Krebs-type polyoxometalate-based crystalline materials: synthesis, characterization and catalytic performance. Issue 17 (5th August 2020)

• Record Type: Journal Article
• Authors: Niu, Jia-Qi; Zhao, Qing; Xin, Xing; Zhang, Ya-Qi; Hu, Na; Ma, Yuan-Yuan; Han, Zhan-Gang
• Is Part Of: Journal of coordination chemistry. Volume 73:Issue 17/19(2020)
• Page Start: 2391
• Page End: 2401
• Publication Date: 2020-08-05
• Subjects: Polyoxometalate -- Krebs-type structure -- crystalline material -- electron transfer catalyst -- K3[Fe(CN)6] reduction; Coordination compounds -- Periodicals; 541.2242
• DOI: 10.1080/00958972.2020.1802650
• Languages: English
• ISSNs: 0095-8972

Abstract

Abstract: Three new Krebs-type polyoxometalate-based crystalline materials (H2 en)4 {[M(Hen)(H2 O)]2 (WO2 )2 (B-β-SbW9 O33 )2 }·12H2 O (M = Ni 2+ in 1, M = Co 2+ in 2, M = Mn 2+ in 3 ) (en = ethylenediamine) have been synthesized via hydrothermal method and characterized by single crystal X-ray diffraction, IR spectroscopy, X-ray powder diffraction and thermogravimetric analysis. Compounds 1 -3 display isomorphic structures and contain similar disubstituted Krebs-type {[M(Hen)(H2 O)]2 (WO2 )2 (B-β-SbW9 O33 )2 } 8- polyoxoanions, in which sandwich-type {(WO2 )2 (B-β-SbW9 O33 )2 } subunits are linked by [M(Hen)(H2 O)] 3+ fragments to form two-dimensional layer structures. By employing K3 [Fe(CN)6 ]-Na2 S2 O3 reaction as the redox model, the influence of metal linkers on the catalytic electron transfer properties of POMs have also been investigated. A series of control experiments demonstrated that the Co-disubstituted compound 2 had better catalytic performance for reducing K3 [Fe(CN)6 ] into K4 [Fe(CN)6 ] among 1 -3 . While Ni- or Mn-disubstituted compounds 1 and 3 only presented weak effect. Such differences in catalytic properties may arise from their different φ ѳ of linked heterometal atoms. The current work may provide guidance for the design of Krebs-type polyoxometalate-based heterogeneous catalysts and the exploration of catalytic redox reaction mechanism at the molecular level. Graphical Abstract: