Heterometallic Ce^IV/ V^V Oxo Clusters with Adjustable Catalytic Reactivities

Abstract

Heterometallic Ce IV /M oxo clusters are underexplored yet and can benefit from synergistic properties from combining cerium and other metal cations to produce efficient redox catalysts. Herein, we designed and synthesized a series of new Ce 12 V 6 oxo clusters with different capping ligands: Ce 12 V 6 -SO 4 , Ce 12 V 6 -OTs (OTs: toluenesulfonic acid), and Ce 12 V 6 -NBSA (NBSA: nitrobenzenesulfonic acid). Single crystal X-ray diffraction (SCXRD) for all three structures reveals a Ce 12 V 6 cubane core formulated [Ce 12 (VO) 6 O 24 ] 18+ with cerium on the edges of the cube, vanadyl capping the faces, and sulfate on the corners. While infrared spectroscopy (IR), ultraviolet−visible spectroscopy (UV− vis), electrospray ionization mass spectrometry (ESI-MS), and proton nuclear magnetic resonance ( 1 H NMR) proved the successful coordination of the organic ligands to the Ce 12 V 6 core, liquid phase 51 V NMR and small-angle X-ray scattering (SAXS) confirmed the integrity of the clusters in the organic solutions. Furthermore, functionalization of the Ce 12 V 6 core with organic ligands both provides increased solubility in term of homogeneous application and introduces porosity to the assemblies of Ce 12 V 6 -OTs and Ce 12 V 6 -NBSA in term of heterogeneous application, thus allowing more catalytic sites to be accessible and improving reactivity as compared to the nonporous and less soluble Ce 12 V 6 -SO 4 . Meanwhile, the coordinated ligands also influenced the electronic environment of the catalytic sites, in turn affecting the reactivity of the cluster, which we probed by the selective oxidation of 2-chloroethyl ethyl sulfide (CEES). This work provides a strategy to make full use of the catalytic sites within a class of inorganic sulfate capped clusters via organic ligand introduction.

Enhanced Catalytic Performance of a Ce/V Oxo Cluster through Confinement in Mesoporous SBA-15

“…We observed additional features at 1498, 1390, and 980 cm −1 which confirmed the presence of Ce−O, S−O, and V �O bonds, respectively. 35,49 The bands associated with the presence of CeV clusters exhibited increased intensity in the CeV@10SBA-4 sample versus the CeV@10SBA-2, which is consistent with increased CeV loading.…”

Cooperative Catalysis between Dual Copper Centers in a Metal–Organic Framework for Efficient Detoxification of Chemical Warfare Agent Simulants

“…Extensive work has demonstrated that detoxification of nerve agents through hydrolysis of labile P–X bonds (X = F, CN, S, etc.) is a promising route, − while for the degradation of mustard gas, selective oxidation to sulfoxide is an effective approach. ,,− Realistically, the CWAs deployed in war are usually unknown and deadly; hence, to efficiently prevent harm to human beings caused by CWAs, multifunctional catalysts that simultaneously detoxify various types of CWAs are highly desired. However, the different detoxification pathways make constructing versatile catalysts quite challenging.…”

Three New Difunctional Electrocatalysts Built from Polyoxometalates and Cu–Tpy Units: Experimental and Theoretical Study

“…Considerable efforts have been devoted to synthesizing polyoxometalates (POMs) and their derivatives in the last couple of decades thanks to their high structural modularity and tuneable applications in various fields, including nanoreactors, synthetic reaction catalysts, − electrocatalysts, − photoreduction activity, − and nanoscale materials. , First, POMs can also take on multifunctional building blocks through many active oxygen atoms on the surface in the construction of target materials, and second, POMs can serve as both electron-donating groups and high proton conductors, which have high-temperature stable nanochannels for proton conduction. − A reliable self-assembly method to design crystalline materials is to use POMs as inorganic segments and transition metal–organic constituents as linkages and generate a large number of POM-based organic–inorganic materials. They indicate synergistic effects and multifunctionalities because of various combinations of POMs and organic ingredients/metal-organic components. − For instance, Newton et al summarized self-assemblies of organo-functionalized nanomaterials based on POM building units recently; Cheng et al summed up POM-based metal–organic frameworks (PMOFs) as high-efficiency photocatalysts owing to their synergistic effect between POMs and MOFs .…”