid and a Sr(II)-based infinite chain, where Sr2 repeating units are arranged sequentially. Two such 3D structures are interwoven to create a two-folded interpenetrated structure. The interpenetrated structure is strengthened by π-π interstacking between the central phenyl rings of ligands from different 3D structures. After solvent exchange and vacuum drying, the surface of nanochannels in desolvated Sr-BTCB is modified by unsaturated Sr2+ions. Complex Sr-BTCB has abundant Lewis acidic metal sites and Lewis basic sites of amide groups, as well as 1D rhombic channels. It exhibits excellent stability and heterogeneous catalysis on CO2 fixation reactions into cyclic carbonates and Knoevenagel condensation reactions of aldehydes and malononitrile. [Display omitted] A metal-organic frameworks (MOFs) which were solvothermally synthesized based on alkaline earth metal ion of Sr2+ and a C3-symmetric ligand 4,4′,4″-[1,3,5-benzotriyltris(carbonylimine)]-tris(benzoic acid) (H3BTCB), The Sr-MOF is explored as a catalyst for the cycloaddition reaction of CO2 with epoxides into cyclic carbonates and Knoevenagel condensation reactions of aldehydes and malononitrile.