An unprecedented cobalt( ii )-containing Wells–Dawson-type tungstovanadate-based metal–organic framework as an efficient catalyst for ring-opening polymerization of ε-caprolactone

• Published in: CrystEngComm Vol. 22; no. 21; pp. 3656 - 3663
• Main Authors: Shen, Nan, Tian, Feng, Chang, Jun, Huang, Kun-Lin, Zhang, Zhi-Hui, Feng, Xuejun, Gu, Jiande, Chen, Sheng-Chun, He, Ming-Yang, Chen, Qun
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 07.06.2020
• Subjects: Catalysts; Catalytic activity; Cobalt; Coordination polymers; Crystal structure; Crystallography; Diamonds; Infrared spectroscopy; Metal-organic frameworks; NMR; Nuclear magnetic resonance; Polonium; Polymerization; Polyoxometallates; Ring opening polymerization; Structural analysis; Triazoles; X ray photoelectron spectroscopy
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/D0CE00309C

By utilizing a flexible fluorinated bis(triazole) ligand 1,4-bis(1,2,4-triazole-1-ylmethyl)-2,3,5,6-tetrafluorobenzene (Fbtx), a thermally and chemically stable cobalt( ii )-containing tungstovanadate-based metal–organic framework (MOF) {[Co 3 (Fbtx) 5 (V 2 W 18 O 62 )(H 2 O) 2 ]·26H 2 O} n (denoted as CZU-5) was synthesized and structurally characterized. The X-ray structural analysis revealed that CZU-5 features a three-dimensional (3-D) self-penetrated α-polonium cubic structure, which results from a 3-D 4-fold interpenetrated diamondoid [Co(Fbtx)] n network connected by the Wells–Dawson-type tungstovanadate clusters. Unexpectedly, the introduction of vanadium atoms as heteroatoms into the Dawson-type anion in polyoxometalate (POM)-based coordination polymers has not been reported to date. For the first time, the POM-based material was demonstrated to be an effective catalyst for the solvent-free ring-opening polymerization of ε-caprolactone. Moreover, the CZU-5 catalyst could be recycled up to five times with the retention of both catalytic activity and crystal structure.